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1: Tube DIY Asylum, RE: Direct-cupled DHSET can be tricky (0.00)
Posted by dave slagle on 2024-04-14, 14:51:37 (71.233.52.167)
MMMMMM monkey on a stick is one of my favorite audio delicacies. clippy .......
2: Tube DIY Asylum, RE: What would you use to fill in the air gap of a SE OPT? (0.00)
Posted by dave slagle on 2024-02-28, 13:51:09 (66.65.60.102)
an alternately stacked EI core will have more than double the gap area of a comparable c-core. It is the area in combination with the actual thickness of the gap that determines the effective gap. .......
3: Tube DIY Asylum, RE: What would you use to fill in the air gap of a SE OPT? (0.00)
Posted by dave slagle on 2024-02-28, 07:00:42 (67.189.163.37)
everyone is welcome to their opinion. now some really small 80% nickel R-cores would be yummy. dave .......
4: Tube DIY Asylum, RE: What would you use to fill in the air gap of a SE OPT? (0.00)
Posted by dave slagle on 2024-02-27, 13:51:37 (66.65.60.102)
actually, even if precision ground the gap is still substantial compared to an R-core, toroid or an alternately stacked EI lamination. dave .......
5: Vinyl Asylum, RE: Hagerman Piccolo Zero Headamp (0.00)
Posted by dave slagle on 2024-02-23, 06:36:28 (67.189.163.37)
There are a few issues with this line of thinking and it all falls under the general umbrella of mistracking. Unfortunately there is not a good definition of mistracking and one of the approaches to j .......
6: Vinyl Asylum, RE: Hagerman Piccolo Zero Headamp (0.00)
Posted by dave slagle on 2024-02-22, 17:45:14 (67.189.163.37)
Hey... I resemble that SUT remark :-) Been thinking about your velocity being 0 at the change in direction and one thing that is overlooked is the needle is being driven so 50% of time that 0 at the p .......
7: Vinyl Asylum, RE: Hagerman Piccolo Zero Headamp (0.00)
Posted by dave slagle on 2024-02-21, 16:31:05 (67.189.163.37)
it is intriguing to think that there might be something about cartridge designs that don't show up in voltage mode but do in current mode. I agree and on the most basic level we need to consider any .......
8: Vinyl Asylum, RE: Hagerman Piccolo Zero Headamp (0.00)
Posted by dave slagle on 2024-02-19, 18:39:52 (67.189.163.37)
As we still get signal out of the cartridge I suspect this effect is not large The "Lenz Law" flux cancellation should have no effect on the cartridge output since the coils crossing the static flux .......
9: Vinyl Asylum, RE: Hagerman Piccolo Zero Headamp (0.00)
Posted by dave slagle on 2024-02-19, 18:17:33 (67.189.163.37)
good question..... maybe a tonearm resonance test will reveal this visually in the same way your speaker test does. My next question centers around if this effect is linear with level? will a 0.5cm/se .......
10: Vinyl Asylum, RE: Hagerman Piccolo Zero Headamp (0.00)
Posted by dave slagle on 2024-02-19, 08:22:18 (67.189.163.37)
The lino blurb is the first I have seen at an attempt to quantify this and I will look at replicating this experiment. The one thorn in my paw is I find the suggestion made by many that the loading fo .......
11: Vinyl Asylum, RE: Hagerman Piccolo Zero Headamp (0.00)
Posted by dave slagle on 2024-02-19, 08:03:36 (67.189.163.37)
I think looking at the low frequency behavior is the last place to attempt to quantify this behavior for several reasons. -due to the iriaa pre-emphasis the excursion @ 10Hz is 1/10th that of 1kHz and .......
12: Vinyl Asylum, RE: Hagerman Piccolo Zero Headamp (0.00)
Posted by dave slagle on 2024-02-18, 16:09:00 (67.189.163.37)
Nice video. The key thing to remember here is this is a velocity based effect and the higher the velocity, the more the effect. It is also important to consider the riaa curve skews the highest veloci .......
13: Tube DIY Asylum, RE: Is there any way to find out if an output tranny can handle ... (0.00)
Posted by dave slagle on 2024-02-09, 05:26:24 (67.189.163.37)
PP or SE? Assuming PP, measure the cold primary DCR and the DCR after say an hour of operation for both tube types and compare. dave .......
14: Vinyl Asylum, RE: Hagerman Piccolo Zero Headamp (0.00)
Posted by dave slagle on 2024-01-31, 06:03:43 (67.189.163.37)
I have often mused that the 'unique' sound of the transimpedance approach has little to do with the nature of the amplification or the mythos surrounding the coil as a current generator and everything .......
15: Vinyl Asylum, RE: Hagerman Piccolo Zero Headamp (0.00)
Posted by dave slagle on 2024-01-31, 05:54:51 (67.189.163.37)
It is s slippery slope to attempt to quantify the concept of "dynamic braking". A few key general thoughts: -With your shorted woofer example, it is impossible to tell if the driver is shorted or not .......
16: Vinyl Asylum, RE: Hagerman Piccolo Zero Headamp (0.00)
Posted by dave slagle on 2024-01-29, 06:28:59 (67.189.163.37)
I think it is awesome that Jim came out with this product and I have one on the way. Dave .......
17: Vinyl Asylum, RE: Hagerman Piccolo Zero Headamp (0.00)
Posted by dave slagle on 2024-01-29, 06:19:18 (67.189.163.37)
I agree with the dynamic compliance changing but isn't this the nature of the beast? My disconnect here is; by presumably giving a maximum load for a cartridge a manufacturer must have determined thi .......
18: Vinyl Asylum, RE: Hagerman Piccolo Zero Headamp (0.00)
Posted by dave slagle on 2024-01-28, 11:23:45 (67.189.163.37)
The discussion I have been trying to have about these types of stages is in relation to loading. As far as I know most cartridge manufactures specify some "maximum load" which is many multiples of the .......
19: Vinyl Asylum, RE: Don't know the answer to that question but... (0.00)
Posted by dave slagle on 2024-01-27, 06:16:51 (67.189.163.37)
I agree. A single laterally oriented coil mono cartridge with both lateral and vertical compliance would be my first choice. dave .......
20: Vinyl Asylum, RE: Strapping a stereo cartridge for mono (0.00)
Posted by dave slagle on 2024-01-27, 06:14:11 (67.189.163.37)
This is really an interesting topic that I have been thinking about lately. In a perfect world where our mono in only encoded with lateral cut information, the L & R channels will have the exact same .......
21: Vinyl Asylum, RE: How about power-washing LPs? (0.00)
Posted by dave slagle on 2024-01-07, 16:33:27 (67.189.163.37)
use some water with some fine particulates and things will get really clean. dave .......
22: Vinyl Asylum, RE: SUT guidance (0.00)
Posted by dave slagle on 2024-01-02, 18:05:33 (67.189.163.37)
The short answer is a 1:2 step up ratio and a 600:50k impedance ratio cannot be from the same transformer so something must be wrong (or translated incorrectly). dave .......
23: Vinyl Asylum, RE: Relation between Fr and effective mass (0.00)
Posted by dave slagle on 2023-12-30, 12:25:34 (108.73.21.136)
good catch on the square root. it doesn't change my point that the numbers do not ever seem move as the formula suggests they should. dave .......
24: Vinyl Asylum, RE: What would happen if effective mass and compliance are mismatched? (0.00)
Posted by dave slagle on 2023-12-30, 08:37:37 (108.73.21.136)
My experiences make me side with Alex Korf on this one. The simple experiment is to double the effective mass and your fRes should be halved. I have yet to see this happen. Alex covers it much better .......
25: Vinyl Asylum, RE: VTA Adjustment Discovery......... (0.00)
Posted by dave slagle on 2023-09-30, 06:59:28 (67.189.163.37)
I find the easiest cues to SRA to be found in the sound-staging. If the SRA is too low the speakers identify themselves as being there at high frequencies. You can essentially hear the sound coming ri .......
26: Tubes Asylum, RE: EC8020 (0.00)
Posted by dave slagle on 2023-07-29, 05:01:40 (67.189.163.37)
is the EC8020ph actually a vacuum tube? The 6.3V @ 700µa "filament" that is polarized and requires DC seems odd. dave .......
27: Tube DIY Asylum, RE: Preliminary test... (0.00)
Posted by dave slagle on 2023-05-27, 04:28:29 (67.189.163.37)
Measured with a 1Ω source Z at low levels I get -1dB below 10Hz in the 1:2 autoformer configuration. Actually attempting to measure the inductance gives me values of 60mHy to 250mHy for a single .......
28: Tube DIY Asylum, RE: Preliminary test... (0.00)
Posted by dave slagle on 2023-05-26, 17:43:09 (67.189.163.37)
interesting idea... kinda just the opposite of using the speltz autoformers on OTL's. My initial concern would be the DCR's of the 120V windings are going to be on the order of your headphones or high .......
29: Tube DIY Asylum, RE: Who Was Using Toroidal PTs for Outputs? (0.00)
Posted by dave slagle on 2023-05-26, 05:22:53 (67.189.163.37)
All of the toroids that I have measured have had great bandwidth and they should be a perfect choice for your application. The two things to keep in mind are: -they are almost universally specified to .......
30: High Efficiency Speaker Asylum, RE: Autoformer and shunt resistor (0.00)
Posted by dave slagle on 2023-05-04, 07:22:27 (67.189.163.37)
for the sake of completeness... here is the simulated response of a second order crossover feeding an autoformer set to -3dB with and without the 16Ω shunt resistor. dave .......
31: Vinyl Asylum, RE: "you need to change the input resistor on your phono to 470kΩ" ... (0.00)
Posted by dave slagle on 2023-04-08, 18:36:54 (67.189.163.37)
I don't think it is as much the ability to change the resistor as it is the dogma that surrounds the sacred 47kΩ value.... that and resale value :-) dave .......
32: Vinyl Asylum, RE: Now you tell me. :-) (0.00)
Posted by dave slagle on 2023-04-08, 18:33:11 (67.189.163.37)
Its easy to listen and decide for yourself. Without the actual measured behavior of the SUT, I'll give you a coin toss as to whether it gets better or worse. The problems arise when across the board p .......
33: Vinyl Asylum, RE: Recommend me a SUT for Kiseki Blue NS (0.00)
Posted by dave slagle on 2023-04-08, 18:22:07 (67.189.163.37)
even up to 4K ohms (100x coil impedance). A SUT will not be able to deliver this ... of course a SUT can deliver 100X the 40Ω internal impedance. you need to use an active gain stage instead - .......
34: Vinyl Asylum, RE: That is very interesting. Thank you. (0.00)
Posted by dave slagle on 2023-04-08, 18:02:11 (67.189.163.37)
Nothing.... and if the SUT is in place the resistor can be removed altogether. Try explaining to someone that for MC carts the 47K load is simply an artifact put in place for a different cartridge typ .......
35: Vinyl Asylum, RE: what about what Jensen and some others do (0.00)
Posted by dave slagle on 2023-04-08, 16:09:37 (67.189.163.37)
Hey, The easiest thing to get to what I am trying to say is to read the link below. Put in a nutshell I see the 47kΩ of the typical MM as a liability but a necessary evil. Of course there will al .......
36: Vinyl Asylum, RE: what about what Jensen and some others do (0.00)
Posted by dave slagle on 2023-04-08, 05:48:26 (67.189.163.37)
I find that the worst thing you can do sonically to a transformer is to load it. It is one thing when the goal of the transformer is to deliver power since the load is a requirement of the design. It .......
37: Vinyl Asylum, RE: but as dave slagle pointed out.... (0.00)
Posted by dave slagle on 2023-04-04, 15:20:04 (67.189.163.37)
I have yet to see a MC cartridge's HF response be altered by any load. The perfect example of this is the "current mode" amplification stages which load cartridges at or below their internal impedance .......
38: Vinyl Asylum, RE: but as dave slagle pointed out.... (0.00)
Posted by dave slagle on 2023-04-04, 06:11:01 (67.189.163.37)
I tend to side with John on this one that whatever sounds best is best. However, after a desired sound is found or a pattern identified, I do have to question the validity of many of the explanations .......
39: Vinyl Asylum, RE: ok i think i got it...... (0.00)
Posted by dave slagle on 2023-04-01, 04:49:09 (67.189.163.37)
Manipulating the load on the secondary of a SUT is only a valid approach if the transformer is assumed to be perfect. In reality, altering the load on the secondary of the SUT generally has a more pro .......
40: Tube DIY Asylum, RE: Sad News : Mike LaFevre / Magnequest has Passed Away (0.00)
Posted by dave slagle on 2023-03-27, 06:30:43 (67.189.163.53)
I saw mike a few weeks back and he was happy to chat about transformers and was in good spirits. Sad to see him go. dave .......
41: Tube DIY Asylum, RE: You don't think so what? (0.00)
Posted by dave slagle on 2023-03-04, 06:59:39 (67.189.163.37)
I'm confidant that john didn't cover your approach since he is not the kinda guy to rehash the obvious. He is a genius at presenting alternative solutions to the plethora of situations that are consid .......
42: High Efficiency Speaker Asylum, RE: Is a "properly set up" autoformer using comp resistors? (nt) (0.00)
Posted by dave slagle on 2023-01-17, 13:28:41 (67.189.163.37)
Not sure what you mean by "comp". The term I use is a shunt resistor as shown in the image below. One cool trick with this is you don't need to adhere to a "standard" impedance value and an 8Ω .......
43: High Efficiency Speaker Asylum, RE: How can impedance be constant if transformer turns ratios are varied (0.00)
Posted by dave slagle on 2023-01-17, 08:49:44 (67.189.163.37)
For the sake of completeness, the range of variation of the load provided to the crossover is pretty much the same with an L-pad and a properly set up autoformer. The attached plots show the load of a .......
44: High Efficiency Speaker Asylum, RE: Are you sure about that? (0.00)
Posted by dave slagle on 2023-01-17, 05:53:42 (67.189.163.37)
fwiw, Fostex also makes a speaker level inductive unit and they also temper the varying reflected impedance by using a fixed resistor across the input. Once you get beyond say 6dB a single value resis .......
45: Tube DIY Asylum, RE: No, not really. (0.00)
Posted by dave slagle on 2022-12-28, 05:50:32 (67.189.163.37)
Whether the tube is producing HD (or not) is totally objective. in audio like most things in life, anything objective is meaningless until it is attached to the subjective. This hobby is riddled wit .......
46: Tube DIY Asylum, RE: UL Distortion (0.00)
Posted by dave slagle on 2022-12-25, 07:57:45 (67.189.163.37)
If I didn't know what the designation KT was for I would have guessed it was the typical "tetrode kink" sneaking into the UL operation. dave .......
47: Tube DIY Asylum, RE: No. UL was patented. So (0.00)
Posted by dave slagle on 2022-12-24, 09:02:41 (67.189.163.37)
Ahhh... so that is what those odd looking screen voltage numbers represent. I'm sure there is a way to step the screen voltages but I will leave that for another day. This does bring into question the .......
48: Tube DIY Asylum, RE: No. UL was patented. So (0.00)
Posted by dave slagle on 2022-12-24, 06:24:49 (67.189.163.37)
How would one trace a set of UL curves? Typical curves are simple DC operating points so the results ignore the transformer used. The AC loadline is then placed on this set of DC characteristic curve .......
49: SET Asylum, RE: Hi B+ on Morrison Micro (moved from Tube DIY Asylum) (0.00)
Posted by dave slagle on 2022-12-12, 12:35:19 (67.189.163.37)
it should... unlike the sovtek 2A3 which according to JC has a different cathode composition than the 300B, the JJ 2A3 lists the same 40W of plate dissipation as the 300B. dave .......
50: Speaker Asylum, RE: what's that on top? The standard unit of value when buying a speaker (0.00)
Posted by dave slagle on 2022-12-12, 05:11:38 (67.189.163.37)
I actually think that is a very unique prototype sequerra ribbon since it fires in three directions (Front, Left and Right). dave .......
51: Speaker Asylum, Dick Sequerra's Personal speakers (0.00)
Posted by dave slagle on 2022-12-11, 08:52:04 (67.189.163.37)
Below is a link to an auction of the system Dick Sequerra was using when he passed away a year ago that might be of interest here. dave .......
52: SET Asylum, RE: Hi B+ on Morrison Micro (moved from Tube DIY Asylum) (0.00)
Posted by dave slagle on 2022-12-09, 18:25:01 (67.189.163.37)
Well.... since JC had a hand in the design of the Sovtek 2A3 I kinda think you will be OK. There was a conversation with him it seems like 20 years ago on the Joenet where he explained that even thoug .......
53: SET Asylum, RE: Hi B+ on Morrison Micro (moved from Tube DIY Asylum) (0.00)
Posted by dave slagle on 2022-12-09, 18:20:37 (67.189.163.37)
I would first determine the needed cap value and then you can experiment with different types. The last thing you want to be doing is spending $$$ on fancy parts that may or may not be the right value .......
54: SET Asylum, RE: Hi B+ on Morrison Micro (moved from Tube DIY Asylum) (0.00)
Posted by dave slagle on 2022-12-09, 18:17:56 (67.189.163.37)
I find they sound better in this application. dave .......
55: SET Asylum, RE: Hi B+ on Morrison Micro (moved from Tube DIY Asylum) (0.00)
Posted by dave slagle on 2022-12-09, 05:39:32 (67.189.163.37)
I know that Morrison purposely runs the tubes hot and out of spec. JC didn't advocate for the abuse of all tubes, just specifically the bi-plate 2A3. He has always insisted that the 15W max plate di .......
56: Tube DIY Asylum, RE: Engineering is always a tradeoff. (0.00)
Posted by dave slagle on 2022-11-18, 04:43:45 (67.189.163.37)
It depends on the transformer use. In the early days when all of the insulations were organic, impregnation was mandatory for long life but as new types of insulations became available this 'absolute .......
57: Vinyl Asylum, RE: Need Help with Panasonic/Technics Strain Gauge (0.00)
Posted by dave slagle on 2022-09-03, 17:07:22 (67.189.163.37)
Hey, there should be 6-12V across the strain gauge inputs to power the cartridge. clip a meter to the cartridge leads so it reads 832Ω then tweak the cantilever and see if the resistance changes. (it .......
58: Vinyl Asylum, RE: Need Help with Panasonic/Technics Strain Gauge (0.00)
Posted by dave slagle on 2022-09-03, 05:25:52 (67.189.163.37)
you can measure the DCR of the cartridge to judge its condition... it should measure between 800 and 1200Ω dave .......
59: Vinyl Asylum, RE: A passing (0.00)
Posted by dave slagle on 2022-08-21, 04:46:49 (67.189.163.37)
sincere condolences. I too can find some dupes for you.... what kind of music do you listen to? dave .......
60: Tube DIY Asylum, RE: Sanity check (0.00)
Posted by dave slagle on 2022-08-21, 04:36:37 (67.189.163.37)
good suggestion on the 91k change. dave .......
61: Vinyl Asylum, RE: Shibata vs. Line Contact Styli...... (0.00)
Posted by dave slagle on 2022-08-03, 18:12:30 (67.189.163.37)
I have not measured this... the measurement data was enclosed with the styli from Namiki. They give the measured results from three sample from each lot and I have the following three sets of measurem .......
62: Vinyl Asylum, RE: Shibata vs. Line Contact Styli...... (0.00)
Posted by dave slagle on 2022-08-03, 05:35:50 (67.189.163.37)
For this reason, I have shifted to using a V15Type V with JICO SAS styli on the Sapphire pipe which are laser cut with a hole for the SAS stylus to ensure zenith accuracy when I need the capability o .......
63: Vinyl Asylum, RE: Makes you wonder... (0.00)
Posted by dave slagle on 2022-07-13, 13:09:35 (67.189.163.37)
I love the thought of a 12" wax cylinder. dave .......
