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1: Tube DIY Asylum, RE: DN2540 CCS, cascade or not cascade, what you prefer? (0.00)
Posted by PakProtector on 2024-04-18, 08:52:39 (50.4.127.98)
There is magic in that box. What kind of magic? Don't know, but it may be bad. ............................................ Just trying to round up the 'omg it is solid state and that can be bad' comm .......
2: Tube DIY Asylum, CASCODE... (0.00)
Posted by PakProtector on 2024-04-18, 07:43:59 (50.4.127.98)
cascade is something different. And, whilst in there, use a DN3545N3 'under' either a 10M45 or a DN2540N5. The former is preferred for a couple reasons... :) Douglas .......
3: Tube DIY Asylum, RE: Again - Chokes Introduce Energy Storage (0.00)
Posted by PakProtector on 2024-04-17, 15:20:48 (23.125.73.217)
Bi-filar cathode transformers( vs a cap coupled choke ) do quite well indeed. I have a cascode 5687 cathode follower riding a DS cathode transformer. Sooooo simple and good as long as its lack of gain .......
4: Tube DIY Asylum, RE: my mistake, Doug. Thank you (0.00)
Posted by PakProtector on 2024-04-09, 09:01:38 (50.4.127.98)
No worries...if you'd care to examine two other similar models, the 256 amd 258, you may find it entertaining. One with a 1, 4, 9 and 16 secondary, the other with a 2, 4, 8 and 16 secondary. Same can, .......
5: Tube DIY Asylum, RE: HA! (0.00)
Posted by PakProtector on 2024-04-06, 16:37:54 (23.125.73.217)
Errr...I don't think so. The S270 is a line out, in the same can, with the same primary load as the 265. The 271 is next size up, 20-20 Plus, and can only be operated CT-grounded in 16 or 4R connectio .......
6: Tube DIY Asylum, RE: HA! (0.00)
Posted by PakProtector on 2024-04-04, 07:41:11 (50.4.127.98)
But of course. There are many of the 265's running around by now. I have a pair of 271's together on a 26HU5 amp. I did not have the two side by side for long, and was not particularly interested in .......
7: Tube DIY Asylum, HA! (0.00)
Posted by PakProtector on 2024-03-31, 02:44:44 (23.125.73.217)
I have enough trouble with the Iron...and so add significant || 'lytic value to a single big polypropylene bypass to a single stage LC filter. The Class A output stage is a nearly DC load anyway, so I .......
8: Tube DIY Asylum, but... (0.00)
Posted by PakProtector on 2024-03-28, 06:57:41 (50.4.127.98)
a large cap made of many parallel small ones will have very low esr. Douglas .......
9: Tube DIY Asylum, RE: We split phase with a tube....Can we sum to mono with a tube? (0.00)
Posted by PakProtector on 2024-02-20, 05:42:42 (50.4.127.98)
Try defining what exactly makes a stereo recording. Can you sum this signal like you suggest? I am going to bet 'NO'... But it might help if you look up a tube summing amp circuit so as to give yourse .......
10: Tube DIY Asylum, Have fun finding that many 6LF6's (0.00)
Posted by PakProtector on 2024-01-13, 14:37:10 (23.125.73.217)
They're good, but they are not inexpensive anymore. Douglas .......
11: Tube DIY Asylum, RE: What would the 12ax7 be driving? nt (0.00)
Posted by PakProtector on 2023-12-24, 09:08:47 (23.125.73.217)
A mu-follower plate load will do much for the high output impedance. Lots and lots in fact. Now if its total output voltage will be sufficient for the 300B is quite another story. It should be close I .......
12: Tube DIY Asylum, HA! (0.00)
Posted by PakProtector on 2023-12-15, 02:51:53 (50.4.127.98)
Sometimes I wish there was a like button with a RAOTFLMAO and crying icon to pick on this forum... :) Douglas .......
13: Tube DIY Asylum, Type 5687. (0.00)
Posted by PakProtector on 2023-12-14, 08:41:43 (50.4.127.98)
Try also a pair of 6AH4... Douglas .......