64: Vinyl Asylum, RE: Vinyl Ponderable.... (0.00)
Posted by dave slagle on 2022-07-13, 04:39:42 (67.189.163.37)
A good analogy was given to me by a cutting engineer. The lead-in groove is like 30ips tape and the lead-out groove is like a cassette taps. Granted that is a bit overdramatic but it gets the point ac .......
65: Tube DIY Asylum, RE: FU50 tube (0.00)
Posted by dave slagle on 2022-07-12, 04:57:14 (67.189.163.37)
The thing that bothers me about the GU-50 curves is that they seem to hit the 0ma Ia point too abruptly. In a perfect world there should be no abrupt bends and each curve should originate at the (0,0) .......
66: Tube DIY Asylum, RE: Ping Dave Slagle: SPICE Distortion (0.00)
Posted by dave slagle on 2022-07-07, 19:34:38 (67.189.163.37)
Got the file and I get similar numbers to yours but the overload characteristics are not pretty.... this stage clips pretty hard but the ugliness doesn't show up until about 140V peak so you seem to t .......
67: Tube DIY Asylum, RE: Distortion (0.00)
Posted by dave slagle on 2022-07-05, 13:03:35 (67.189.163.37)
As far as I know, spice simply does the same thing that you would do to graphically calculate the distortion and I trust a computer with math a hell of a lot more than I trust paper and a ruler. I thi .......
68: Tube DIY Asylum, RE: What's the HD going to be? nt (0.00)
Posted by dave slagle on 2022-06-30, 04:41:32 (67.189.163.37)
If you can trust spice ;-) I get a gain of 4.5 and the following distortion spectra. (first line value of "a" is the input voltage) .step a=1 N-Period=1 Fourier components of V(output) DC component .......
69: Tube DIY Asylum, RE: How can A2 happen in 845 (0.00)
Posted by dave slagle on 2022-06-26, 05:00:05 (67.189.163.37)
This becomes an interesting 'cup is 1/2 full' situation. Which is better? 1) a situation where the grid is really easy to drive 90% of the time and on the occasional dynamic peak it becomes nearly imp .......
70: Vinyl Asylum, RE: Does he remove the stylus & keep the cantilever? (0.00)
Posted by dave slagle on 2022-06-23, 05:02:14 (67.189.163.37)
I know he can retain the original cantilever and install a new diamond. He is very knowledgeable and sharing with information. dave .......
71: Tube DIY Asylum, RE: How can A2 happen in 845 (0.00)
Posted by dave slagle on 2022-06-15, 08:40:02 (67.189.163.37)
Ahhh... thanks! I knew I was making a simple mistake, dave .......
72: Tube DIY Asylum, RE: How can A2 happen in 845 (0.00)
Posted by dave slagle on 2022-06-15, 06:08:17 (67.189.163.37)
Hey, That is the exact way you figure out the graphical Rp of a tube. Draw a line tangent to the operating point on the curves and rP=dV/dI. However when I look at the grid curves the slope of the lin .......
73: Tube DIY Asylum, RE: How can A2 happen in 845 (0.00)
Posted by dave slagle on 2022-06-14, 17:59:31 (67.189.163.37)
Is there a way to graphically determine the grid impedance from the grid current curves like you can do for plate impedance from the plate curves? The other thing to note about the OP is that very lit .......
74: Tubes Asylum, RE: that question is non-sequitur (0.00)
Posted by dave slagle on 2022-06-10, 05:47:49 (67.189.163.37)
It is interesting that in order to correctly read the text correctly RCA's world view is shifted 90° and puts the americas in the center rather that the OP's arrangement that shows the world as tra .......
75: Tube DIY Asylum, RE: +1 (0.00)
Posted by dave slagle on 2022-05-30, 17:25:01 (67.189.163.37)
It is all about the wheels.... .......
76: Tube DIY Asylum, RE: interesting read on cap input vs choke input (0.00)
Posted by dave slagle on 2022-05-18, 04:35:53 (67.189.163.37)
Strangely, output transformers get lots of attention with respect to suppressing leakage inductance by audio enthusiasts, but the power transformer gets no thought. From my quick perusal of the arti .......
77: Tubes Asylum, RE: It was a military stratagem. (0.00)
Posted by dave slagle on 2022-05-17, 04:07:06 (67.189.163.37)
The one flaw in this thought is the tubes were for their own military. Now if they were to gold plate the pins and label the Telefunken ECC-803s soldiers who found them would surely drop their weapons .......
78: Tubes Asylum, RE: In the middle it is also 6J11P. nt (0.00)
Posted by dave slagle on 2022-05-15, 06:11:48 (67.189.163.37)
if you trust the writing on the middle tube then it is a 6J11 which is a pentode however if you look at the parts inside the glass it is identical to the 6C45 which is a triode. Pins 1, 3, 6 and 9 are .......
79: Tubes Asylum, Russian tube question. (0.00)
Posted by dave slagle on 2022-05-11, 18:03:37 (67.189.163.37)
I can confirm the left tube is a 6J11 and the right tube is a 6C45 but what does that make the middle tube??? dave .......
80: Tube DIY Asylum, RE: the freq is 400hz..-nt (0.00)
Posted by dave slagle on 2022-04-09, 14:01:13 (67.189.163.37)
cap or inductor is going to produce ellipse. they're both reactance. yes... if they are the load. a coupling capacitor is not a load, it is in series with the load so it needs to be treated as such. .......
81: Tube DIY Asylum, RE: the freq is 400hz..-nt (0.00)
Posted by dave slagle on 2022-04-09, 06:57:28 (67.189.163.37)
How does RC coupling work into the concept of an elliptical load? He mentions he covers it in his video on "Dynamic Path Operation" but I was unable to locate that series. dave .......
82: Tube DIY Asylum, RE: the freq is 400hz..-nt (0.00)
Posted by dave slagle on 2022-04-08, 06:25:43 (67.189.163.37)
wow... for 400hz I need to use either 50hy of inductance or 5nF of capacitance to get the ellipse to open up that far. Either would be a deal breaker for anything in an audio circuit. dave ::: TOPIC:: .......
83: Tube DIY Asylum, RE: this will be the coolest thing you see all day (0.00)
Posted by dave slagle on 2022-04-04, 11:43:24 (67.189.163.37)
The other video he references covers the dynamic load for low frequency behavior where inductance causes the ellipse. However the sample he goes 3D on is for a 12AX7 so I would guess he is looking at .......
84: Tube DIY Asylum, RE: this will be the coolest thing you see all day (0.00)
Posted by dave slagle on 2022-04-04, 10:33:26 (67.189.163.37)
Does he give the source of the elliptical loadline and the frequency of the tests? .......
85: Tube DIY Asylum, RE: That reminded me... (0.00)
Posted by dave slagle on 2022-04-03, 14:41:31 (67.189.163.37)
I presume you are talking about push pull here. I think it comes down to the concept that the composite curves you use for PP appear as a set of straight parallel lines. Stephie bench gets pretty d .......
86: Tube DIY Asylum, RE: read (0.00)
Posted by dave slagle on 2022-04-03, 11:45:55 (67.189.163.37)
My though was a gedanken one about using a CCS for the cathodyne inverter after it was suggested above that it was not possible. Personally I would forgo the sand and use a good old fashioned nickel c .......
87: Tube DIY Asylum, RE: Question for Tre' or (0.00)
Posted by dave slagle on 2022-04-02, 07:30:54 (67.189.163.37)
OK.... Lets have some fun here :-) In a perfect world like the one that exists in spice where two CCS can live happily in series I see no reason why a split load inverter couldn't be done with a pair .......
88: Tube DIY Asylum, RE: Reading up on breakdown voltage, . . (0.00)
Posted by dave slagle on 2022-03-27, 11:59:45 (67.189.163.37)
The maximum voltage end-to-end is often called working voltage, presumably to protect against internal arcing. A rating higher than 500v is rare, except for specifically high-voltage-rated resistors .......
89: Tube DIY Asylum, RE: Reading up on breakdown voltage, . . (0.00)
Posted by dave slagle on 2022-03-27, 06:05:39 (67.189.163.37)
I see two distinctly different an unrelated things getting confused here. The maximum voltage across a part due to the I^2 R limit of the part and the maximum voltage the part as a whole can withstand .......
90: Tube DIY Asylum, RE: 12.5K NT (0.00)
Posted by dave slagle on 2022-03-26, 14:49:11 (67.189.163.37)
So the voltage you are worrying about is the voltage from either end or the body of the resistor to ground and not the voltage "across the resistor". does anyone have a good definition of what is mea .......
91: Tube DIY Asylum, RE: I have 600 volts going across a 2 watt resistor but . . (0.00)
Posted by dave slagle on 2022-03-26, 06:44:21 (67.189.163.37)
out of curiosity, what is the value of the resistor? dave .......
92: Vinyl Asylum, RE: audio tekne 9448 SUT - how to use this thing? (0.00)
Posted by dave slagle on 2022-03-15, 05:37:39 (67.189.163.37)
I looks like the high setting is listed as 10Ω:4kΩ (1:20) and the low setting is 100Ω:4KΩ (1:6.3). The 4kΩ secondary number is curious and could be read a couple of different .......
93: Vinyl Asylum, RE: :-0 Certainly.. no arguement .. (0.00)
Posted by dave slagle on 2022-03-08, 04:42:29 (67.189.163.37)
I think you ask a valid question about the coupling and I would like to see more discussion about it. I recall reading in an article from back in the day where the author stated that lossy isolation w .......
94: Tube DIY Asylum, RE: How to use a bolt to improve hum spectrum (0.00)
Posted by dave slagle on 2022-03-03, 10:36:57 (67.189.163.37)
There is a reason they do not use solid slugs of steel for high frequency inductors.... or inductors in general for that matter. I doubt the device you simmed and the device you built are remotely sim .......
95: Tube DIY Asylum, RE: How to use a bolt to improve hum spectrum (0.00)
Posted by dave slagle on 2022-03-03, 10:11:55 (67.189.163.37)
I am not referring to saturation but the the high eddy current losses from a solid chunk of iron. Ferrites are powdered to avoid this and laminations / tapes are made increasingly thinner as the suppo .......
96: Tube DIY Asylum, RE: How to use a bolt to improve hum spectrum (0.00)
Posted by dave slagle on 2022-03-03, 09:11:47 (67.189.163.37)
Any idea what the cause of the increased noise floor is? Have you confirmed the behavior of the "boltductor" compared to the ideal that is represented in the simulation. I would guess that for the fre .......
97: Tube DIY Asylum, RE: How to use a bolt to improve hum spectrum (0.00)
Posted by dave slagle on 2022-03-03, 07:55:12 (67.189.163.37)
If you look closely the 50Hz signal in both is at -63dB and moving to the 150Hz the noise floor in your "preferred one" obscures it. Here are the two FFT's overlapped and I suspect if you dropped t .......
98: Tube DIY Asylum, RE: How to use a bolt to improve hum spectrum (0.00)
Posted by dave slagle on 2022-03-03, 04:42:53 (67.189.163.37)
I do not completely follow your thinking here. The two spectra you post are different but I am not sure which one I would consider "better". The top spectra has a higher noise floor but the harmonics .......
99: Tube DIY Asylum, RE: NC-20 (0.00)
Posted by dave slagle on 2022-02-16, 15:34:30 (67.189.163.37)
The dulling of the sound is my subjective impression. I have never found loading to help the sound of a transformer and in the cases where it did it was due to damping of a HF resonance too close to t .......
100: Tube DIY Asylum, RE: Hammond Interstage Transformers (0.00)
Posted by dave slagle on 2022-02-16, 06:08:28 (67.189.163.37)
To dive deeper into the whole issue of loading you have to determine the reason of the load. Limiting things to tube audio I see several distinctly different situations that people tend to lump togeth .......
101: Tube DIY Asylum, RE: Hammond Interstage Transformers (0.00)
Posted by dave slagle on 2022-02-14, 06:29:55 (67.189.163.37)
I would encourage you to simply run a simple frequency sweep of the transformer you intend to use loaded @ 2KΩ before you commit to the design. The full story on this popped into my mind about 1 .......
102: Tube DIY Asylum, RE: Hammond Interstage Transformers (0.00)
Posted by dave slagle on 2022-02-13, 15:00:36 (67.189.163.37)
Putting a 10K impedance number on a bifilar interstage is a silly thing to do since loading it with 10K will assure a rising frequency response above 1kHz. For the most part, transformers used with tr .......
103: Tube DIY Asylum, RE: Hammond Interstage Transformers (0.00)
Posted by dave slagle on 2022-02-13, 10:46:57 (67.189.163.37)
The 126 series is bifilar and under no circumstance should you ever load the secondary of a high impedance DC carrying bifilar transformer if you want flat frequency response. The 126 series also cann .......
104: SET Asylum, RE: cost of SET (0.00)
Posted by dave slagle on 2022-02-06, 07:09:36 (67.189.163.37)
Wouldn't class A PP have to be compared to Class A Parallel SE? At which point the power would be similar negating much of the 2X argument..... the two big differences in cost would be the output tran .......
105: Tubes Asylum, My method works with a single whack.... (0.00)
Posted by dave slagle on 2022-02-05, 06:36:51 (67.189.163.37)
Of course I needed two of them for stereo. .......
106: Tube DIY Asylum, RE: Western Electric 91E use push pull ? (0.00)
Posted by dave slagle on 2022-02-02, 06:24:32 (67.189.163.37)
From Broskie... The patent claims that this a para-feed arrangement, but really is just a push-pull totem-pole arrangement of dissimilar output devices with a coupling capacitor attaching to the outpu .......
107: Tube DIY Asylum, RE: Output impedance (0.00)
Posted by dave slagle on 2022-02-02, 06:11:20 (67.189.163.37)
It is interesting that in transient mode spice will allow for a .wav file to be input and then the results exported and listened to. I have never tried it but it would in theory let you listen to some .......
108: Tube DIY Asylum, RE: Output impedance (0.00)
Posted by dave slagle on 2022-02-01, 13:05:56 (67.189.163.37)
How do you measure and asses the output impedance of a design that hasn't been built yet? I find spice to be a valuable design and troubleshooting tool and lets you know the basic behavior prior to br .......
109: Tube DIY Asylum, RE: Output impedance (0.00)
Posted by dave slagle on 2022-02-01, 12:59:55 (67.189.163.37)
Yup... I left my 1F 100V supercap in my other amp.... dave .......
110: Tube DIY Asylum, RE: Output impedance (0.00)
Posted by dave slagle on 2022-02-01, 05:21:37 (67.189.163.37)
Another (possibly easier) way to check the impedance at any node is to simply drive that node with an AC current of 1A. Then left click on the vertical scale and select linear. Since Z=V/I and I=1, th .......
111: Tube DIY Asylum, RE: Quick Question: What is a fully balanced Single Ended amp? (0.00)
Posted by dave slagle on 2022-01-20, 05:58:00 (67.189.163.37)
I'm guessing a typo... add a zero to the 30Hy and the numbers all seem to add up. dave .......
112: Tube DIY Asylum, RE: UK is 50 Hz land so... (0.00)
Posted by dave slagle on 2022-01-10, 11:30:45 (67.189.163.37)
that was my guess too but I read BPM as beats per minute which suggests a very low frequency. dave .......
113: SET Asylum, RE: genalex gold lion 2a3 (0.00)
Posted by dave slagle on 2022-01-10, 07:24:20 (67.189.163.37)
Thats OK.... Western Electric never mad an 845 but that doesn't prevent someone from making and selling WE replica 845's dave .......
114: Tube DIY Asylum, RE: Both sections would be lit all the time unless they have a 6SN7 of which no-one was previously aware... nt (0.00)
Posted by dave slagle on 2022-01-05, 12:45:52 (67.189.163.37)
I was just referring to cool swap as a possible explanation of the "dead section" and mentioned that the series wiring of the filaments prevented this possibility.... so onto the real question.... why .......
115: Tube DIY Asylum, RE: What would be the sonic effect for this Audionote line stage (0.00)
Posted by dave slagle on 2022-01-04, 17:44:46 (67.189.163.37)
Like TK I have to wonder about the "dead" sections. My first thought was they were doing a "cool swap" like john atwood designed into the Artemis Labs stuff but the same section is called out in both .......
116: Tube DIY Asylum, RE: 300B IT 1:1 845, A2 possible? (0.00)
Posted by dave slagle on 2021-12-28, 07:39:10 (67.189.163.37)
A 300B has a rP in excess of 1kΩ @ 30ma and then both the primary and secondary DCR needs to be added to those numbers which will take the drive impedance up even higher. I think there is a gener .......
117: Tube DIY Asylum, RE: Alodine / Iridite Chromate Conversion (0.00)
Posted by dave slagle on 2021-12-28, 07:21:41 (67.189.163.37)
I searched a few years back for alodine solutions and came up blank so I am very interested in your experiments... please keep us informed. dave .......
118: Tube DIY Asylum, RE: Tre, do you know how they calculated that 4.2mA value? (0.00)
Posted by dave slagle on 2021-12-14, 15:31:33 (67.189.163.37)
You also have 375V on one side of the 4.7K dropping resistor and 320V on the other. If one is to trust Messrs. Ohm and Kirchoff then both tubes together should be running 11.7ma or around 50% more tha .......
119: Tube DIY Asylum, RE: LTSpice Model for 6BL7 or 6BX7 ? (0.00)
Posted by dave slagle on 2021-12-12, 19:07:37 (67.189.163.37)
these are the two I use... * 6BX7 LTSpice model .subckt 6BX7 P G K Cgp G P 4.1p Ci G K 4.6p Co P K 1.1p Bp P K I=(0.1224730616m)*uramp(V(P,K)*ln(1.0+(-0.1210285278)+exp((3.773423323)+(3.77342332 .......
120: Vinyl Asylum, RE: ME passed the microscope test at my house, too... (0.00)
Posted by dave slagle on 2021-12-01, 08:09:51 (67.189.163.37)
If you lock the tonearm in the armrest and bury the diamond n the ME and then apply force at 90° then maybe something bad may happen but that is 100% counter to every stylus cleaning process ever. I a .......
121: Vinyl Asylum, RE: ME passed the microscope test at my house, too... (0.00)
Posted by dave slagle on 2021-11-30, 17:29:32 (67.189.163.37)
Exactly. The force the diamond sees in the groove has to be several orders of magnitude greater than ME could ever possibly exert. All you have to do is look closely under your microscope at how the d .......
122: Vinyl Asylum, RE: ME passed the microscope test at my house, too... (0.00)
Posted by dave slagle on 2021-11-30, 09:00:27 (67.189.163.37)
I don't get all of these warnings against using ME like a stylus brush for fear of ripping the diamond or cantilever off. If ME ever had a chance of doing that kind of damage, the first side of a reco .......
123: Tube DIY Asylum, RE: I avoid gear using 6SN7 tubes (0.00)
Posted by dave slagle on 2021-11-27, 07:23:48 (67.189.163.37)
Wow... that is an interesting data sheet. The quirk that jumped out at me is with regard to the Ri, Gm and µ graph. From the numbers below and using the formula Ri=µ/Gm I get an Ri of 7166Ω b .......
124: Tube DIY Asylum, RE: 394a tube and Hickok 539 tester (0.00)
Posted by dave slagle on 2021-11-21, 05:49:58 (67.189.163.37)
it might... I seem to recall a reference was required to get reasonably stable / consistent / predictable operation. I do think that the proper way to diode wire it is to simply connect the grid to th .......
125: Tube DIY Asylum, RE: Choke Phase (0.00)
Posted by dave slagle on 2021-11-20, 17:00:12 (67.189.163.37)
Right.... in both cased the cathodes are AC coupled to each other. A single choke has them direct coupled to each other and the "dual winding choke" actually is a 1:1 transformer. I actually consider .......
126: Tube DIY Asylum, RE: Choke Phase (0.00)
Posted by dave slagle on 2021-11-19, 16:51:18 (67.189.163.37)
These two circuits are functionally the same except the one with the dual winding choke will allow for each tube to be biased independently. In both cases the choke must handle the full idle DC of .......
127: Tube DIY Asylum, RE: Single capacitor doesn't work (0.00)
Posted by dave slagle on 2021-11-17, 10:28:36 (67.189.163.37)
Class B is not possible with this design since as one tube shuts off the other will also shut off due to the series circuit. Tre' pointed you to the link on the concept that is generally associated wi .......
128: Tube DIY Asylum, RE: FMECA considerations in PP with current source (0.00)
Posted by dave slagle on 2021-11-17, 05:35:38 (67.189.163.37)
My understanding is that the goal for many of using a single CCS (or to some extent a single unbypassed resistor) is to "forces balance" between the tubes. An added plus for many is the removal of the .......
129: Tube DIY Asylum, RE: 394a tube and Hickok 539 tester (0.00)
Posted by dave slagle on 2021-11-15, 05:32:46 (67.189.163.37)
they need to be "diode wired" to get the full potential. The best way to do that is a question for debate. I have historically used a 1K resistor to reference the grid to the plate and limit current t .......
130: Tube DIY Asylum, RE: 394a tube and Hickok 539 tester (0.00)
Posted by dave slagle on 2021-11-12, 05:35:24 (67.189.163.37)
I do like the tube and have been using it as a rectifier for 20 years. There are a couple of considerations. If you will be supplying the tube less than say 250Vac then you can forgo the top cap and s .......
131: Tube DIY Asylum, RE: 394a tube and Hickok 539 tester (0.00)
Posted by dave slagle on 2021-11-11, 10:58:07 (67.189.163.37)
Test it as what... a thyratron or a mercury rectifier? dave .......
132: Tube DIY Asylum, RE: First time in over 20 years I disagree with one of your opinions (0.00)
Posted by dave slagle on 2021-10-02, 07:04:50 (67.189.163.37)
well put! If the concept of "reproducing" is a technical endeavor, that suggests there should be a universal agreed upon solution. The fact that that solution does not exist supports the concept that .......
133: SET Asylum, RE: I think I found one of those articles (0.00)
Posted by dave slagle on 2021-09-24, 14:52:26 (67.189.163.37)
the two things that strike me in the article (and the linked article by Lynn Olson) that jump out at me are this thought referenced to Norman Crowhurst: Research by Norman Crowhurst points out that f .......
134: SET Asylum, RE: harmonics added (0.00)
Posted by dave slagle on 2021-09-20, 15:45:40 (67.189.163.37)
I am specifically looking for a citing in support of the following statement: The 2nd and 3rd are relatively innocuous so the ear can tolerate a lot of it. this seems to suggest they are on equal foo .......
135: SET Asylum, RE: I'll have to dig it up. I've read several articles on this topic (0.00)
Posted by dave slagle on 2021-09-17, 14:58:54 (67.189.163.37)
I'd like pointers to the articles. It is interesting that Nelson wrote the linked info back in 2013 and since then I hear he has been playing with the phase of the harmonics in successive stages so a .......
136: SET Asylum, RE: Its not my requirements. (0.00)
Posted by dave slagle on 2021-09-16, 06:00:29 (67.189.163.37)
If there isn't a nice 2nd or 3rd harmonic to mask the higher orders Hey Ralph, do you have a good reference on this? I have seen it mentioned in passing but have never seen a good paper on the conce .......
137: Tube DIY Asylum, RE: Krohn Hite UF-101 6550 testing data. (0.00)
Posted by dave slagle on 2021-09-01, 09:23:05 (67.189.163.37)
the rub here is it is not UL but unity coupled where the screen of positive going tube A is connected to the plate of negative going tube B. This means that the screen is swinging in the opposite dire .......
138: Tube DIY Asylum, RE: Krohn Hite UF-101 6550 testing data. (0.00)
Posted by dave slagle on 2021-08-31, 17:40:05 (67.189.163.37)
bias voltage is -57 at the grid of the outputs and there is 6.3V at the cathode for a total bias of 63.3V Three rando test results of tubes I have with 540 anode and 540 screen and -63.3V bias Tung So .......
139: Tube DIY Asylum, Krohn Hite UF-101 6550 testing data. (0.00)
Posted by dave slagle on 2021-08-31, 14:33:41 (67.189.163.37)
I have a friend who needs to retube a Krohn Hite UF-101 amp and in looking at the schematic it appears to be similar to the mac unity coupled designs. From the manual it states that the plates and scr .......
140: Tubes Asylum, RE: The (long) Story So Far ~pics~ (0.00)
Posted by dave slagle on 2021-08-02, 06:37:59 (67.189.163.37)
just singles... that western 241 is on my wish list of albatrosses... µ16 rP of 2000.... basically a 212 with a top cap. dave .......
141: Vinyl Asylum, RE: I guess this gets very complex if you think about it. (0.00)
Posted by dave slagle on 2021-07-30, 07:06:59 (67.189.163.37)
Thanks for the kind words... For anyone that wants to dig deeper into the interactions at play they can look at the advertorial linked below :-) dave .......
142: Vinyl Asylum, RE: I guess this gets very complex if you think about it. (0.00)
Posted by dave slagle on 2021-07-29, 19:19:33 (67.189.163.37)
Hey, I'll reply with my thoughts inline below... What is the typical inductance of the primary winding of a phono SUT? That is a tough question to answer. General practice is to throw the kitchen si .......
143: Vinyl Asylum, RE: The quote from Henley (0.00)
Posted by dave slagle on 2021-07-29, 06:31:30 (67.189.163.37)
I'm sure he is referring to the primary inductance which appears in parallel with the reflected load. This value changes at a rate of 2Ï€FL. (2*pi*Frequency*Inductance) This means that every octave you .......
144: Tube DIY Asylum, RE: Bottlehead c4s (0.00)
Posted by dave slagle on 2021-07-21, 13:52:54 (174.197.199.97)
they have been claimed dave .......
145: Tube DIY Asylum, Bottlehead c4s (0.00)
Posted by dave slagle on 2021-07-21, 06:50:17 (67.189.163.37)
Somewhere I cam across this stash of what is labeled c4s boards and parts and they are free to anyone who wants them. I'll cover shipping in the states. No guarantees on anything... so you get w .......
146: High Efficiency Speaker Asylum, RE: Bruce Edgar's hand drawn schematic for Edgar Salad Bowl (0.00)
Posted by dave slagle on 2021-07-16, 06:15:02 (67.189.163.37)
What does the impedance curve of the 2441H look like? The first thing that comes to mind is since there is attenuation anyways, you can parallel a pure resistance with the impedance curve to "temper i .......
147: SET Asylum, RE: Something New Under the Sun? (0.00)
Posted by dave slagle on 2021-06-14, 07:05:43 (67.189.163.37)
Assuming Broskie is correct, I would be interested in seeing the distortion spectra of this amp. I wonder if it is the case where the 300B has the expected SE triode distortion spectra and the mosfet .......
148: Tube DIY Asylum, RE: Dave... (0.00)
Posted by dave slagle on 2021-06-14, 06:55:00 (67.189.163.37)
I initially simmed this with a cascoded 10m45 since I already had the circuit built and indeed the values needed to be matched which seemed to confirm TK's original criticism. Then I went to a single .......
149: Tube DIY Asylum, RE: TubeCad Error re: LTP? (0.00)
Posted by dave slagle on 2021-06-12, 08:14:59 (71.114.93.179)
If you assume a "perfect" CCS then I agree but it is you who added the "perfect" part and not broskie. how close the "average" ccs is to the ideal and how closely matched the outputs need to be is ope .......
150: Tube DIY Asylum, RE: TubeCad Error re: LTP? (0.00)
Posted by dave slagle on 2021-06-11, 04:43:47 (67.189.163.37)
I fail to see the error. The closer the CCS is to ideal the closer the two plate resistors would need to be in value and in theory a perfect CCS with identical tubes would result in the need for match .......
151: Tube DIY Asylum, RE: It's a spectrum (0.00)
Posted by dave slagle on 2021-06-09, 09:06:20 (67.189.163.37)
Agree on the bell curve. The interesting thing about the bell curve aspect is while the majority fall within the 70% in the middle, the 13% on either side are still lucid and rational. What I find int .......
152: Tube DIY Asylum, RE: Cap Value (0.00)
Posted by dave slagle on 2021-06-07, 04:33:17 (67.189.163.37)
Again, it comes down to a question of how small is small enough exactly... this was my point when I enter this conversation. like many things in audio everything is factual until you get down to the .......
153: Tube DIY Asylum, RE: Cap Value (0.00)
Posted by dave slagle on 2021-06-06, 19:33:16 (67.189.163.37)
So I took a 300B biased with a 750Ω resistor (59V bias 78ma 375V B+) and bypassed it with a 135µ cap to get a -3dB point of 2hz. I then fed 50Vac into the grid and the plot below shows the AC acr .......
154: Tube DIY Asylum, RE: Fools Errand. (0.00)
Posted by dave slagle on 2021-06-06, 18:03:21 (67.189.163.37)
IF you accept #1 and #2 as factual, then how can you not also agree that if made large enough a capacitor cannot impart any sound on an amp? Ok that is a bit extreme so how about the bigger you make a .......
155: Tube DIY Asylum, Fools Errand. (0.00)
Posted by dave slagle on 2021-06-06, 07:48:05 (67.189.163.37)
Fools Errands come in may shapes and forms. Loosely attaching a solid engineering theory to an observed occurrence no longer is a factual event. Attaching known facts and unassailable theory does not .......
156: Tube DIY Asylum, RE: Transformers buzzing (RCA 203 SE 6BQ5 amp and VPI PLC speed controller) (0.00)
Posted by dave slagle on 2021-06-06, 07:25:37 (67.189.163.37)
I was playing with a green wave EMI meter and their supplied filter to see if anything was to be gained. Turns out that plugging transformers in increases the measured EMI on the line and their filter .......
157: Tube DIY Asylum, RE: Cap Value (0.00)
Posted by dave slagle on 2021-06-04, 05:41:46 (67.189.163.37)
The big flaw I see in your supposition is you never get 0Vac across a cap. At some point the value will "get so small it can't matter" but that is a subjective call and needs to be put through the sam .......
158: Tube DIY Asylum, RE: You're entitled to be wrong. :) (0.00)
Posted by dave slagle on 2021-06-03, 04:43:16 (67.189.163.37)
the logical end to this line of thought is if you make caps large enough in value, they become inaudible. By extension... if you hear the difference between cap types, you are simply using too small a .......
159: Tube DIY Asylum, RE: Getting used to... (0.00)
Posted by dave slagle on 2021-06-02, 05:14:47 (67.189.163.37)
All of these "by-ear" evals are meaningless as are all of the the "if it measures the same it must sound the same" and the "if you can't measure an AC voltage it can't change the sound". Like politi .......
160: Vinyl Asylum, RE: Ultrasonic Record Cleaning at 80khz (0.00)
Posted by dave slagle on 2021-05-27, 07:33:59 (67.189.163.37)
and... Neal Antin does a thorough treatment of all methods of record cleaning in his treatise on the subject at the link below. .......
161: Vinyl Asylum, RE: Ultrasonic Record Cleaning at 80khz (0.00)
Posted by dave slagle on 2021-05-27, 07:32:08 (67.189.163.37)
The general thoughts I have gathered thus far is the lower frequencies are best for aggressive cleaning of the surface of the record and the higher frequencies are best to gently get to the bottom of .......
162: Tube DIY Asylum, RE: LCR Phono stage (0.00)
Posted by dave slagle on 2021-05-02, 06:06:44 (67.189.163.37)
The problem with measurements and sims for that matter is they only show you what the presenter wants you to see. You were trying to show how perfect a 50K pot was but fed it into an unrealistic 15pf .......
163: Tube DIY Asylum, RE: LCR Phono stage (0.00)
Posted by dave slagle on 2021-05-01, 07:49:41 (67.189.163.37)
What is there not to understand? It has been my contention that benevolently driving a 600Ω load is not an easy thing to do independent of it being resistive or reactive. Since this is about 600& .......
164: Tube DIY Asylum, RE: LCR Phono stage (0.00)
Posted by dave slagle on 2021-05-01, 07:33:17 (67.189.163.37)
5K output impedance? where did you get that number from? Did you read the source impedance of 500Ω in the plot title as 5000? The full details including full bandwidth response against source im .......
165: Tube DIY Asylum, RE: LCR Phono stage (0.00)
Posted by dave slagle on 2021-04-30, 17:17:40 (67.189.163.37)
That isn't necessarily representative of all magnetic volume controls. .......
166: Tube DIY Asylum, RE: LCR Phono stage (0.00)
Posted by dave slagle on 2021-04-30, 13:59:27 (67.189.163.37)
figure 200hy's so 25KΩ. I have had several people use them with tubes like the 26, 27, 56 or 76 and love the results but it is a bit to close to the "edge" for the left side of my brain to compr .......
167: Tube DIY Asylum, RE: LCR Phono stage (0.00)
Posted by dave slagle on 2021-04-30, 06:15:56 (67.189.163.37)
the subject at hand was a mosfet follower driving a low impedance load and I listed my only experience with them. The load was not difficult and yet they still left me wanting and sounded better witho .......
168: Tube DIY Asylum, RE: LCR Phono stage (0.00)
Posted by dave slagle on 2021-04-30, 04:21:30 (67.189.163.37)
I haven't tried the a mosfet follower to specifically drive a 600Ω LCR but have heard several variations at the input of an autoformer volume control in an attempt to buffer it. The results were simil .......
169: Tube DIY Asylum, RE: LCR Phono stage (0.00)
Posted by dave slagle on 2021-04-29, 05:25:48 (67.189.163.37)
Hey, This enters the "slippery slope" area that often derails audio. A mofset follower absolutely will work and the measured results will be nearly "ideal". Since we all know "perfect" devices do not .......
170: Tube DIY Asylum, RE: LCR Phono stage (0.00)
Posted by dave slagle on 2021-04-28, 16:42:09 (67.189.163.37)
in my view the achilles heel of all of this is finding a good sounding way to drive 600Ω. Thus far I have not found a way to do it that I want to listen to for more than 15 minutes. dave .......
171: Tube DIY Asylum, RE: LCR Phono stage (0.00)
Posted by dave slagle on 2021-04-28, 09:03:58 (67.189.163.37)
CCS for the cathode follower? Like the Allen Wright SLCF? dave .......
172: Tube DIY Asylum, RE: LCR Phono stage (0.00)
Posted by dave slagle on 2021-04-26, 06:29:54 (67.189.163.37)
Hey Paul, Both S&B and Silk made/make 10K modules and while the concept of high impedance is a good one. the use of a 10K number is misguided since it requires obscure cap values. Since the chokes wil .......
173: Tube DIY Asylum, RE: LCR Phono stage (0.00)
Posted by dave slagle on 2021-04-25, 16:44:18 (67.189.163.37)
measured results in the frequency domain don't tell the whole story and they can easily be adjusted. The issue I see is the 600Ω impedance and driving it with a sonically benevolent circuit. The .......
174: Tube DIY Asylum, RE: LCR Phono stage (0.00)
Posted by dave slagle on 2021-04-25, 06:52:27 (67.189.163.37)
The Pultec type LCR is a 600Ω network that either needs to be driven from 600Ω or terminated with 600Ω to have the desired response. Since it is a type of T network, it has a nearly con .......
175: Tube DIY Asylum, RE: That's the same fomuula I use ... (0.00)
Posted by dave slagle on 2021-03-24, 07:21:35 (67.189.163.37)
I have yet to see a case where core losses have caused appreciable heating and have often mused that with superconductors (no copper heating) Lenz and Tesla would still be at the top of the power tran .......
176: Tube DIY Asylum, RE: " (edit... oops.. I see PJ said this above...)"... (0.00)
Posted by dave slagle on 2021-03-23, 11:43:47 (67.189.163.37)
sure.... the only thing you need to watch out for is heating and I doubt that will be a problem unless you are adding some 2.5V @ 18A windings for tungars :-) dave .......
177: Tube DIY Asylum, RE: Core Flux (0.00)
Posted by dave slagle on 2021-03-23, 09:18:50 (67.189.163.37)
Actually Lenz's law states that current delivered to the load does not add any flux to the core. The only place you can run into issues doing this is additional copper heating on the primary. dave (ed .......
178: Vinyl Asylum, RE: ever tried Moongel? (0.00)
Posted by dave slagle on 2021-03-21, 09:06:48 (67.189.163.37)
rumor has it that moongel is shockingly similar to Zerodust. dave .......
179: Tube DIY Asylum, RE: When modeling ultralinear a doubt arises.., (0.00)
Posted by dave slagle on 2021-03-20, 19:46:15 (67.189.163.37)
here are the values you need for a 20% tap assuming a 100hy end to end inductance. double all the numbers if you want 200hy end to end. if you want 43% L1/L4=4.623, L2/L4=8.123 dave .......
180: Vinyl Asylum, RE: Half Speed playback DIY? (0.00)
Posted by dave slagle on 2021-03-20, 08:46:43 (67.189.163.37)
Hey, I have really enjoyed this tangent and will follow inline. This was exactly my point in the other thread on the WallyTools zenith measurement service when I questioned the relevance of the serv .......
181: Tube DIY Asylum, RE: WE Harmonic Balancer (0.00)
Posted by dave slagle on 2021-03-19, 08:13:54 (67.189.163.37)
the link below has a stephie bench's take on the circuit. dave .......
182: Vinyl Asylum, RE: Half Speed playback DIY? (0.00)
Posted by dave slagle on 2021-03-19, 06:47:01 (67.189.163.37)
We are saying the same thing actually and I have also referred to the forces acting on a non-spherical tip which could contribute to mistracking. I see the same forces in effect on a spherical tip a .......
183: Vinyl Asylum, RE: Half Speed playback DIY? (0.00)
Posted by dave slagle on 2021-03-17, 20:23:41 (67.189.163.37)
I'll go a bit out of order on this... With a spherical stylus, the stylus contacts the same point in time on each wall that is always perpendicular to the direction of motion which matches the cutter .......
184: Tube DIY Asylum, RE: A 1962 B&O performer (0.00)
Posted by dave slagle on 2021-03-17, 13:48:52 (67.189.163.37)
WE used it in the 124 amps dave .......
185: Vinyl Asylum, RE: Half Speed playback DIY? (0.00)
Posted by dave slagle on 2021-03-17, 11:14:04 (67.189.163.37)
So in summary, yes, mistracking probably occurs more often than not, but not (in my opinion only) due to vinyl surface finish at a molecular level, but as a result of (again, in my opinion only) poor .......
186: SET Asylum, RE: Same Here (0.00)
Posted by dave slagle on 2021-03-17, 11:00:53 (67.189.163.37)
I was told that this new coating takes about 200 hours of use to sound its best. I have about 15 hours on them so far. so wait... these are not original 300b repros but "new and improved"? is there .......
187: Vinyl Asylum, RE: Half Speed playback DIY? (0.00)
Posted by dave slagle on 2021-03-16, 20:02:46 (67.189.163.37)
I think we are missing each other on this discussion.... let me ask it this way.... is all mistracking audible? This ends up being along the lines of the "If a tree falls in the woods" thought process .......
188: Vinyl Asylum, RE: Half Speed playback DIY? (0.00)
Posted by dave slagle on 2021-03-16, 06:27:44 (67.189.163.37)
Hey, the use of the term momentarily is way too ambiguous. How long is a moment? I guess it could be argued along the lines of nyquest that if that "moment" is 50µs or more then you have mistracking b .......