14: Tube DIY Asylum, errrr.... (0.00)
Posted by PakProtector on 2023-12-09, 15:17:09 (23.125.73.217)
Depends on how one defines a 'choke'. Take a grid choke. Simple, single coil. You'd need two for PP...unless you snuck both coils onto a single core and then glued the T together to make the beast on .......
15: Tube DIY Asylum, RE: Divide it Axially (0.00)
Posted by PakProtector on 2023-12-02, 16:18:52 (23.125.73.217)
An RF example: https://umiweb.com/high-voltage-winding/hv-rf-choke-1 Douglas .......
16: SET Asylum, RE: Circling back to the OP (0.00)
Posted by PakProtector on 2023-11-20, 09:01:18 (23.125.73.217)
mmmmmhhhh...plate to grid. I recall one of Gary Pimm's pictures of doing that sort of thing to a MOSFET. Resulted in vertical, evenly spaced gate lines of drain current. IMO, it is slightly easier to .......
17: SET Asylum, EL84... :) (0.00)
Posted by PakProtector on 2023-11-16, 05:43:47 (50.4.127.98)
If the gain structure is acceptable, 6V6 will have lower gain in comparable circuits. But call the plate load 10-15k Ohm, and tune the OP with their g2 voltage. Douglas .......
18: Tube DIY Asylum, RE: Never a Problem in Audio Gear (0.00)
Posted by PakProtector on 2023-11-16, 05:40:59 (50.4.127.98)
All octals are not created equal, let alone how variable the solder tab bending can be. Douglas .......
19: Tube DIY Asylum, RE: 6146 Based Tubes (0.00)
Posted by PakProtector on 2023-11-06, 09:56:03 (50.4.127.98)
Try a 2-stage amp. Pentodes everywhere. Either SE input( and thus phase splitting out of the first stage) or balanced drive. In the latter the diff amp tail load can go to a resistor to ground instead .......
20: Tube DIY Asylum, RE: I will just ask my dog... (0.00)
Posted by PakProtector on 2023-10-31, 09:11:14 (50.4.127.98)
It is not a very big triode at all. 65W plate rating. But using it zero biased, and comfortably driving its grid positive is going to yield some significant power whilst staying Class A... :) Douglas .......
21: Tube DIY Asylum, ...and (0.00)
Posted by PakProtector on 2023-10-31, 09:03:45 (50.4.127.98)
At this current, you are looking at a 'gate'-'source' voltage of about 3 Volts vs the ~1.5V for the real depletion mode MOSFET. One can also use the DN3545N3 'FET on the bottom and a 10M45 IC on top. .......
22: Tube DIY Asylum, RE: some eye candy from my stash. (0.00)
Posted by PakProtector on 2023-10-27, 16:29:33 (23.125.73.217)
mmmmmhhhh...at least two f31's there... :) Douglas .......
23: Tube DIY Asylum, RE: I will just ask my dog... (0.00)
Posted by PakProtector on 2023-10-26, 16:30:54 (23.125.73.217)
Have not built anything in a while... :) Have nearly collected the bits for the next build. And I have a new crossover to play with. Maggie says, 'it is time for a triode amp' Douglas .......
24: Tube DIY Asylum, I will just ask my dog... (0.00)
Posted by PakProtector on 2023-10-23, 17:07:55 (23.125.73.217)
She can at least get the physics right... :) and recognize when she does not know the answer. Douglas .......
25: Tube DIY Asylum, RE: Another ??? from me This time about active crossovers (0.00)
Posted by PakProtector on 2023-10-08, 17:24:56 (23.125.73.217)
Just picked up a Behringer digital; DCX2496 Ultradrive Pro. I think it can do 48dB slopes with no issue. Been working a few other projects and have not yet replaced the analog Rane AC23B yet... :) Dou .......
26: Tube DIY Asylum, circuit? (0.00)
Posted by PakProtector on 2023-09-23, 15:20:33 (23.125.73.217)
Soooo, how did you wind up using them? Have seen a screen-to-plate driving a screen to control grid... Douglas .......