189: Tube DIY Asylum, RE: Well... (0.00)
Posted by dave slagle on 2021-03-15, 12:44:55 (67.189.163.37)
I am not trying to debate he merits of the SLCF but questioning the purpose of using one to drive ANOTHER cathode follower. dave .......
190: Tube DIY Asylum, RE: Well... (0.00)
Posted by dave slagle on 2021-03-15, 08:10:19 (67.189.163.37)
nobody seems to want to answer the 800 pound gorilla in the corner asking if this "CF" circuit to drive the grid of another CF is clever or redundant? dave .......
191: Vinyl Asylum, RE: Half Speed playback DIY? (0.00)
Posted by dave slagle on 2021-03-14, 08:26:06 (67.189.163.37)
I think this is a really interesting concept and if I were to digitize a collection I would look into it. Mistracking is the most ill defined term in audio and i would love to see a good technical def .......
192: Tube DIY Asylum, RE: class a2 on 805 has something to do with it..-nt (0.00)
Posted by dave slagle on 2021-03-13, 07:20:50 (67.189.163.37)
That is a current. It is the quickest way to check output impedance of a circuit. In the voltage sweeps you will see that V1 is set to AC1 or 1V which is 0dB so the readouts on the plot gives you the .......
193: Tube DIY Asylum, RE: class a2 on 805 has something to do with it..-nt (0.00)
Posted by dave slagle on 2021-03-13, 06:22:08 (67.189.163.37)
since nobody seems to have a strong opinion on what is going on here I went to spice. I first used a 6dJ8 and spice wouldn't run the circuit. I switched to a 5687 and things were better and the e88cc .......
194: Tube DIY Asylum, RE: class a2 on 805 has something to do with it..-nt (0.00)
Posted by dave slagle on 2021-03-11, 10:58:21 (67.189.163.37)
The grid of the A2 805 is what the 300B CF is there for. As far as I know the grid of a 300B CF doesn't require any heroic needs to drive it and cannot see a reason why the stage in question which fee .......
195: Tube DIY Asylum, RE: Super Linear Cathode Follower? (0.00)
Posted by dave slagle on 2021-03-11, 05:21:20 (67.189.163.37)
I am no JC Morrison or John Broskie when it comes to dissecting a circuit but I am always intrigued by something different. I am really still on the fence here as to whether this is truly a brilliant .......
196: Tube DIY Asylum, RE: Super Linear Cathode Follower? (0.00)
Posted by dave slagle on 2021-03-10, 18:31:33 (67.189.163.37)
I was always under the impression that the 300B cathode follower would be a relatively easy load to drive. Why drive a CF with a CF? dave .......
197: Tube DIY Asylum, RE: Super Linear Cathode Follower? (0.00)
Posted by dave slagle on 2021-03-10, 11:23:38 (67.189.163.37)
Hmmm... a SLCF to drive a 300B CF??? that would certainly be belt and suspenders. dave .......
198: Tube DIY Asylum, RE: Might these pics/schematics help? (0.00)
Posted by dave slagle on 2021-03-10, 05:01:12 (67.189.163.37)
OK... I'll bite the input / driver stage has me scratching my head. What is the stage that uses 3 6922's? kinda looks like s supertriode srpp if such a thing could be done. dave .......
199: Vinyl Asylum, RE: While on the subject of 'step up transformers'... (0.00)
Posted by dave slagle on 2021-03-02, 05:10:26 (67.189.163.37)
There are a lot of different ROT's out there for selecting a SUT and most of them are short sighted and only take into consideration one aspect of the process. If you deem the maximum source:load impe .......
200: Tube DIY Asylum, RE: Jupiter Copper Foil Beewax Cap (0.00)
Posted by dave slagle on 2021-02-25, 06:25:08 (67.189.163.37)
Hey, On the rare occasion i use coupling / filter capacitors the Jupiter Copper foils are my go to part. I find them to be the most musical sounding capacitor available. Back when I used capacitors in .......
201: Tube DIY Asylum, RE: "Grid Leak Resistor" (0.00)
Posted by dave slagle on 2021-02-21, 17:44:17 (67.189.163.37)
The resistors are there to prevent blocking distortion and not oscillation. We are not talking 417A's or 6C45's here...It would take a pretty miserably laid out output stage to actually get a 300B .......
202: Tube DIY Asylum, RE: "Grid Leak Resistor" (0.00)
Posted by dave slagle on 2021-02-21, 06:06:00 (67.189.163.37)
And while we are at it....incorrectly calling the large value (1-10K) series resistor to the grids of class AB PP outputs a grid stopper. dave .......
203: Tubes Asylum, RE: 811 and 300B TUBE SOCKET PATTERNS (0.00)
Posted by dave slagle on 2021-02-20, 05:46:39 (67.189.163.37)
I have had that happen with some chinese octal johnson clones. a few things to check. how long are the pins of the tubes in question compared to a 4 pin tube that seats properly? Do the bottom of the .......
204: Tube DIY Asylum, RE: Question about power transformer rating with LC choke and others (0.00)
Posted by dave slagle on 2021-02-14, 06:14:32 (67.189.163.37)
the simple math. choke input gives you 0.9X secondary RMS so 475 * 0.9= 427. Then subtract your schottky drop ~2V for 425 then subtract the multiplied value of the current draw and the choke DCR's ass .......
205: Vinyl Asylum, RE: Fremer's ZENITH ANGLE CORRECTION or have we all gone crazy. (0.00)
Posted by dave slagle on 2021-02-11, 09:59:51 (67.189.163.37)
My take thus far on this is quite different and only a hypothesis at this point so apply salt to what follows. I suspect that the idea that incorrect zenith simply effects phase is flawed. The Electro .......
206: Vinyl Asylum, RE: Fremer's ZENITH ANGLE CORRECTION or have we all gone crazy. (0.00)
Posted by dave slagle on 2021-02-10, 07:48:27 (67.189.163.37)
Anthony, you bring up a bunch of great points, I'd like to dig deeper into the one below. it is more important that the coils/motor be aligned for minimum tangential error to the groove rather than i .......
207: Tubes Asylum, RE: Western Electric vintage video: tube tech 1940 (0.00)
Posted by dave slagle on 2021-02-08, 07:16:07 (67.189.163.37)
I found it surprising that this was the first representation of almost a "google" that I recall seeing. The went old school and said 10 followed by 99 zeros rather than going for the full hundred. :: .......
208: Vinyl Asylum, RE: The reason I asked about the Cartridge.... (0.00)
Posted by dave slagle on 2021-01-26, 06:35:31 (67.189.163.37)
John, Do you know if the readings of the Fozgo are the actual values of the crosstalk in dB or just relative numbers? The numbers I tend to see from the published reading always seem overly optimistic .......
209: Tubes Asylum, RE: Output transformer/speaker load and active biamping (0.00)
Posted by dave slagle on 2021-01-25, 06:59:55 (67.189.163.37)
Moving to tube power amps, will the amps directly connected to the tweeter/woofer panels be ok and present the proper speaker load to protect the tubes and output transformer? in general, the questi .......
210: Vinyl Asylum, RE: An interesting look at radical stylus profiles. Link. (0.00)
Posted by dave slagle on 2021-01-13, 06:41:29 (67.189.163.37)
My guess is the biggest place for error in the test setup is Zenith of the diamond. With the advanced profiles, even a 30' variance in diamond set can have a profound sonic effect. dave .......
211: Tube DIY Asylum, RE: Yup. nt (0.00)
Posted by dave slagle on 2021-01-05, 06:44:11 (67.189.163.37)
I think the issue here comes down to grey area and definitions. I know tre' has a definition of "Class A" which essentially boils down to tubes run in the "most linear region" opposed to the more trad .......
212: Tube DIY Asylum, RE: and yet... (0.00)
Posted by dave slagle on 2021-01-04, 17:58:59 (67.189.163.37)
Not sure about who is currently making class A PP ams but I do recall Allen Wright offering some PP 300B amps with his "black box bias" for the finals which essentially was a CCS. This would by defini .......
213: Tube DIY Asylum, RE: Basic Drive Voltage Question (0.00)
Posted by dave slagle on 2020-12-14, 06:01:40 (67.189.163.37)
above you said. iThe quality is not what i want and it also has a resonance problem at low frequencies. No issues with you not liking the sound of choke loading. That is subjective and completely un .......
214: Tube DIY Asylum, RE: Basic Drive Voltage Question (0.00)
Posted by dave slagle on 2020-12-13, 11:25:13 (67.189.163.37)
you are confusing/combining loading with coupling. granted an IT handles both at the same time but from a loading of a triode perspective both chokes and transformers show the same behavior and can b .......
215: Tube DIY Asylum, RE: Basic Drive Voltage Question (0.00)
Posted by dave slagle on 2020-12-13, 05:48:50 (67.189.163.37)
of course.... but alas I find many of the tubes with great specifications for transformer / inductor usage are sonically the last tube I want to use for long term enjoyment. I would love a DHT with th .......
216: SET Asylum, RE: Serious Stereo ... KT150 (0.00)
Posted by dave slagle on 2020-12-12, 06:02:00 (67.189.163.37)
are the 6E6 and KY-150 triode connected? dave .......
217: Tube DIY Asylum, RE: Basic Drive Voltage Question (0.00)
Posted by dave slagle on 2020-12-11, 07:17:30 (67.189.163.37)
choke should be 5x plate resistance at lowest frequency of interest, the highs are inherently taken care of. I have minor quibbles with both the low frequency and high frequency aspects of this state .......
218: Vinyl Asylum, RE: What about this low mass tonearm? (0.00)
Posted by dave slagle on 2020-12-05, 15:10:13 (67.189.163.37)
the air bearing part could be in error but what does the "3 fulcrums" refer to? dave .......
219: High Efficiency Speaker Asylum, RE: Adding a digital component.. (0.00)
Posted by dave slagle on 2020-12-05, 13:58:54 (67.189.163.37)
the missing (more frequent??) option here is a speaker that measures good and sounds bad. dave .......
220: Vinyl Asylum, RE: What about this low mass tonearm? (0.00)
Posted by dave slagle on 2020-12-05, 08:58:59 (67.189.163.37)
Is it possible to have an air bearing without an external air source? dave .......
221: Tube DIY Asylum, RE: Another Source for Aluminum Chassis (0.00)
Posted by dave slagle on 2020-12-04, 17:54:23 (67.189.163.37)
Al Bryant was all over that back in 1995 courtesy of Sound Practices #11 .......
222: High Efficiency Speaker Asylum, RE: Adding a digital component.. (0.00)
Posted by dave slagle on 2020-11-30, 12:56:42 (24.179.107.188)
I was referring to the filter at the output of a Dac. dave .......
223: High Efficiency Speaker Asylum, RE: Adding a digital component.. (0.00)
Posted by dave slagle on 2020-11-30, 10:13:14 (24.179.107.188)
I'll side with ivan and believe no matter how many A/D >> D/A conversion there have been in the manufacture of my vinyl, adding another one after the fact cannot be considered benign. In the small amo .......
224: High Efficiency Speaker Asylum, RE: Adding a digital component.. (0.00)
Posted by dave slagle on 2020-11-30, 07:46:09 (24.179.107.188)
if you follow nyquest and say that all that is needed for reproduction is a sampling rate of 2X the highest frequency to be reproduced then what is the point of going to 96, 192 or 384K for sampling r .......
225: High Efficiency Speaker Asylum, RE: That's a pretty bold statement... (0.00)
Posted by dave slagle on 2020-11-27, 11:38:28 (67.189.163.37)
I agree with you that converting analog to low sample rate digital for crossover work is a slippery slope. The one thing that has pushed a few of my friends down that slope is the ability to time alig .......
226: High Efficiency Speaker Asylum, RE: Adding a digital component.. (0.00)
Posted by dave slagle on 2020-11-27, 06:54:23 (67.189.163.37)
Am I correct in reading the specifications that the PA2 does the A/D @ 48kHz and the DEQX is 96K 24bit. Also how does the PA2 differ from the Behringer Ultracurve? dave .......
227: High Efficiency Speaker Asylum, RE: If it is high level HD..... (0.00)
Posted by dave slagle on 2020-11-21, 06:09:52 (67.189.163.37)
The cone offset is a casual curiosity to me. years ago I was using lowthers and while many insisted they were underhung I found many to actually be "even hung" where the length of the voice coil equal .......
228: Tube DIY Asylum, RE: Yes, that kind of HF drop is very common. (0.00)
Posted by dave slagle on 2020-11-20, 20:12:49 (67.189.163.37)
OK... what high frequency dip am I missing? I see a 4dB fairly low Q resonant peak @ ~80kHz in the 47K situation and a rising response that is a little more than +6dB @ 100Khz. The general pattern of .......
229: Tube DIY Asylum, RE: Another 5842 question, grid and cathode (0.00)
Posted by dave slagle on 2020-11-15, 08:06:41 (67.189.163.37)
This isn't really about the "right" way to do it but possible reasons to why it was done. I think the important thing to realize when looking at existing PP designs is that resistors in line with the .......
230: Tube DIY Asylum, RE: Another 5842 question, grid and cathode (0.00)
Posted by dave slagle on 2020-11-14, 09:46:43 (67.189.163.37)
The high value "grid stopper" seen at the output tubes in pp amps is not there to prevent oscillation but to reduce blocking distortion as you said in #3 above. Whether or not it is a valid / relevant .......
231: Vinyl Asylum, RE: Cinemag 1254 SUT (0.00)
Posted by dave slagle on 2020-11-13, 15:28:59 (67.189.163.37)
Just make sure whatever you get has the 1:10 option for the Zephyr MIMC. If possible also take the input resistor of your phono up to 100K. dave .......
232: Vinyl Asylum, RE: Best loading for a Zephyr MiMC (0.00)
Posted by dave slagle on 2020-11-11, 06:38:34 (67.189.163.37)
The specifications say ≥470Ω which is quite different than "use 470Ω". The 470 value represents the maximum (smallest value) load that is suggested and it happens to align exactly w .......
233: Vinyl Asylum, RE: Best loading for a Zephyr MiMC (0.00)
Posted by dave slagle on 2020-11-10, 07:48:06 (67.189.163.37)
I am aware of Jim's work on this topic. This does not change my belief that a 10dB resonant peak @ 30kHz should be not viewed in the same manner as a 10dB peak @ 200kHz or a 10dB peak @ 2mHz. dave ::: .......
234: Vinyl Asylum, RE: Best loading for a Zephyr MiMC (0.00)
Posted by dave slagle on 2020-11-10, 06:01:34 (67.189.163.37)
Your graphs bring up the interesting relationship between loading and phase. By loading to fix issues in the amplitude domain you have a negative impact on the time domain. From a technical POV I see .......
235: Vinyl Asylum, RE: Best loading for a Zephyr MiMC (0.00)
Posted by dave slagle on 2020-11-09, 15:02:33 (67.189.163.37)
I think the maximum load is listed at 470Ω but you want to go much higher in value than that. Based on the 2.75mHy of coil inductance a 470Ω load will give a -3dB point of 27.2kHz which puts .......
236: Vinyl Asylum, RE: Too much information (0.00)
Posted by dave slagle on 2020-11-07, 05:50:30 (67.189.163.37)
Hey Lew, You know way more about EM's than I. I googled a bit about the depth of field and it said distances of a few mm were possible which is huge. I was going more from the animation that was float .......
237: Vinyl Asylum, RE: Too much information (0.00)
Posted by dave slagle on 2020-11-06, 05:58:27 (67.189.163.37)
depth of field is inversely proportional to magnification and to inspect the tracing faces you need a lot more magnification than shown in the pictures you posted. dave .......
238: Vinyl Asylum, RE: Too much information (0.00)
Posted by dave slagle on 2020-11-05, 16:45:53 (67.189.163.37)
the problem with standard microscope views is the limited focus range (depth of field) so you cannot see the entire surface of the contour at one time. To inspect a stylus tou keep shifting focus and .......
239: Tube DIY Asylum, RE: Have you ever pushed a 2A3 to 20W dissipation? (nt) (0.00)
Posted by dave slagle on 2020-10-26, 05:07:42 (67.189.163.37)
Back in the day routinely. The general consensus at the time was the vintage tubes could easily handle it and the chinese tubes were only $5 so who cares. dave .......
240: Tube DIY Asylum, RE: How rugged are vintage 2A3 tubes? (0.00)
Posted by dave slagle on 2020-10-24, 06:31:31 (67.189.163.37)
What follows is some folklore surrounding the 2A3. I am not sure of the exact chronology of the biplate versions so I will present them in the order that makes the most sense (vintage 2A3 pictures fro .......
241: High Efficiency Speaker Asylum, RE: Will likely give Dave a shout... (0.00)
Posted by dave slagle on 2020-10-19, 08:57:36 (67.189.163.37)
Since Mats opened the door.... a good description of the speakerformers is linked below. Along with adjusting level and allowing the driver impedance to be selected, the driver impedance can also be v .......
242: Tube DIY Asylum, RE: What makes a high quality plate choke? .... Better yet .... (0.00)
Posted by dave slagle on 2020-10-17, 06:30:34 (67.189.163.37)
I think the blurb by Joseph above comparing what I did for him to replace the James transformers is interesting. He approached me to wind some chokes because the James he was using were no longer avai .......
243: Tube DIY Asylum, RE: What makes a high quality plate choke? .... Better yet .... (0.00)
Posted by dave slagle on 2020-10-15, 06:30:23 (67.189.163.37)
"What would winding towards the same electrical characteristics on different cores tell me?" I believe there are certain primary design considerations that must be met for all transformers and they .......
244: Tube DIY Asylum, RE: So there Dave... (0.00)
Posted by dave slagle on 2020-10-14, 07:41:37 (67.189.163.37)
the high temperature wire insulations. From the color of the insulation it looks to be polymide but it could be another polyester based type. .......
245: Tube DIY Asylum, RE: So there Dave... (0.00)
Posted by dave slagle on 2020-10-14, 05:58:26 (67.189.163.37)
that suggests 10pf of capacitance which represents a srf of around 14Khz. curious as to why you used the poylmide / ML insulated wire? Is it a sonic choice or what you had on hand? dave .......
246: Tube DIY Asylum, RE: So there Dave... (0.00)
Posted by dave slagle on 2020-10-14, 05:49:45 (67.189.163.37)
I think by definition the self resonance you talk of always needs to be midband. It is the resonance of the two things that limit frequency extremes and typically falls in the 500Hz-2kHz range. This m .......
247: Tube DIY Asylum, RE: What makes a high quality plate choke? .... Better yet .... (0.00)
Posted by dave slagle on 2020-10-13, 17:04:22 (67.189.163.37)
I have yet to see complete data of core behavior below 1 gauss.... oops sorry 1µT. I'm sure Elmen and later Yensen documented it for the nickels but that info is locked away in the bell labs archives .......
248: Tube DIY Asylum, RE: What makes a high quality plate choke? .... Better yet .... (0.00)
Posted by dave slagle on 2020-10-13, 11:44:03 (67.189.163.37)
In the case of the JLSEM data I know that straight line ultimately bends when you extend it on both directions. For all cores this low level behavior is both non-linear and under-documented. It genera .......
249: Tube DIY Asylum, RE: What makes a high quality plate choke? .... Better yet .... (0.00)
Posted by dave slagle on 2020-10-13, 08:41:52 (67.189.163.37)
Tesla Mode On what is rubbish is assailing a clearly stated opinion with dubious facts. we went over this a month ago where I asked for low flux (µT levels) loss data and asked for more than just yo .......
250: Tube DIY Asylum, RE: What makes a high quality plate choke? .... Better yet .... (0.00)
Posted by dave slagle on 2020-10-13, 05:59:09 (67.189.163.37)
I make decisions based on what I hear then look to find the appropriate facts to explain it. I also 'gasp' use single ended directly heated triodes because they sound better and i'm sure physics can p .......
251: Tube DIY Asylum, RE: What makes a high quality plate choke? .... Better yet .... (0.00)
Posted by dave slagle on 2020-10-12, 07:13:02 (67.189.163.37)
I think I clearly stated that my preference for nickel was my opinion based on listening experience and direct comparisons between the various material in identical designs. I didn't simply buy a nick .......
252: Tube DIY Asylum, RE: What makes a high quality plate choke? .... Better yet .... (0.00)
Posted by dave slagle on 2020-10-11, 13:36:43 (67.189.163.37)
If nickel gives a colored sound (whatever that is) then I am fine with it. I'll take better sound over better material specifications any day. It is pretty easy to have a preference and then find spec .......
253: Vinyl Asylum, RE: Yet another sut situation (0.00)
Posted by dave slagle on 2020-10-09, 05:55:42 (67.189.163.37)
There are two things to consider when mating a cartridge to a SUT. -The cartridge internal impedance. This lets the winder set the balance between the desired low frequency extension and the high freq .......
254: Tube DIY Asylum, RE: What makes a high quality plate choke? .... Better yet .... (0.00)
Posted by dave slagle on 2020-10-08, 08:17:32 (67.189.163.37)
Well without getting into specsmanship of the various core materials and topologies I can offer up my opinion. This is based primarily on the sonics of direct comparisons with nickel, nanocrystalline, .......
255: Tube DIY Asylum, RE: What makes a high quality plate choke? .... Better yet .... (0.00)
Posted by dave slagle on 2020-10-08, 06:06:08 (67.189.163.37)
There was a momentary trend when the 6C45pi came on the scene as a WE 437A replacement some 15-20 years ago to use it with a pretty heavy resistive load at currents below 10ma to get maximum "undistor .......
256: Tube DIY Asylum, RE: CCS Current Set Question (0.00)
Posted by dave slagle on 2020-09-17, 11:47:03 (67.189.163.37)
He has gotten 60dB of gain out of a single stage so I'd wager pentode :-) dave .......
257: Tube DIY Asylum, RE: Wow - that's a serious supply! (0.00)
Posted by dave slagle on 2020-09-16, 04:59:54 (67.189.163.37)
I have spent a fair bit of time tracking down the last bit of hum in an amp only to find it was from the AC heaters of the driver tube. Tried floating grounding elevating and every other trick to no a .......
258: Tube DIY Asylum, RE: CCS Current Set Question (0.00)
Posted by dave slagle on 2020-09-16, 04:56:50 (67.189.163.37)
That's why you usually don't see CS loads on pentodes. not that i condone such behavior but try telling that to JC :-) dave .......
259: Tube DIY Asylum, RE: How big a choke.... (0.00)
Posted by dave slagle on 2020-08-28, 06:46:19 (67.189.163.37)
Since we are traveling down memory lane I remember when PJ (or was it doc B?) suggested this approach many years ago and I gave it a spin. I was surprised what a nice clean sine wave this gave and wan .......
260: Tube DIY Asylum, Stephie Bench LT spice reactive loadlines. (0.00)
Posted by dave slagle on 2020-08-02, 12:41:34 (67.189.165.218)
Hey all you LTspicers... Stephie Bench did an incredible simulation program for just about every loadline you could imagine. Triode, Pentode, UL.... SE, PP with composite curves you name it. The l .......
261: Tube DIY Asylum, RE: the new breadboard is earning its keep (0.00)
Posted by dave slagle on 2020-08-02, 11:17:04 (67.189.165.218)
Yeah... saw it. the second stage isn't technically a grounded grid is it? The 100K / 20K voltage divider from the output applies feedback to the grid. Looks to me like a differential phase splitter wi .......
262: Tube DIY Asylum, RE: the new breadboard is earning its keep (0.00)
Posted by dave slagle on 2020-08-01, 04:40:11 (67.189.165.218)
as an aside on this... how does the transcendent grounded grid pre obtain its published 50K input Z? dave .......
263: Tube DIY Asylum, RE: I think you're right. (0.00)
Posted by dave slagle on 2020-07-31, 16:35:25 (67.189.165.218)
agreed... not a waste of space at all! Not sure what you mean by the low side, but the generally accepted orientation is to have the outer foil at the node with the lowest impedance to ground. This me .......
264: Tube DIY Asylum, RE: the new breadboard is earning its keep (0.00)
Posted by dave slagle on 2020-07-31, 05:30:17 (67.189.165.218)
One other thing that is important to remember about grounded grid (cathode drive) circuits is that the input impedance is quite low so they can be rather difficult to drive. The input impedance is the .......
265: Tubes Asylum, RE: re question: Purpose of the mercury (0.00)
Posted by dave slagle on 2020-07-24, 05:15:15 (67.189.165.218)
That tube is an ignition and it is essentially a cold cathode high current relay that can switch hundreds to thousands of amps of current. The cathode sits in a pool of mercury and the anode is situat .......
266: Tube DIY Asylum, RE: Why nickel? (0.00)
Posted by dave slagle on 2020-07-11, 07:18:09 (67.189.165.218)
well... the 310 has no business driving a 300B so I concur with Pieter :-) as for the LF response... the 94µ cap is set resonate with the 36hy to extend the LF response corner. Not ideal but all of th .......
267: Vinyl Asylum, RE: Well, according to a well known lab coat scientist . . . (0.00)
Posted by dave slagle on 2020-07-11, 06:02:53 (67.189.165.218)
I'd like to see the data showing the difference in effectiveness between 35kHz and 40kHz. In the article linked below the author suggests that 35-40kHz is good for removing large particles and 80-120k .......
268: Tube DIY Asylum, RE: Why nickel? (0.00)
Posted by dave slagle on 2020-07-11, 05:35:36 (67.189.165.218)
I think "destroy" is a bit overly dramatic. Jean-Michel published the test rig measurement response right next to the drawing and -1dB @ 4Hz isn't a decade below the audio band but it is close. If .......
269: SET Asylum, RE: I have a very early version of the 2.5V TJ Mesh Plate (perferations, not real mesh)... (0.00)
Posted by dave slagle on 2020-07-10, 17:33:22 (67.189.165.218)
I find it hard to believe that firmly fixing the structure to the top of the envelope as well as the bottom helps isolate it from outside vibration. If anything, I would expect it to push the resonant .......
270: Tube DIY Asylum, RE: Why nickel? (0.00)
Posted by dave slagle on 2020-07-10, 15:36:22 (67.189.165.218)
ideally a CCS should be used in place of the choke but beyond that it looks like the correct setup. what problem do you see? dave .......
271: Tube DIY Asylum, RE: Why nickel? (0.00)
Posted by dave slagle on 2020-07-10, 12:58:32 (67.189.165.218)
why is the choke in the wrong place? if you have 70ma through a 10K resistor you will have a 700VDC drop. I would say that the tango connection is the incorrect one. .......
272: Tube DIY Asylum, RE: Why nickel? (0.00)
Posted by dave slagle on 2020-07-10, 12:11:09 (67.189.165.218)
b) the 3rd harmonic dominates and thus sets the THD figure. IF the distortion measurements were done with the test setup shown and a 70ma DC bias, I do not see how the third order harmonics could dom .......
273: Tube DIY Asylum, RE: Why nickel? (0.00)
Posted by dave slagle on 2020-07-10, 08:23:14 (67.189.165.218)
shooting rockets to the moon is fine and I could see why it is important to look at core losses at points well beyond the audio band. For audio these plots are looking at the wrong end of the flux spe .......
274: Tube DIY Asylum, RE: Sorry Folks (0.00)
Posted by dave slagle on 2020-07-10, 07:47:01 (67.189.165.218)
I agree 100% with you. My approach is: 1. use engineering to assure proper function for a basic starting point. 2. listen and see if your toes tap. 3. Look at the objective info to explain your toes b .......
275: SET Asylum, RE: Who makes that tube? (0.00)
Posted by dave slagle on 2020-07-08, 16:56:54 (67.189.165.218)
Interesting... the ebay ones show the tube to have an round top mica support with another "Trimmed on the side" round support above it extending beyond to the tube glass. This looks identical t .......
276: SET Asylum, RE: Who makes that tube? (0.00)
Posted by dave slagle on 2020-07-08, 05:32:19 (67.189.165.218)
The first picture in that article immediately actually struck my interest since the top mica support does not come in contact with the envelope. further down in the article there is a seemingly ide .......
277: Vinyl Asylum, RE: Cartridge alignment and tonearm design (0.00)
Posted by dave slagle on 2020-07-07, 16:02:58 (67.189.165.218)
thanks... kinda got it figured. I was confused by the different info in the R3-S3... your plots have distortion and mine have measurments. .......
278: Vinyl Asylum, RE: Cartridge alignment and tonearm design (0.00)
Posted by dave slagle on 2020-07-07, 12:05:40 (67.189.165.218)
Hey John, I downloaded the version from ETM and cell B3 simply say =o3 and a number of things appear different. is there a link to your current version? dave .......
279: Vinyl Asylum, RE: Cartridge alignment and tonearm design (0.00)
Posted by dave slagle on 2020-07-07, 10:53:29 (67.189.165.218)
Most of the discussions about the differences between Baerwald/Lofgren A, Lofgren B and Stevenson seem to indicate that all three can be successfully implemented without regard for the tonearm bei .......
280: Tube DIY Asylum, RE: Why nickel? (0.00)
Posted by dave slagle on 2020-07-07, 06:46:21 (67.189.165.218)
Guess where the supermalloy would be in this graph Pretty much in line with where the finemet is... I took the info from the curves I posted above and replotted it on your graph. Based on this gr .......
281: Tube DIY Asylum, RE: Why nickel? (0.00)
Posted by dave slagle on 2020-07-06, 14:19:40 (67.189.165.218)
The black line is simply interpolated. Assuming a constant voltage of 1V gives a flux of 150 gauss @ 100Khz that same 1V @ 50kHz will be 300 gauss and 3000 gauss at 5Khz. going down to 50hz would net .......
282: Tube DIY Asylum, RE: Why nickel? (0.00)
Posted by dave slagle on 2020-07-06, 07:04:35 (67.189.165.218)
The test conditions are not given. These graphs are intended for power and pulse use at a single frequency so I would guess they would be for a constant flux which is not representative of what happe .......
283: Tube DIY Asylum, RE: Why nickel? (0.00)
Posted by dave slagle on 2020-07-05, 17:56:39 (67.189.165.218)
I never said 80% could handle 15000g. I said "In a design where a dynamic peak hits 15,000g @ 100Hz" . For 80% simply divide the numbers by 3 and get 5000g and 5g. The point was to illustrate how low .......
284: Tube DIY Asylum, RE: Why nickel? (0.00)
Posted by dave slagle on 2020-07-05, 14:16:40 (67.189.165.218)
if folks want to have 'fun' on this subject I would like to see the citations and measurements underlying their opinions rather than subjective declaration. If you want wild ass speculation I'd have .......
285: Tube DIY Asylum, RE: Why nickel? (0.00)
Posted by dave slagle on 2020-07-05, 10:53:46 (67.189.165.218)
There you go with the word "better" again. Nanaocrystalline has a Bsat in between 49% and 80% nickel. How does that fit into your "all magnetic parameters of nickel cores are worse than nanocrystallin .......
286: Tube DIY Asylum, RE: Why nickel? (0.00)
Posted by dave slagle on 2020-07-05, 10:25:52 (67.189.165.218)
The thing about subjective responses is that we are all different; we hear and/or care about different things, so they don't match measurements consistently. This needs to be repeated.... well said .......
287: Tube DIY Asylum, RE: Why nickel? (0.00)
Posted by dave slagle on 2020-07-05, 07:29:56 (67.189.165.218)
Although the modern materials are better nickel is still a very good material can you please explain what your definition of "better" is? Silver has less resistance than copper, does that explain wh .......
288: Tube DIY Asylum, RE: Question about OPTs for SET (0.00)
Posted by dave slagle on 2020-07-05, 07:12:42 (67.189.165.218)
IF the reflected load does not appear in parallel for the calculation of F3 as you suggest then the F3 will remain unchanged independent of the secondary terminating value. Below is the plot of a 300B .......
289: Tube DIY Asylum, RE: Question about OPTs for SET (0.00)
Posted by dave slagle on 2020-07-04, 12:50:21 (67.189.165.218)
Are you sure about the right formula? reasonably... it make a few assumptions but gives a good representation... what formula do you use? measurements dosn't match with your calculation methode fr .......
290: Tube DIY Asylum, RE: Why nickel? (0.00)
Posted by dave slagle on 2020-07-04, 12:46:42 (67.189.165.218)
Its all about physics and making personal choices. The physics is objective.... personal choice subjective. It is clear that we have different subjective preferences and I clearly stated at the outs .......
291: Tube DIY Asylum, RE: Why nickel? (0.00)
Posted by dave slagle on 2020-07-04, 09:29:17 (67.189.165.218)
Having designed and listened to apples to apples comparisons between 80% nickel, 49% nickel, Finemet, amorphous, Cobalt and GOSS, I'll trust my ears and place them in the order listed. I find transfor .......
292: Tube DIY Asylum, RE: Why nickel? (0.00)
Posted by dave slagle on 2020-07-04, 06:13:18 (67.189.165.218)
With all due respect.... The belief that nickel cannot handle DC is pure hogwash. I find it excels in situations with standing DC and this includes the last power supply choke of a filter chain. dave .......
293: Tube DIY Asylum, RE: Why nickel? (0.00)
Posted by dave slagle on 2020-07-04, 06:11:14 (67.189.165.218)
But why nickel over the currently available alternatives? I'll field this one.... nickel sounds better :-) I have wound and listened to all of the various core materials in numerous different applic .......
294: Tube DIY Asylum, RE: Question about OPTs for SET (0.00)
Posted by dave slagle on 2020-07-01, 17:05:42 (67.189.165.218)
ahhh... makes perfect sense if you are considering two distinctly different devices and not reflecting a different load by altering the secondary impedance. thanks dave .......
295: Tube DIY Asylum, RE: share cad files? (0.00)
Posted by dave slagle on 2020-07-01, 09:28:55 (67.189.165.218)
download autodesk fusion 360. They currently give a free license to hobbyists and startups and it will let you draw to your hearts content. Lots of tutorials are out there to get you started. dave .......
296: Tube DIY Asylum, RE: Question about OPTs for SET (0.00)
Posted by dave slagle on 2020-07-01, 08:37:18 (67.189.165.218)
Hey paul, Operating at a reflected load of 5K compared to 2.5K will lose an octave of bass I think we have had this discussion before and I still don't see this to be true. The two things that deter .......
297: High Efficiency Speaker Asylum, RE: What's up with the random holes in the back (0.00)
Posted by dave slagle on 2020-06-26, 05:47:48 (67.189.165.218)
Looks like a 4 bolt pattern and a 6 bolt pattern for mounting two different drivers. There are also a pair of adapters for a 2" compression driver included so one of the patterns may be for connecting .......
298: Vinyl Asylum, RE: Went back and re-read it, what he's on about is about $375.00 (0.00)
Posted by dave slagle on 2020-06-21, 14:20:00 (67.189.165.218)
that is probably the pressing by Pete Hutchison of the Electric Recording Co. I had an early Lacquer of the mono pressing at the Capital Audiofest last november and I can't wait to hear his final mono .......
299: High Efficiency Speaker Asylum, RE: Western electric driver clones (0.00)
Posted by dave slagle on 2020-05-20, 06:38:06 (67.189.165.218)
it is currently available at the link below. .......
300: Vinyl Asylum, RE: Cartridge loading with a potentiometer (0.00)
Posted by dave slagle on 2020-05-17, 08:19:53 (67.189.165.218)
Capacitance is something that needs to be taken into consideration for MM/MC's In my experience, capacitance needs to be tuned for MM and that values typically used for MM's have almost zero effect .......
301: Vinyl Asylum, RE: Cartridge loading with a potentiometer (0.00)
Posted by dave slagle on 2020-05-17, 07:42:29 (67.189.165.218)
Sure.... why not? by all accounts any compromises to the sound added by the pot will remain consistent over the span of values in question. This serves as a teaching tool allowing you to quickly expl .......
302: Vinyl Asylum, RE: Cartridge loading with a potentiometer (0.00)
Posted by dave slagle on 2020-05-17, 07:23:53 (67.189.165.218)
Hey, MM and MC are very different animals when it comes to loading, Based on listening experience, what you say matches my experience for MM carts but does not hold true for MC carts. From a Technical .......
303: High Efficiency Speaker Asylum, RE: Western electric driver clones (0.00)
Posted by dave slagle on 2020-05-12, 05:42:15 (67.189.165.218)
I think this take on the subject is reminiscent of the introduction of solid state devices as a technologically superior alternative to tubes and Redbook CD as the replacement of the LP. Just because .......
304: Tube DIY Asylum, RE: RCA 816 MV (0.00)
Posted by dave slagle on 2020-05-12, 05:05:09 (67.189.165.218)
This blurb is interesting at the end of the data sheet. Not sure exactly how to interpret it but it does seem to suggest exactly the opposite of what everyone else says about MV tubes. In this case it .......
305: Tube DIY Asylum, RE: Beauties indeed. Do the come in PCB mount? (nt) (0.00)
Posted by dave slagle on 2020-04-26, 17:35:14 (67.189.165.218)
They are PCB mount... dave .......
306: Tube DIY Asylum, RE: Source for BLACK 9 pin sockets PCB mount (0.00)
Posted by dave slagle on 2020-04-26, 10:49:16 (67.189.165.218)
the pictures are darker than the ones I have here which are a what I would call a dark chocolate brown. Pictures are a funny thing and here is the same socket on a light and dark background. ::: .......
307: Tube DIY Asylum, RE: Source for BLACK 9 pin sockets PCB mount (0.00)
Posted by dave slagle on 2020-04-26, 07:25:26 (67.189.165.218)
these are dark brown and have a nice finish / feel to them. .......
308: Vinyl Asylum, RE: Honest, Dave... (0.00)
Posted by dave slagle on 2020-04-23, 05:57:41 (67.189.165.218)
hey, for me this was mostly a gedanken exercise and I'll take empirical results any day! it does seem logical that a rinse would reduce the ratio of surfactant to water. The whole idea of forced air .......
309: Vinyl Asylum, RE: That quote is what i get with.... (0.00)
Posted by dave slagle on 2020-04-21, 18:16:49 (67.189.165.218)
I just see an odd paradox that the surfactant is the only way to get the US to clean the bottom of the groove but then what is supposed to get the surfactant out of the bottom of the groove. I like th .......
310: Vinyl Asylum, RE: Well it's not BS (0.00)
Posted by dave slagle on 2020-04-21, 06:18:50 (67.189.165.218)
What IS true is that if the surfactant solution is not properly rinsed off then you will hear lots of crackles - any contaminants from the fluid still remaining will be audible even if the grooves ar .......
311: Tube DIY Asylum, RE: I was thinking of placing a resistor to ground,... (0.00)
Posted by dave slagle on 2020-04-18, 05:59:11 (67.189.165.218)
it doesn't have to... here is a screen capture from the Broskie article I think Lew was referring to which is linked below. .......
312: Vinyl Asylum, RE: Yes, the Tsar DST is currently being produced..... (0.00)
Posted by dave slagle on 2020-04-15, 08:40:12 (67.189.165.218)
you are conflating two things here. I think the graph is the relevant one which represents the in system behavior. I agree if you put an impedance meter across a cartridge you will get results simila .......
313: Vinyl Asylum, RE: Dave, have you heard the ART1000? (0.00)
Posted by dave slagle on 2020-04-14, 14:23:43 (67.189.165.218)
No on the ART1000. I have heard the first version of the Tsar, an original DST and the Lumiere and there is a special quality to them all. dave .......