27: Tube DIY Asylum, RE: Does it create risk ? Yes, yes it does. (0.00)
Posted by PakProtector on 2023-09-22, 10:03:11 (50.4.127.98)
That is part of the reason grid chokes are often suggested. At least this is not the 30k suggested for an 813 or IIRC the 10k a 50 is specified to work under. Douglas .......
28: Tube DIY Asylum, Shunt vs Biasing R (0.00)
Posted by PakProtector on 2023-09-02, 18:34:46 (23.125.73.217)
We use resistors to measure current all the time. Shunts they're called. Usually measured in the tens of mV for hundreds of amps. With tube circuits it is more like 1V/100 mA... :) Douglas ::: TOPIC:: .......
29: Tube DIY Asylum, That so-called 1%... (0.00)
Posted by PakProtector on 2023-09-01, 02:57:13 (50.4.127.98)
I believe you are also mistaken about the fraction of circuits that have no need for cathode resistance other than providing a current measuring shunt. I don't think it is going to be difficult to pro .......
30: Tube DIY Asylum, IOW, barely noticeable... :) (0.00)
Posted by PakProtector on 2023-07-17, 16:23:51 (23.125.73.217)
whilst that sounds plausible, it will be barely noticeable in any case. Douglas .......
31: Tube DIY Asylum, RE: Bringing down the ripple......? (0.00)
Posted by PakProtector on 2023-07-17, 02:40:00 (50.4.127.98)
(9) Directly-heated rectifiers greatly outperform indirect ones. Right. They conduct *NEARLY as fast as SS diodes. Their voltage drop is still high; a 5AR4 will be far more efficient and drop fewer vo .......
32: Tube DIY Asylum, RE: I use Siemens MKV Poly in Oil caps (0.00)
Posted by PakProtector on 2023-06-26, 03:17:36 (50.4.127.98)
They are quite nice. Scored two boxes of 1.5 uF/660VAC rated ones a long time ago. For two-stage amp coupling caps, they work quite nicely. Kind of large though... :) Douglas .......
33: Tube DIY Asylum, RE: I dislike PPP.... (0.00)
Posted by PakProtector on 2023-06-14, 02:39:15 (50.4.127.98)
I'm with you for the most part, but prefer Class A, along with its lower output power. The difference between 30-35W and 60 seems large, but as far as my ears go, it is not so big after all... :) Coup .......
34: Tube DIY Asylum, now why would that be? (0.00)
Posted by PakProtector on 2023-04-27, 07:55:59 (50.4.127.98)
For either topology that is? Why is clipping performance so important unless you have decided to live with an amp that does it often enough to matter? I admit that it is more an issue to the small am .......
35: Tube DIY Asylum, well... (0.00)
Posted by PakProtector on 2023-04-21, 08:49:49 (50.4.127.98)
The RCA MI-9355 is oto a decade ahead of that... :) Douglas .......
36: Tube DIY Asylum, RE: They don't. The function of the CCS (0.00)
Posted by PakProtector on 2023-04-14, 07:38:22 (50.4.127.98)
hey Ralph, try a DN3545N3 under one of the IXYS current regs. The IXYS depletion-mode-ish, TO220 thing gives about 2x the g-s voltage of a DN2540N5...so the lower MSOFET is actually running in an OP w .......
37: Tube DIY Asylum, RE: Impossible is a stretch (0.00)
Posted by PakProtector on 2023-04-08, 07:41:49 (23.125.73.217)
Maybe take that statement over to the SET forum and see what the reaction is... Have to suggest that is utterly irrelevant. However, if it indeed is, then complaints about the original statement that .......
38: Tube DIY Asylum, not us... :) (0.00)
Posted by PakProtector on 2023-04-05, 17:41:13 (23.125.73.217)
for now anyway. When I was younger, I had no place for a lifetime supply of anything. Now...who knows. And for this, I think I will laugh about it for a while longer. Good to hear from you! Douglas :: .......