314: Vinyl Asylum, RE: Yes, the Tsar DST is currently being produced..... (0.00)
Posted by dave slagle on 2020-04-14, 14:17:15 (67.189.165.218)
your numbers appear to be off by a decade. to me your graph shows -2.3º of phase shift at 200KHz and 23º @ 2MHz. In either case (1µ or 10µ) the phase shift @ 20Khz is in the low milli-degrees and to g .......
315: Vinyl Asylum, RE: Yes, the Tsar DST is currently being produced..... (0.00)
Posted by dave slagle on 2020-04-14, 07:08:09 (67.189.165.218)
It's rated at 0.2-mV output voltage with only 3-ohms coil impedance and the lowest coil inductance I've ever heard of at just 1-microhenry. This is very important when it comes to frequency and phase .......
316: Tube DIY Asylum, RE: Need help selecting a 5.0volt D.C. module for 300B filament , (0.00)
Posted by dave slagle on 2020-04-10, 21:06:52 (67.189.165.218)
hey... don't get me wrong... I am a current source guy and the thought of a low impedance supply driving an input node of a circuit really bothers me. What everyone here seems to be missing is that th .......
317: Tube DIY Asylum, RE: Need help selecting a 5.0volt D.C. module for 300B filament , (0.00)
Posted by dave slagle on 2020-04-10, 17:27:53 (67.189.165.218)
I have heard a few people I trust say that the Mean Well converters work really well for DHT filaments. They used them for 845's but they make a 5V @ 8A version that takes line voltage in and outputs .......
318: Tube DIY Asylum, RE: anybody know the name of oil filled gold foil caps? (0.00)
Posted by dave slagle on 2020-04-03, 07:07:35 (67.189.165.218)
One point of note.... these are metallized film capacitors which use both silver and gold in the process of coating a substrate and quite different than caps that use actual foil of the same materials .......
319: Tube DIY Asylum, RE: Why low plate volt can have lower plate resistance (0.00)
Posted by dave slagle on 2020-04-01, 06:12:02 (67.189.165.218)
look at a set of plate curves. The rP is the slope of the curve through the bias point. For a given bias current as you move to higher anode voltage and grid bias values the slope of the curve gradual .......
320: Tube DIY Asylum, RE: SE IT, Flux reserved for AC and DC (0.00)
Posted by dave slagle on 2020-03-03, 06:39:47 (67.189.165.218)
Ahhh... primary inductance... measure it 5 different ways and you will get 5 different values.... all of them correct and dependent on excitation voltage and frequency. In the picture you attached the .......
321: Tube DIY Asylum, RE: SE IT, Flux reserved for AC and DC (0.00)
Posted by dave slagle on 2020-03-02, 10:21:32 (67.189.165.218)
well that is the $1,000,000 question. In a perfect world the answer is yes and every transformer would have DC to Light bandwidth. In reality it becomes a choice of compromise. Generally speaking, eve .......
322: SET Asylum, RE: The longest lasting Triode in the world (0.00)
Posted by dave slagle on 2020-03-02, 06:33:25 (67.189.165.218)
I know nothing of life testing and I'm sure there is a science to it to "speed up the process" but 1.6 million hours is 182 years..... dave .......
323: Tube DIY Asylum, RE: caps (0.00)
Posted by dave slagle on 2020-03-02, 06:16:58 (67.189.165.218)
really good point Lew. That cap works against the grid resistor which is typically not critical in value aside from its relationship to the cap so shifting down an octave by doubling the resistor val .......
324: Tube DIY Asylum, RE: SE IT, Flux reserved for AC and DC (0.00)
Posted by dave slagle on 2020-02-29, 09:05:40 (67.189.165.218)
your best bet is to build the circuit and measure the low frequency response and look for obvious distortion with the choke as is @ 30ma for a baseline. Then increase the current to 40ma and see how t .......
325: Tube DIY Asylum, RE: Wire gauges (0.00)
Posted by dave slagle on 2020-02-28, 06:47:30 (67.189.165.218)
Wire gauge has nothing to do with voltage and everything to do with current. The more current you run and the longer a run the thicker the wire you need. This essentially comes down to copper heating .......
326: Tube DIY Asylum, RE: High input or output impedance (0.00)
Posted by dave slagle on 2020-02-21, 16:32:40 (67.189.165.218)
200Hz at 40Hy at a 4k load .......
327: Tube DIY Asylum, RE: High input or output impedance (0.00)
Posted by dave slagle on 2020-02-21, 10:54:13 (67.189.165.218)
2A3 book points 40Hy @ 200hz green 2K5 load blue 1M load Green 25hy @ 1MΩ 200hz Blue 40hy @ 1MΩ 200hz .......
328: Tube DIY Asylum, RE: High input or output impedance (0.00)
Posted by dave slagle on 2020-02-21, 08:08:35 (67.189.165.218)
How else do you expect to get the beach ball volt sec showed? I'm not the one who made the beach ball a bad thing and I don't consider it a valid figure of merit. The only difference between a nice ti .......
329: Tube DIY Asylum, RE: High input or output impedance (0.00)
Posted by dave slagle on 2020-02-20, 20:19:27 (67.189.165.218)
don't understand what? dave .......
330: Tube DIY Asylum, RE: High input or output impedance (0.00)
Posted by dave slagle on 2020-02-20, 10:12:30 (67.189.165.218)
If we imagine the loadline to be placed on ideal equally spaced parallel tube 'lines' would there be any distortion? It is and has always been my contention that the width or ball like nature of the .......
331: Tube DIY Asylum, RE: ITC inductance question (0.00)
Posted by dave slagle on 2020-02-20, 09:39:53 (67.189.165.218)
The calculation for the -3dB point is the (Rp+DCR)||reflected load=2πFL. solving for F you get 2000||6000 or 1500/2π*36 which is 6.6hz This number assumes the tube can supply the current to .......
332: Tube DIY Asylum, RE: ITC inductance question (0.00)
Posted by dave slagle on 2020-02-19, 17:01:12 (67.189.165.218)
the -3db point is around 6hz for the output stage so the driver stage does appear to be the bottleneck. dropping the current to 32ma will take the Rp up a bit to say 1KΩ but the inductance you gain b .......
333: Tube DIY Asylum, RE: ITC inductance question (0.00)
Posted by dave slagle on 2020-02-19, 13:07:47 (67.189.165.218)
OK... so I trust the 12hy number is accurate. Unfortunately if you shrink the gap you will increase inductance at the cost of DC current capability so you need to be careful. this brings up the next .......
334: Tube DIY Asylum, RE: High input or output impedance (0.00)
Posted by dave slagle on 2020-02-19, 09:09:37 (67.189.165.218)
The bottom line, the reactive ohms involved requires an amount of current for a given voltage to be present. Just the same as if that load were resistive ohms. it actually can be worse for the react .......
335: Tube DIY Asylum, RE: ITC inductance question (0.00)
Posted by dave slagle on 2020-02-19, 08:52:32 (67.189.165.218)
Is the 300B operating as a cathode follower? How are you coming up with the 12HY number? dave .......
336: Vinyl Asylum, RE: There has been research on this.. (0.00)
Posted by dave slagle on 2020-02-17, 09:52:38 (174.192.145.125)
the ocular cavities are high frequency input ports to the brain. the article linked below explains it. one other thing i thought was odd prior to reading this is the suggestion to wear safety glasses .......
337: Tube DIY Asylum, RE: "bifilar windings in series will most certainly affect HF..." (0.00)
Posted by dave slagle on 2020-02-12, 06:20:58 (67.189.165.218)
I looked back and it seems you used two discrete 126's in series which is quite different than placing the bifilar pair of wires in series. This still does not explain why you had compromised results .......
338: Tube DIY Asylum, RE: IT as plate choke (0.00)
Posted by dave slagle on 2020-02-10, 10:16:10 (67.189.165.218)
Your TVC presumably has two discrete identical primary windings each with 1/2 the turns of the entire tapped secondary. This means when you parallel them you effectively get a 1:2 step up ratio from .......
339: Tube DIY Asylum, RE: No - I tried both ways around, didn't work (0.00)
Posted by dave slagle on 2020-02-10, 10:00:35 (67.189.165.218)
I think you need to be more clear about your definition of "didn't work" Maybe some frequency response plots would clear this up. If I had to guess the 126 with the windings in parallel might be a b .......
340: Tube DIY Asylum, RE: No - I tried paralleling primary and secondary, didn't work. (0.00)
Posted by dave slagle on 2020-02-06, 05:52:42 (67.189.165.218)
the only way I can see the paralleling not working correctly is if you had one of the windings reversed. The thing that you should not do with the bifilar windings is to put them in series because the .......
341: Tube DIY Asylum, RE: IT as plate choke (0.00)
Posted by dave slagle on 2020-02-06, 05:48:28 (67.189.165.218)
inductance and current capability stays the same and the DCR gets cut in half. dave .......
342: Tube DIY Asylum, RE: IT as plate choke (0.00)
Posted by dave slagle on 2020-02-05, 09:37:19 (67.189.165.218)
in the case of the 126 which is bifilar the best thing is to simply parallel the primary and secondary. dave .......
343: Tubes Asylum, RE: Dirty Little Secrets. (0.00)
Posted by dave slagle on 2020-01-26, 10:25:11 (67.189.165.218)
I guess you would need to look at a sample of 100 tubes of different types to get a better feel for what is really going on. More importantly looking at the section to section behavior of each would a .......
344: Tube DIY Asylum, RE: so what am I doing wrong? (0.00)
Posted by dave slagle on 2020-01-26, 06:03:30 (67.189.165.218)
You are not drawing any current in your PSUD2 sim. Put a 100ma load at the output of your sim and your voltages should be close. dave .......
345: Tubes Asylum, RE: Dirty Little Secrets. (0.00)
Posted by dave slagle on 2020-01-26, 05:57:23 (67.189.165.218)
I'm not sure I would use the word useless. I think it is telling that he had a tube that had one section that flashed and another that didn't.... that tells me something isn't right. here is the flash .......
346: Vinyl Asylum, RE: Unless I missed something, that link does not indicate nude or bonded. nt (0.00)
Posted by dave slagle on 2020-01-23, 06:21:10 (67.189.165.218)
Typically nude means that the diamond is fit through a hole in the cantilever and adhered by glue to stay in place. The idea is that the "press fit" gives all of the required rigidity and the glue is .......
347: Tubes Asylum, RE: WE6CA7 Plus Shuguang in Marantz 8B (0.00)
Posted by dave slagle on 2020-01-11, 06:42:35 (67.189.165.218)
Yet another tube with a WE designation that Western Electric never made. dave .......
348: Vinyl Asylum, RE: Riverstone Audio Record-Level Stylus Tracking Force Gauge. (0.00)
Posted by dave slagle on 2020-01-02, 06:43:59 (67.189.165.218)
Interesting 1/2g seems like a lot.... I just measured a JVC UA-7045 with and without AS and the VTF didn't change. I didn't bother on the Schröder since the AS is set by the twist of the string and no .......
349: Tube DIY Asylum, RE: Exchanging tubes (0.00)
Posted by dave slagle on 2020-01-01, 16:14:57 (67.189.165.218)
He may mean tubes like the KR VV302 or AVVT 302 which are beefed up 300B's and should be drop in replacements if the higher filament current is accounted for. dave .......
350: Tube DIY Asylum, RE: If a grid stop is bring driven by a 600 ohm source (0.00)
Posted by dave slagle on 2019-12-30, 18:48:55 (67.189.165.218)
you said it was the low pass filter made by the stopper and the miller capacitance that solves the issue of oscillation. take 150Ω against 100p and you get a f3 of 10Mhz... get crazy and take th .......
351: Tube DIY Asylum, RE: No worries with grid stoppers. (0.00)
Posted by dave slagle on 2019-12-28, 09:28:52 (67.189.165.218)
what you are doing with the grid stop is simply using the Miller Effect to cause a roll off What??? The typical grid stop is if the order of 100Ω which when added in series with the driving impedanc .......
352: Tube DIY Asylum, RE: Fundamental Concepts (0.00)
Posted by dave slagle on 2019-12-21, 06:42:13 (67.189.166.184)
.Ferrite beads don't work properly in this application due to their inductance. A few years back I proposed that if ferrite beads were an accepted means to quell oscillations, it seemed odd to searc .......
353: High Efficiency Speaker Asylum, RE: I think the important thing to remember is sensitivity (SPL) varies with distance -- (0.00)
Posted by dave slagle on 2019-12-13, 06:34:06 (67.189.166.184)
I guess this comes down to the definition one uses of a line array. Is it a visual definition which simply means a number of similar drivers in a line or is there a technical definition where a certai .......
354: Tubes Asylum, RE: Considering purchase of PSVANE CV181-TII Tubes from these folks (0.00)
Posted by dave slagle on 2019-12-12, 09:43:17 (67.189.166.184)
The reference I saw said it had the exact same construction and electrical characteristics of the Western Electric WE6SN7. This would be rather difficult since Western Electric never made that tube. .......
355: Tubes Asylum, RE: Considering purchase of PSVANE CV181-TII Tubes from these folks (0.00)
Posted by dave slagle on 2019-12-12, 07:11:57 (67.189.166.184)
Am I the only one that finds it to be outright fraud to suggest that Western Electric ever made a 6SN7? dave .......
356: High Efficiency Speaker Asylum, RE: I think the important thing to remember is sensitivity (SPL) varies with distance -- (0.00)
Posted by dave slagle on 2019-12-12, 05:35:37 (67.189.166.184)
I thought that once line array behavior is established, increasing the length does not increase efficiency. For a given frequency (wavelength) as the line array is shortened, the behavior will slowly .......
357: Tube DIY Asylum, RE: I'm confused gentlemen.... (0.00)
Posted by dave slagle on 2019-12-08, 19:15:33 (67.189.166.184)
they use gas filled thyratrons in radar, but for the life of me iI can't think of any audio use for these tubes I can..... dave .......
358: SET Asylum, RE: Webster output transformers (0.00)
Posted by dave slagle on 2019-12-03, 09:54:10 (67.189.166.184)
Generally PP outputs do not perform very well SE because the ground reference that all of the capacitances are designed around is moved from the CT to another location. This can make the high frequenc .......
359: SET Asylum, RE: Webster output transformers (0.00)
Posted by dave slagle on 2019-12-02, 06:56:15 (67.189.166.184)
the whole small gap thing is actually hugely misunderstood when it comes to EI lams. The only way to get a gap "suitable" for any DC offset is to have a completely discrete gap with all of the E's on .......
360: SET Asylum, RE: Webster output transformers (0.00)
Posted by dave slagle on 2019-11-29, 05:31:11 (67.189.166.184)
chances are there will always be some DC offset. Adding a small gap helps account for this and allows a much wider range of "acceptable" operation at the cost of a bit of inductance. dave .......
361: Vinyl Asylum, RE: I ported these tools from the original Cartridge Database... (0.00)
Posted by dave slagle on 2019-11-22, 10:33:05 (67.189.166.184)
hey, I presume the 220Ω-1KΩ are the loads that the cartridge sees and that is inline with what I would expect going straight into a head amp or loading the primary of a well behaved SUT. In order to g .......
362: Vinyl Asylum, RE: I ported these tools from the original Cartridge Database... (0.00)
Posted by dave slagle on 2019-11-21, 04:28:16 (67.189.166.184)
using the transformer to reflect back a desired load is a fool's errand since the transformer will show more effect from the load than the cartridge. The proper way to approach this is to find the sec .......
363: Vinyl Asylum, RE: 47k job done (0.00)
Posted by dave slagle on 2019-11-20, 17:26:45 (67.189.166.184)
I agree 100% with you that the loading does not have a profound effect on the HF response of the cartridge. It does however resemble the results of varying seconddary loads on a ringing transformer. I .......
364: Vinyl Asylum, RE: 47k job done (0.00)
Posted by dave slagle on 2019-11-20, 06:11:02 (67.189.166.184)
John, it is interesting that you post a link that has this image connected to it. I have seen it before and do not know the exact origin but it doesn't look like an honest test of loading for any .......
365: Tube DIY Asylum, RE: Have you heard it? (0.00)
Posted by dave slagle on 2019-11-19, 05:08:34 (67.189.166.184)
I have not heard the version NAZ built for obvious reasons but have another frustomer in NYC built a variation and is quite happy with it. I have yet to get to hear it but he does have 5 globe 50's fo .......
366: Vinyl Asylum, RE: Question/Recommendation on MC Step-Up Transformer (0.00)
Posted by dave slagle on 2019-11-18, 12:52:18 (67.189.166.184)
that should get you to -1dB @21Khz. dave .......
367: Vinyl Asylum, RE: Question/Recommendation on MC Step-Up Transformer (0.00)
Posted by dave slagle on 2019-11-18, 05:57:43 (67.189.166.184)
Hey, For this situation you really want something in the 1:7 step up ratio. The SS MI carts list 2.75mhy of coil inductance and that works against the reflected load to determine the high frequency ex .......
368: Tube DIY Asylum, RE: I saw a LCR type circuit and it had... (0.00)
Posted by dave slagle on 2019-11-18, 05:26:32 (67.189.166.184)
he goes through his build at the link below so I think it is fair to say it is in the public domain. .......
369: High Efficiency Speaker Asylum, RE: Hmmm Intrigued I looked at these nutters... (0.00)
Posted by dave slagle on 2019-09-15, 06:51:07 (67.189.166.184)
rather than snipe, why not open a line of discussion with these "nutters" on a public forum :-) dave .......
370: High Efficiency Speaker Asylum, RE: cult of the arcane ;) (0.00)
Posted by dave slagle on 2019-09-14, 07:36:04 (67.189.166.184)
We listened to a bunch of different combos on Walters dual 1428's and they all made a difference. The selenium rectified CLC filters he was using were bettered by the tungar LCLC supplies and interest .......
371: Tube DIY Asylum, RE: Class A (0.00)
Posted by dave slagle on 2019-09-06, 06:53:24 (67.189.166.184)
FWIW, I have seen that type of crazy behavior come and go in LT spice with diode selection. I have actually had certain diodes "hang up" spice or make a sim take exceedingly long to run. When this hap .......
372: Tube DIY Asylum, RE: Dimensions? (0.00)
Posted by dave slagle on 2019-08-23, 19:35:52 (67.189.166.184)
The ones I have are 4" X 1.75" I'm guessing the extra filament windings add a little to the "standard" 50VA winding. John is updating his site but the listing for the AS-05TC150 is not 100% correct. B .......
373: Tube DIY Asylum, New Antek 50VA power Transformers. (0.00)
Posted by dave slagle on 2019-08-20, 11:47:29 (67.189.166.184)
I talked John at Antek into making some 50VA transformers for a phono stage and he did a whole series. These have dual secondary windings for FWCT connection and two 6.3V windings with one of them tap .......
374: Vinyl Asylum, RE: Denon 103D photo (0.00)
Posted by dave slagle on 2019-08-06, 17:21:23 (67.189.166.184)
The 1º cantilever angle tolerance is overshadowed by the ±5º tolerance on the Zenith typical of the designs I have seen. dave .......
375: Tube DIY Asylum, RE: Choke Loading (0.00)
Posted by dave slagle on 2019-07-24, 09:43:15 (67.189.166.184)
About 15-20 years ago there was a trend of placing the output transformer in the cathode for just the reasons you state. Since output tubes are typically low mu, the argument was that the slight loss .......
376: Tube DIY Asylum, RE: Adjustable B+ : Powerstat 10C (0.00)
Posted by dave slagle on 2019-07-11, 08:31:53 (67.189.166.184)
built it 20 years ago for JC's NY Noize get together. It was a WE437A It coupled to a Mesh 50 with permalloy outputs by Micheal Ulbrich. It was even written up in stereophile. .......
377: Tube DIY Asylum, RE: Adjustable B+ : Powerstat 10C (0.00)
Posted by dave slagle on 2019-07-11, 05:58:47 (67.189.166.184)
nah... I think he should take it in the other direction and add wheels. .......
378: Vinyl Asylum, test record with 15khz tone. (0.00)
Posted by dave slagle on 2019-07-10, 14:13:30 (67.189.166.184)
I am looking for a test record with an easy to cue fixed 15khz tone that preferably lasts fo 30 seconds or more. I want to be able to measure the distortion using a fft and compare that to a microscop .......
379: Tube DIY Asylum, RE: on followers (0.00)
Posted by dave slagle on 2019-07-08, 10:58:52 (67.189.166.184)
nice... it is interesting to see crowhurst states that loading destroys the low distortion advantages and then to see the editor chime in with a 1:100 source to load ratio as a minimum. dave :: .......
380: Tube DIY Asylum, RE: Thanks for responding... (0.00)
Posted by dave slagle on 2019-07-08, 07:35:33 (67.189.166.184)
By difficult load I mean anything other than a CCS. :-) a low impedance load is an issue since that defeats any added benefits of the CCS. a varying impedance load will alter the sound dynamically as .......
381: Vinyl Asylum, RE: Hmmmm (0.00)
Posted by dave slagle on 2019-07-08, 06:07:10 (67.189.166.184)
Thanks for that. by extension of the "spacing" logic why don't we use a 20MHz to get to the bottom of the groove :-) dave .......
382: Tube DIY Asylum, RE: Thanks for responding... (0.00)
Posted by dave slagle on 2019-07-08, 05:55:57 (67.189.166.184)
The 800 pound Schrödinger's cat in the corner here is: If a cathode follower needs a near infinite load to sound its best then how can it be expected to take advantage of its low output impedance to d .......
383: Tube DIY Asylum, RE: I got to thinking..... that was my first mistake (0.00)
Posted by dave slagle on 2019-07-07, 15:49:03 (67.189.166.184)
Hey, The problem with AW's approach to cathode followers is by the point they get to sounding "transparent" (infinite value load) the low output impedance serves no useful purpose. dave .......
384: Vinyl Asylum, RE: Methinks you worry too much about these things... (0.00)
Posted by dave slagle on 2019-07-01, 11:18:23 (67.189.166.184)
There is the side effect where you also avoid rising distortion from mastering too close to the inner grooves but that was not my point. This is the only real explanation that I can see as to why th .......
385: Vinyl Asylum, RE: No...nt (0.00)
Posted by dave slagle on 2019-06-30, 14:05:29 (67.189.166.184)
No to what? are you suggesting that assuming no compression is used cutting hotter results in more distortion? lets assume that a single 4 minute cut is all that is needed to fit on the side. At some .......
386: Vinyl Asylum, RE: They don't have to... (0.00)
Posted by dave slagle on 2019-06-29, 04:21:13 (67.189.166.184)
Aren't you confusing noise, headroom and compression. I agree that if you move to cut hotter eventually you will run out of space and then will need compression to compensate. However if there is dead .......
387: Tube DIY Asylum, RE: I do not want to hear the room I want to hear what the musicians did, together, in the space they were in. (0.00)
Posted by dave slagle on 2019-06-23, 09:16:50 (67.189.166.184)
since you exist in the room... how can you "unhear it" I have not had good experiences with pre-distorting signals to correct for anything. The biggest issue I have with DPS EQ (aside from it being di .......
388: Tube DIY Asylum, RE: Room & spkr DSP Eq along with careful positioning can pretty well nail that. (0.00)
Posted by dave slagle on 2019-06-22, 15:05:22 (67.189.166.184)
the only problem with that approach is if you record a solo violin in a room and then play it back through an EQ'd flat system in that room you will have two very different sounds. The live violin wil .......
389: Tube DIY Asylum, RE: I have a problem with the following statement in the introduction. (0.00)
Posted by dave slagle on 2019-06-22, 07:51:18 (67.189.166.184)
I do not believe that the level of high order harmonic distortion components is as important as such a reasonably flat frequency response at the listening seat. it depends on your definition of "rea .......
390: Tubes Asylum, RE: Remember, the heater voltage is 6.3VAC (0.00)
Posted by dave slagle on 2019-06-13, 06:07:00 (67.189.166.184)
Wired in parallel (within the tube), the 12AX7 heaters = 12.6VAC. Wired in series (within the tube), the 6SN7 = 6.3 volts. did you mean: Wired in Series (within the tube), the 12AX7 heaters = 12.6VA .......
391: Tube DIY Asylum, RE: I disagree, it's not just his manner, his circuit ideas don't stack up, either. (0.00)
Posted by dave slagle on 2019-06-12, 05:49:34 (67.189.166.184)
I designed a preamp for a friend a number of years ago that used a 12B4 loaded with a TVC that had an offset winding that would null the primary current for a net total of no DC magnetization of the c .......
392: Tube DIY Asylum, RE: I disagree, it's not just his manner, his circuit ideas don't stack up, either. (0.00)
Posted by dave slagle on 2019-06-11, 10:50:09 (67.189.166.184)
there was no shortage of people here who also insisted they couldn't sound good. I have never heard one but given the number of positive reports makes it question who to trust. On one hand you have pe .......
393: Tube DIY Asylum, RE: I disagree, it's not just his manner, his circuit ideas don't stack up, either. (0.00)
Posted by dave slagle on 2019-06-11, 05:59:50 (67.189.166.184)
John Hogan is a perfect example of this. His amps took a lot of abuse from the slide rule club because the ungapped PP outputs would surely saturate with the DC current required for SE operation. If .......
394: Vinyl Asylum, RE: " You simply need to exchange the 47K input resistor for a higher value" ... (0.00)
Posted by dave slagle on 2019-06-10, 06:44:29 (67.189.166.184)
I guess you missed the intention of my ;-) poking fun at the marketing speak that would be used for such a silly idea as a buffered SUT. I have built a number of active stages with the hopes of comin .......
395: Vinyl Asylum, RE: " You simply need to exchange the 47K input resistor for a higher value" ... (0.00)
Posted by dave slagle on 2019-06-09, 05:06:48 (67.189.166.184)
I think that is a flaw / misunderstanding from the manufacturers perspective. The 47K resistor is for the most part a remnant from the past. Many phono's offer adjustable loading making the values suc .......
396: Vinyl Asylum, RE: Phono pre vs step-up transformer (0.00)
Posted by dave slagle on 2019-06-08, 06:12:47 (67.189.166.184)
But if your cart really prefers a higher loading ... you aren't able to get it. Of course you can. You simply need to exchange the 47K input resistor for a higher value. That resistor value is there .......
397: Vinyl Asylum, RE: Just to mess with your head.... (0.00)
Posted by dave slagle on 2019-06-06, 19:05:21 (67.189.166.184)
that looks like a really steep cantilever angle. Can you take a better profile shot? dave .......
398: Vinyl Asylum, RE: OK... (0.00)
Posted by dave slagle on 2019-06-04, 06:02:52 (67.189.166.184)
But 0.7 gm is a rather large VTF range in most setups. Most of us set our VTF within 0.2 gm of the recommended VTF and there it stays. I'm not sure if it is a purely linear progression but when that .......
399: Vinyl Asylum, RE: How much the VTF efffects the SRA... (0.00)
Posted by dave slagle on 2019-06-03, 11:47:32 (67.189.166.184)
I measured sra change vs. VTF with a denon 103 once which errs on the stiff side of the suspension spectrum. Over the range of 1.8 to 2.5g I measured a 1.3º difference in cantilever angle. If you do t .......
400: Vinyl Asylum, RE: Nagatron Z coupler mc transformer info? (0.00)
Posted by dave slagle on 2019-05-31, 05:39:17 (67.189.166.184)
The Nagotron HV-9100 was a low impedance ribbon cartridge so this is probably the mating SUT for it. dave .......
401: Tube DIY Asylum, RE: chokes ... on sale now (0.00)
Posted by dave slagle on 2019-05-29, 05:44:05 (67.189.166.184)
that 25Vac number seems low. It is unfortunate that they don't associate a frequency with that number. All of the turns needed to get the 225hy @ 15ma pretty much assures that the AC flux is going to .......
402: Tube DIY Asylum, RE: what is the watts rating of 3k xformer in your sim? -nt (0.00)
Posted by dave slagle on 2019-05-23, 08:46:48 (67.189.166.184)
the wattage of the transformer doesn't really come into play for the sake of this discussion and the related simulations. It can be assumed that transformer saturation is a separate issue that will c .......
403: Tube DIY Asylum, RE: True for small signals, not for max power (0.00)
Posted by dave slagle on 2019-05-22, 12:34:18 (67.189.166.184)
it is the idea that you cannot increase the inductance without paying the price on the top end that is central to the choice of compromise. Early on I found that I much preferred the sound of the J .......
404: Tube DIY Asylum, RE: A reference! (0.00)
Posted by dave slagle on 2019-05-22, 12:00:38 (67.189.166.184)
i saw that and if anything it supports my point that with triodes it is the characteristics of the circuit / tubes that dominates low frequency distortion and not the relationship of reflected load .......
405: Tube DIY Asylum, RE: True for small signals, not for max power (0.00)
Posted by dave slagle on 2019-05-22, 07:50:16 (67.189.166.184)
agreed on all points. Taken to the extreme now consider how a plate choke could possibly load a triode without infinite inductance. Whenever I bring this up I get met with the "the plate choke represe .......
406: Tube DIY Asylum, RE: True for small signals, not for max power (0.00)
Posted by dave slagle on 2019-05-22, 05:09:56 (67.189.166.184)
I find it interesting on how tight the pattern of 5 cycles gets as the inductance foes up. dave .......
407: Tube DIY Asylum, RE: True for small signals, not for max power (0.00)
Posted by dave slagle on 2019-05-21, 18:09:55 (67.189.166.184)
sure.... it is unclear to me why the LF samples originate at the static operating point and shift to be centered around it and these seem tied to it. tried 60 120 and 240hz on the same graph and it .......
408: Tube DIY Asylum, RE: True for small signals, not for max power (0.00)
Posted by dave slagle on 2019-05-21, 15:13:20 (67.189.166.184)
I do find it interesting that you empirical method seems to pretty closely correspond with the 0ma current cutoff that the sims show. I also find it interesting that in the case where the frequency we .......
409: Tube DIY Asylum, RE: Have you seen the article by voltsec..... (0.00)
Posted by dave slagle on 2019-05-21, 14:21:59 (67.189.166.184)
FWIW I am actually the cause of that article :-) it all stemmed around the use of an 845 and a tap swapped OT with 27hy's to reflect 16K for use in a "low power 845" amp. Today I still say is not the .......
410: Tube DIY Asylum, RE: Electraprint DRD 300B (0.00)
Posted by dave slagle on 2019-05-21, 09:24:01 (67.189.166.184)
So the 5k transformer, when loading a low Rp tube, does not really need more inductance than a 3k load. that is and has been my contention for years now. I suspect that we can become conditioned to .......
411: Tube DIY Asylum, RE: yes and no (0.00)
Posted by dave slagle on 2019-05-21, 08:54:46 (67.189.166.184)
lets put some pictures to the situations you posed above. I am using Stephie Bench's spice file to plot loadlines to see if we can better reconcile this concept. There are 10 loops for each line and i .......
412: Tube DIY Asylum, RE: True for small signals, not for max power (0.00)
Posted by dave slagle on 2019-05-21, 07:47:21 (67.189.166.184)
do you have a pointer to a treatment of the power bandwidth being related to the load impedance? For years I have seen people go on about the small signal vs. large signal treatment and how different .......
413: Tube DIY Asylum, RE: Electraprint DRD 300B (0.00)
Posted by dave slagle on 2019-05-20, 14:05:46 (174.220.23.41)
If this were a pentode amp where the inductance works against the reflected load I would agree. Since this is a triode amp the support for bass is for the most part dominated by relationship between t .......
414: Vinyl Asylum, RE: Denon DL-103 re-tipped sounding very disappointing (0.00)
Posted by dave slagle on 2019-05-13, 08:07:22 (67.189.166.184)
keeping the armwand parallel to the record surface as a start is fine for new cartridges where there is a reasonable expectation that the cart was designed to operate in this manner. In the case of a .......
415: Vinyl Asylum, RE: Denon DL-103 re-tipped sounding very disappointing (0.00)
Posted by dave slagle on 2019-05-13, 05:24:31 (67.189.166.184)
try taking your SRA up substantially. dave .......
416: Tube DIY Asylum, RE: Why would that 470uF capacitor be called "Ultrapath"? (0.00)
Posted by dave slagle on 2019-04-30, 11:17:20 (67.189.166.184)
The B= is also at AC ground through the last PS cap. The thinking behind the ultra-path is that connecting the cap to the B+ and having an unbypassed cathode resistor allows for a single cap to comple .......
417: Vinyl Asylum, RE: Impedence/Load of an SUT (0.00)
Posted by dave slagle on 2019-04-30, 10:25:22 (67.189.166.184)
everybody tends to phrase things in a different way. the reflected load of the ortophon is indeed 183 ohms assuming that silly 47K is there but this number should have nothing to do with the impedance .......
418: Vinyl Asylum, RE: Impedence/Load of an SUT (0.00)
Posted by dave slagle on 2019-04-30, 05:02:53 (67.189.166.184)
How do they manage to match a SUT to a cartridge with an internal impedance of only 2 ohms with a 1:16 ratio when it actually presents a load of around 175 ohms ? in a sane world people would under .......
419: Tube DIY Asylum, RE: Sorry here is the circuit (0.00)
Posted by dave slagle on 2019-04-30, 04:20:00 (67.189.166.184)
I don't see the point of the UP cap in this circuit since the low impedance of the diodes puts the cathode at AC ground which for the most part eliminates the need for a bypass cap. It can be argued t .......
420: Tube DIY Asylum, RE: Are you looking to get a certain sound or are you trying A2? (0.00)
Posted by dave slagle on 2019-04-28, 19:38:52 (67.189.166.184)
mu is around 25 and Rp is in the 13K range for those operating points. we used in in the 50 amp we took to ETF last fall.... funny thing is I think there is a really good chance that the 50 picture .......
421: Vinyl Asylum, RE: 103 hum (0.00)
Posted by dave slagle on 2019-03-31, 16:34:28 (67.189.166.184)
My guess is the 40 ohm impedance of the denon is turning your cabling into an antenna. all of the other "hum free" carts have a fraction of the impedance of the 103. dave .......
422: High Efficiency Speaker Asylum, RE: Yes, I laugh what with all the obsession of out to 20K, 95% drop like a rock after 12K~nT (0.00)
Posted by dave slagle on 2019-03-01, 06:16:47 (67.189.166.184)
If you assume that the ears are the only means of sensing high frequency information then I concur. Dick Sequerra once told me that the ocular cavities are major receptors to ultrasonic information an .......
423: SET Asylum, RE: But there are other serious drawbacks to consider with Direct Coupling (0.00)
Posted by dave slagle on 2019-02-25, 12:19:07 (67.189.166.184)
The elektromekano M-7 µ~110 rP= 85K S=1.3 dave .......
424: SET Asylum, RE: 2A3 Direct Coupled VS. Capacitor coupled (0.00)
Posted by dave slagle on 2019-02-23, 07:25:48 (67.189.166.184)
Minor tidbit... When you say to avoid blocking distortion a grid needs low impedance to ground, you really should say it needs a low DC resistance to ground. Impedance is an AC characteristic and the .......
425: Vinyl Asylum, RE: An interesting find from a coworker (0.00)
Posted by dave slagle on 2019-01-30, 07:14:26 (67.189.166.184)
raise the VTA by about 1.5" remove the aluminum shipping cover and enjoy! also remember to never de-spool it since getting it rewound to the right tension to keep the integrity of the recorded mat .......
426: Tube DIY Asylum, RE: Dynaco ST-70 in Triode Mode (0.00)
Posted by dave slagle on 2019-01-27, 06:45:08 (67.189.166.184)
and triode wire the pentode section of the 7199 and ditch the feedback :-) The thing that surprised me most about triode wiring one is how at ~1/2 the power it seemed to play louder. granted 1/2 the .......
427: Tube DIY Asylum, RE: RCA Phono Preamp (0.00)
Posted by dave slagle on 2019-01-21, 07:14:39 (67.189.166.184)
what inverse riaa are you using? If you use an iriaa like the hagerman with the third (neumann) time constant added and a stage that doesn't include that filter like the RCA will be 0.9dB down at 20Kh .......
428: Tube DIY Asylum, RE: The single-ended nature of air !!! (0.00)
Posted by dave slagle on 2019-01-08, 09:01:31 (67.189.166.184)
cool.... thanks for the follow up. dave .......
429: Tube DIY Asylum, RE: Interesting (0.00)
Posted by dave slagle on 2019-01-05, 07:59:21 (67.189.166.184)
In effect I think you get a kind of variable signal level dependent null and in case I wasn't clear I prefer a sound with 2nd order dominating and declining amounts of the rest even if it comes at the .......
430: Tube DIY Asylum, RE: Harmonic Cancellation (0.00)
Posted by dave slagle on 2019-01-04, 21:04:36 (67.189.166.184)
It does work and the tell tale signature can be seen in the FFT where the odds dominate. At low levels the traditional even domination of SE holds and at some point it transitions to the odd dominatin .......
431: Tube DIY Asylum, RE: The single-ended nature of air !!! (0.00)
Posted by dave slagle on 2019-01-04, 20:39:24 (67.189.166.184)
I am assuming that this is a balanced output with a symmetrically wound transformer to minimize any effect of moving the ground reference on a SE transformer.. :-) dave .......
432: Tube DIY Asylum, RE: Harmonic Cancellation (0.00)
Posted by dave slagle on 2019-01-04, 20:33:31 (67.189.166.184)
correct on the phase thing wrt even harmonics. You are also correct on the concept that for a given tube used as both driver and output the driver will not distort anywhere near enough to appreciably .......
433: Tube DIY Asylum, RE: Q & A (0.00)
Posted by dave slagle on 2019-01-04, 06:43:19 (67.189.166.184)
What is it about the phono section that is so susceptible to loading and conversely how does the balance control load it down? Typically the volume / balance and tone controls would driven with a cath .......
434: Vinyl Asylum, RE: Magnet types in carts ?. (0.00)
Posted by dave slagle on 2019-01-03, 11:37:34 (67.189.166.184)
From what I gather SmCo was pushed aside by neo in the quest for higher flux. I have heard a number of SmCo based carts that I like but have yet to hear a Neo based one that doesn't drive me from the .......
435: Tube DIY Asylum, RE: Block Diagram (0.00)
Posted by dave slagle on 2019-01-03, 11:12:06 (67.189.166.184)
do you have the diagram for the tone circuit and what is it's output impedance? I presume the 180K series resistor is to set a "stabilized" source impedance much like is typically done for phono. The .......
436: Tube DIY Asylum, RE: Miller Effect (0.00)
Posted by dave slagle on 2019-01-03, 08:52:00 (67.189.166.184)
assuming the pot is a multiple of the drive impedance as to not load it down, a 250K will have a max output Z of around 65K worst case (-6dB). TK mentions that there are other tone controls and a bala .......
437: Vinyl Asylum, RE: Cartridge, Stylus longevity (0.00)
Posted by dave slagle on 2019-01-03, 07:04:22 (67.189.166.184)
so my memory isn't that far off... do you have a pointer to the source of your info? It very well may be that I was simply remembering you making this statement rather than reading it elsewhere. What .......
438: Vinyl Asylum, RE: Magnet types in carts ?. (0.00)
Posted by dave slagle on 2019-01-03, 06:56:41 (67.189.166.184)
I believe the predecessor to neo in the rare earth camp was samarium cobalt. dave .......
439: Vinyl Asylum, RE: Cartridge, Stylus longevity (0.00)
Posted by dave slagle on 2019-01-01, 07:44:27 (67.189.166.184)
As another point of reference the Jico SAS is rated at 500 hours which they claim is 2-3 times that of other styli. All info points to the SAS using a namiki Micro-Ridge which i believe to be the bes .......
440: Tube DIY Asylum, RE: 100V P-P (0.00)
Posted by dave slagle on 2019-01-01, 07:30:24 (67.189.166.184)
in your first post you say the gain is 16 or 25 and then above you say the intended gain is 6dB.... what accounts for the discrepancy? I agree with chip that if you have that much gain and swing, much .......
441: Tube DIY Asylum, RE: Grasping at Theoretical Straws (0.00)
Posted by dave slagle on 2018-12-30, 15:04:38 (67.189.166.184)
Well... I think you need to take into consideration what kind of speaker you are talking about. I tend to agree that a driver in an open baffle where the room volume is an unimpeded load on the driver .......
442: Tube DIY Asylum, RE: Grasping at Theoretical Straws (0.00)
Posted by dave slagle on 2018-12-30, 09:46:19 (67.189.166.184)
how can you separate the two? the speaker works in an environment filled with air. I guess this comes down to the caused of driver distortion and if air were linear, would the driver distortion chan .......
443: Tube DIY Asylum, RE: Grasping at Theoretical Straws (0.00)
Posted by dave slagle on 2018-12-30, 07:14:38 (67.189.166.184)
air rushes in to fill the vacuum left by the retreating diaphragm at a speed of 1,100 ft./second. this isn't a question of the speed that air moves but how much force it takes to compress and rarefy .......
444: Tube DIY Asylum, RE: The single-ended nature of air !!! (0.00)
Posted by dave slagle on 2018-12-30, 06:48:51 (67.189.166.184)
I agree. I guess I wasn't clear that the phase reversal in the digital domain and the phase reversal at the speaker with a PP amp was not anywhere near as audible and the phase reversal of a low power .......
445: Tube DIY Asylum, RE: The single-ended nature of air !!! (0.00)
Posted by dave slagle on 2018-12-29, 20:15:56 (67.189.166.184)
Think of the air load on the driver and not the sound traveling through air. This whole concept was pointed out to me by Johannes Chiu some 20 years ago and he demonstrated it on my lowthers in bigfu .......
446: Tube DIY Asylum, RE: Dual primary power trans as isolation transformer (0.00)
Posted by dave slagle on 2018-11-26, 16:38:05 (67.189.166.184)
Wow... When it comes down to the bifilar used for isolation the voltage gradient between wires is the same which is far less stressful than a pair of series wired bifilar 115's. dave .......
447: Tube DIY Asylum, RE: Dual primary power trans as isolation transformer (0.00)
Posted by dave slagle on 2018-11-25, 16:43:16 (67.189.166.184)
It seems unlikely that a dual primary transformer would have bifilar windings since if wired for 230V operation you would still have full line potential between the windings. dave .......
448: Tube DIY Asylum, RE: The Arrow (0.00)
Posted by dave slagle on 2018-10-22, 18:49:10 (67.189.166.184)
oops... I was confusing your mention of polarity and "upsinde down" with the physical orientation arrow. My bad. dave .......
449: Tube DIY Asylum, RE: Mercury Relays (0.00)
Posted by dave slagle on 2018-10-22, 05:14:15 (67.189.166.184)
that is a darn good question.... one which I haven't found a good answer to. While there are some position insensitive mercury whetted relays I had a bunch of alleged mercury relays without the arrow .......
450: Tube DIY Asylum, RE: What is this output trans tap for? (0.00)
Posted by dave slagle on 2018-10-15, 19:00:45 (67.189.166.184)
if there are only three taps as the OP said then cathode feedback is out. I think Tre' got it right with is being a UL tap. dave .......
451: Tube DIY Asylum, RE: Agreed, 10m probe doesnt make a difference (0.00)
Posted by dave slagle on 2018-09-20, 04:38:16 (67.189.166.184)
did you have the probes set on 10X? my (cheap) 10X probes measure 11pf on the 10X setting and 113pf on the 1X setting, so even on the 1X setting with an 8K source you should be flat to 20Khz. Do you h .......
452: Tube DIY Asylum, RE: Cable Plots-need lower Z preamp output (0.00)
Posted by dave slagle on 2018-09-19, 09:34:35 (67.189.166.184)
Yeah... I missed the day in audiophile university where they taught us that cables can have 1nf of capacitance. I just measured three pair here and both 1m pair were in the 90-100pf range and the 2m p .......
453: Tube DIY Asylum, RE: Cable Plots-need lower Z preamp output (0.00)
Posted by dave slagle on 2018-09-19, 05:02:00 (67.189.166.184)
Those results are crazy. I have seen RCA's take a hit to SUT's on the test bench but I was looking at 100Khz and the results were nothing even close to what you are getting. I guess the moral of the s .......
454: Tube DIY Asylum, RE: Dave, youre a genius! Now what? (0.00)
Posted by dave slagle on 2018-09-18, 04:54:17 (67.189.166.184)
Not a genius... just walked this path before. Try an RCA to BNC adapter and a 10X scope probe. scary thing is this is with a tube not much different from a 6SN7 Rp wise... now consider what you woudl .......
455: Tube DIY Asylum, RE: RE084 Frequency response rolloff (0.00)
Posted by dave slagle on 2018-09-17, 04:37:47 (67.189.166.184)
Do an input vs. output sweep of your test setup with 8K series resistor. Near as I can tell the RE084 should have an Rp of around 8K which isn't that high but I have seen the capacitance of a 1X scope .......
456: Tube DIY Asylum, RE: What Is it? (0.00)
Posted by dave slagle on 2018-09-11, 07:27:36 (67.189.166.184)
old skool dht guitar amp? dave .......
457: Vinyl Asylum, RE: Mods to DL-103r? (0.00)
Posted by dave slagle on 2018-09-02, 16:34:34 (67.189.166.184)
Hey, I essentially started with the denon 103 as a source for parts and I am slowly replacing every part to see what each thing adds to the "big picture". As mentioned below the stylus an cantilever i .......
458: Vinyl Asylum, RE: New TT (0.00)
Posted by dave slagle on 2018-08-28, 17:05:52 (67.189.166.184)
any more info on the Schröder-esque tonearm? dave .......
459: Tube DIY Asylum, RE: OPT recommendation for circlotron (0.00)
Posted by dave slagle on 2018-08-13, 05:35:39 (67.189.160.134)
I am not familiar with the exact topology you propose bit.... The first issue with using an autoformer in this situation is the lack of isolation would allow the speaker to rest at B+. This is just a .......
460: Tube DIY Asylum, RE: OPT recommendation for circlotron (0.00)
Posted by dave slagle on 2018-08-12, 07:16:57 (67.189.160.134)
Hey, there is a long thread on DIYaudio about toroids as outputs for some late night reading. I just measured an Antek- 0509 which is a 50VA 9V and with a 600R balanced source I was -1dB @ 31Khz into .......
461: Tube DIY Asylum, RE: OPT recommendation for circlotron (0.00)
Posted by dave slagle on 2018-08-12, 05:33:17 (67.189.160.134)
Hey, This might be a case where a power toroid will work quite well. I would look at a 30VA unit with 15V secondaries to begin with and it will let you get the circuit built with an inexpensive part. .......
462: Vinyl Asylum, RE: Variance between same cartridge models (0.00)
Posted by dave slagle on 2018-08-10, 04:58:51 (67.189.160.134)
do you have any pointers to documentation of mitch cotter working on this? Have you tried loading the cartridge directly with a 10 ohm resistor in addition to the 22 ohm reflected load? The reason I a .......
463: Vinyl Asylum, RE: Variance between same cartridge models (0.00)
Posted by dave slagle on 2018-08-09, 13:01:29 (67.189.160.134)
Denon recommends 100 ohms as the minimum load for the 103R (40 ohms with a SUT) which I read as they suggest 100ohms or higher. Your 7 ohm load puts you into the territory of current drive which is an .......
464: Vinyl Asylum, RE: Variance between same cartridge models (0.00)
Posted by dave slagle on 2018-08-09, 10:22:49 (67.189.160.134)
Hey, a 7 ohm load on a 14 ohm cartridge will cut the cartridge output to 33% which is roughly a 10dB loss. This effectively turns the 103r into a cart with a 0.08mv output. dave .......
465: Tube DIY Asylum, RE: That was a non-answer (0.00)
Posted by dave slagle on 2018-08-02, 15:24:24 (67.189.160.134)
Years ago I suggested using a pair of available EC8010 in place of an unobtainum EC8020 and was met with the idea that the single 8020 was a better approach because "all of the parts were in the same .......
466: Tube DIY Asylum, RE: That was a non-answer (0.00)
Posted by dave slagle on 2018-08-01, 07:13:05 (67.189.160.134)
I think we may be getting into the territory that the next argument will be all wire sounds the same. I am not trying to make a judgement about the use of parallel tubes but I am saying that the theor .......
467: Tube DIY Asylum, RE: That was a non-answer (0.00)
Posted by dave slagle on 2018-07-30, 16:37:42 (50.50.136.46)
If tubes had similar dynamic characteristics to resistors I would agree. But I somehow feel that if you parallel a 50 and a 10, your new composite tube will not be the same as a tube with a µ of 6 and .......
468: Tube DIY Asylum, RE: That was a non-answer (0.00)
Posted by dave slagle on 2018-07-30, 07:55:33 (50.50.136.46)
I think you may be taking a bit too much of a hard line approach. So what happens if you ignore the bottles and connect a single plate 2A3 and a 45 in parallel? By your argument you would simply end u .......
469: Tube DIY Asylum, RE: That was a non-answer (0.00)
Posted by dave slagle on 2018-07-29, 08:53:52 (50.50.136.46)
Yes... and I consider the EC8010 as near the ideal for the parallel plate model.. I have often mused using a pair in parallel to achieve better results than a single EC8020 because the two sections co .......
470: Tube DIY Asylum, RE: That was a non-answer (0.00)
Posted by dave slagle on 2018-07-29, 07:54:12 (50.50.136.46)
playing devils advocate here one could visualize it and a single AGK structure of a tube like the EC8010 as a very large number of structures in parallel to give the average characteristics. Now add a .......
471: Tube DIY Asylum, RE: That was a non-answer (0.00)
Posted by dave slagle on 2018-07-28, 08:31:30 (50.50.136.46)
Well.... :-) I can actually make the argument that the single tube built as drawn as a symbol (which is how the EC8010 is built) can also be viewed as multiple tubes in parallel. For ease of illustrat .......
472: Vinyl Asylum, RE: Who here cleans records with WD-40? (0.00)
Posted by dave slagle on 2018-07-27, 12:24:18 (50.50.136.46)
sure does.... I didn't make it that far. thanks dave .......
473: Vinyl Asylum, RE: Who here cleans records with WD-40? (0.00)
Posted by dave slagle on 2018-07-27, 08:24:00 (50.50.136.46)
I looked for the part of the video where he applies the WD-40 to see which version he uses and couldn't find it. WD-40 does make a contact cleaner that can be used to remove the flux from circuit boar .......
474: Tube DIY Asylum, RE: 304tl (0.00)
Posted by dave slagle on 2018-07-16, 05:31:47 (67.189.160.134)
Dennis, I have asked Jeff this on several occasions when he has went on his parallel tubes "blur" the sound rants so I will also ask you. If you consider the biplate 2a3 as two tubes in parallel with .......
475: Tube DIY Asylum, RE: 304tl (0.00)
Posted by dave slagle on 2018-07-15, 18:18:34 (67.189.160.134)
That wasn't mine....it was Jeffrey Jacksons. .......
476: Tube DIY Asylum, RE: 304tl (0.00)
Posted by dave slagle on 2018-07-15, 04:31:18 (67.189.160.134)
The true audiophile would never accept the series connection since it biases 2 of the plate structures 5V away from the other two. The effect of this can easily be seen by how the plates cherry up. Wh .......
477: Vinyl Asylum, RE: Step up series wired coil calculator (0.00)
Posted by dave slagle on 2018-07-12, 06:21:34 (67.189.160.134)
I suspect John is correct below and it is two identical windings that can give 30 or 36dB of gain depending how they are wired. However if they are two discrete windings of 30 and 36dB then you have a .......
478: Tube DIY Asylum, RE: Okay, this isnt funny (0.00)
Posted by dave slagle on 2018-06-29, 05:54:20 (67.189.160.134)
You are missing two things.... The first is nowhere was it stated that you must adhere to the maximum Eb to apply this "technique" and a rational approach would be to start with your desired plate dis .......
479: Tube DIY Asylum, RE: Okay, this isnt funny (0.00)
Posted by dave slagle on 2018-06-29, 05:41:03 (67.189.160.134)
I think you are conflating anode current and bias voltage with the references to others on the forum and as you know they are very different things. The engineering suggestion you found loosely transl .......
480: Tube DIY Asylum, RE: Latest build: 6C6 direct-couple 2A3 (0.00)
Posted by dave slagle on 2018-06-25, 18:15:38 (67.189.160.134)
Hey, I really like the approach of building and listening to form opinions and then going to measurements to attempt to quantify what we hear. dave .......
481: Tube DIY Asylum, RE: Latest build: 6C6 direct-couple 2A3 (0.00)
Posted by dave slagle on 2018-06-25, 09:05:34 (67.189.160.134)
what is the value of the plate load resistor on the 6C6? is there any feedback? dave .......
482: Tube DIY Asylum, RE: Mouser (0.00)
Posted by dave slagle on 2018-06-05, 18:44:40 (67.189.160.134)
Not much of a line. The MRA series only has 13 values in stock. .......
483: Tube DIY Asylum, RE: The Takman Carbon Film resistors are very nice... (0.00)
Posted by dave slagle on 2018-06-05, 04:41:49 (67.189.160.134)
what is a good source for the mills resistors? .......
484: Tube DIY Asylum, RE: Japanese power transformers in the US? (0.00)
Posted by dave slagle on 2018-06-01, 04:33:51 (67.189.160.134)
Hey, The formula for AC flux is Flux= Ac voltage / (4*Core Area*Turns*frequency) substituting 1 as a value for core area and turns you se that AC flux is simply the relationship between voltage/frequ .......
485: Tube DIY Asylum, RE: input transformer (0.00)
Posted by dave slagle on 2018-05-30, 14:54:49 (67.189.160.134)
I do wonder if the original transformer is 100:600ct or 100:600+600. I would suspect it is 600CT since that is a typical value used. The spice sims I have run are what made me question your 4.7V n .......
486: Tube DIY Asylum, RE: input transformer (0.00)
Posted by dave slagle on 2018-05-30, 06:42:14 (67.189.160.134)
Power dissipated in the source and the load do not add flux to the core / cannot saturate a transformer. Does the dBm spec take into account the power dissipated in the source and the load and then c .......
487: Tube DIY Asylum, RE: input transformer (0.00)
Posted by dave slagle on 2018-05-29, 14:54:04 (67.189.160.134)
There is just a single 100 ohm primary so why are you multiplying the 100*2 ? I get 20dBm into 100 ohms to be 3.16V... the 1/2dB spec @ 15Khz bothers me more. I would be sure to run a frequency sweep .......
488: Tube DIY Asylum, RE: LCR meters (0.00)
Posted by dave slagle on 2018-05-27, 19:11:27 (67.189.160.134)
to further put a point on what PJ said... most audio chokes have a self resonance in the neighborhood of 1kHz so any meter that samples at the frequency generally gives incorrect readings. Meters do e .......
489: Vinyl Asylum, RE: Here is another more cost effective option (0.00)
Posted by dave slagle on 2018-05-09, 17:34:47 (67.189.207.135)
they make a compelling argument and when it comes down to it I suspect the difference between 35Khz and 40Khz is trivial but the use of a frequency slightly off the typical 40Khz isn't hard and does m .......
490: Vinyl Asylum, RE: Here is another more cost effective option (0.00)
Posted by dave slagle on 2018-05-08, 06:15:37 (67.189.207.135)
Ahh the age old frequency debate. About a week ago when this cleaner was mentioned somwhere, I found a link where the designers insisted that 35Khz was the "sweet spot" for frequency to use and that .......
491: SET Asylum, RE: Which arrangement for a hybrid rectifier? (0.00)
Posted by dave slagle on 2018-04-25, 05:10:01 (67.189.207.135)
I believe that the second situation will roughly double the output voltage and the 1.4 multiplier will still be in effect for either connection if a cap input filter is used. dave .......
492: Tube DIY Asylum, RE: Current loop cap values (0.00)
Posted by dave slagle on 2018-04-16, 06:53:41 (67.189.207.135)
I typically put the last cap of the PS on the audio signal chassis so the PS will have a LCL filter with the L providing no incentive for the audio signals to ever traverse the umbilical. With a cap a .......
493: Tube DIY Asylum, RE: A PCB of Eli's phono stage (0.00)
Posted by dave slagle on 2018-04-15, 06:12:49 (67.189.207.135)
Hey, -The voltage doubler for the filaments doesn't appear to be correct the diodes are in the wrong spot. -ground planes for grounding in phono have really helped the noise for me. -using a drawing p .......
494: Tube DIY Asylum, RE: All input levels (0.00)
Posted by dave slagle on 2018-04-12, 05:06:00 (67.189.207.135)
I guess the part of this experiment I am struggling with is how to handle defining an impedance of an asymmetrically loaded signal. Lets take for example an "ideal" tube grid biased at 0V. for the + .......
495: Tube DIY Asylum, RE: All input levels (0.00)
Posted by dave slagle on 2018-04-11, 06:10:32 (67.189.207.135)
i'm looking for a way to measure the actual grid impedance. I took a 6C45 and put a 1K variable resister in the cathode to set the bias. I then figured that I could drive it with a 100mv signal and s .......
496: Tube DIY Asylum, RE: All input levels (0.00)
Posted by dave slagle on 2018-04-10, 06:45:06 (67.189.207.135)
So the sovtek 6922 has a grid Z of say 10K @ 0V and 2 meg @ -0.6V bias. Aren't these two points examples of what cannot exist with grid leak bias and all of the points inbetween become the area of int .......
497: Tube DIY Asylum, RE: All input levels (0.00)
Posted by dave slagle on 2018-04-09, 19:16:24 (67.189.207.135)
This does not occur when a tube is operating class A with a negative grid bias from external means (cathode bias or fixed bias), because grid current does not flow at idle. I was under the impressio .......
498: Tube DIY Asylum, RE: It's called "absolute phase." (0.00)
Posted by dave slagle on 2018-04-07, 18:01:35 (67.189.207.135)
Hey, But this is a case where I suspect looking at the harmonic structure of a FFT of the two positions with a microphone will produce an easily visible difference. There are a few other situations li .......
499: Tube DIY Asylum, RE: It's called "absolute phase." (0.00)
Posted by dave slagle on 2018-04-05, 19:25:48 (67.189.207.135)
hey, can you elaborate on the proof that we hear what we want to? I haven't heard a difference when flipping absolute phase in the digital domain but have heard a distinct difference when swapping spe .......
500: Tube DIY Asylum, RE: The value of the plate resistor except... (0.00)
Posted by dave slagle on 2018-04-01, 08:56:39 (67.189.207.135)
well... that was with 50p of capacitance so lets take is up to 100pf (75pf for the tube and 25pf for the associated wiring) and see what happens :-) Two different bias points... 0.6ma and 1.2ma. I .......
Found total of 500 records, Query: , Author: dave slagle in All Forums, Time: 2 sec.