39: Tube DIY Asylum, Good! (0.00)
Posted by PakProtector on 2023-04-03, 16:52:07 (23.125.73.217)
Sort of...LOL Maybe some useful but still-inexpensive tubes will remain affordable for a while longer. Have found some refreshingly inexpensive Iron on ebay from time to time recently too. Douglas ::: .......
40: SET Asylum, RE: Whoops... (0.00)
Posted by PakProtector on 2023-03-30, 00:52:42 (23.125.73.217)
I have not yet tried a GM70, but on an amp that can run both 813 and 4E27A, the 10V 813 was not humming more than the 5V Eimac. Douglas .......
41: SET Asylum, RE: Whoops... (0.00)
Posted by PakProtector on 2023-03-29, 16:58:37 (23.125.73.217)
I have not yet tried a GM70, but on an amp that can run both 813 and 4E27A, the 10V 813 was not humming more than the 5V Eimac. Douglas .......
42: Tube DIY Asylum, RE: Q: Citation2 Build-Huge Phase Inverter DC Balance Runaway (0.00)
Posted by PakProtector on 2023-03-18, 03:02:18 (23.125.73.217)
TK, follow that cathode circuit. Self biased and then the whole thing is lifted on the main tail load... :) Douglas .......
43: Tube DIY Asylum, RE: Q: Citation2 Build-Huge Phase Inverter DC Balance Runaway (0.00)
Posted by PakProtector on 2023-03-18, 02:58:13 (23.125.73.217)
I would trim their g2 voltage a wee bit. My W6m's run a very similar pentode front end and none ever give me fits as long as I manage their screen grid voltage. Douglas .......
44: Tube DIY Asylum, RE: NFB in a PP DHT amp? (0.00)
Posted by PakProtector on 2023-03-14, 04:30:33 (50.4.127.98)
Is more than one way to do NFB. No loop for me. Now, if we could separate drive signal from NFB signal... -say, drive the cathode and apply NFB to g1. Douglas .......
45: Tube DIY Asylum, hot dog... (0.00)
Posted by PakProtector on 2023-02-18, 17:16:55 (23.125.73.217)
we have a wiener... :) Douglas .......
46: Tube DIY Asylum, Oh no.... (0.00)
Posted by PakProtector on 2023-02-18, 04:03:20 (23.125.73.217)
McIntosh amps, pre-amps, and their associated components and circuits are PERFECT. There is no way to improve upon them. Anything you do will hurt re-sale and ruin the sonics. Douglas .......
47: Tube DIY Asylum, That is about it... :) (0.00)
Posted by PakProtector on 2023-02-08, 03:25:57 (50.4.127.98)
And of course go a step along this path and use the heater winding of the now-missing pair of EL34 and run a pair of damper diodes... Douglas .......
48: Tube DIY Asylum, RE: NFB in a PP DHT amp? (0.00)
Posted by PakProtector on 2023-02-03, 03:19:20 (50.4.127.98)
Ummmmm...I have to say that NFB does not need to result in such behaviour. I agree with not doing things to cause the characteristics you describe, and I would love to have you hear some amps with NFB .......
49: Tube DIY Asylum, RE: NFB in a PP DHT amp? (0.00)
Posted by PakProtector on 2023-01-30, 06:49:56 (50.4.127.98)
For the most part I have found the output Z reduction the most important benefit about NFB. Hooking NFB up will reduce delivered gain. Will you like it? That is a fair question... :) Don't have an ans .......
50: Tubes Asylum, RE: Jaded? Neither, I am . . (0.00)
Posted by PakProtector on 2023-01-02, 16:04:08 (23.125.73.217)
I regret not buying more of them when I could. They are quite nice. Douglas .......
51: Tube DIY Asylum, RE: New amp (0.00)
Posted by PakProtector on 2023-01-02, 15:15:39 (23.125.73.217)
Find Gary Pimm's work. The full MOSFET ones... :) Douglas .......
52: Tube DIY Asylum, RE: I would have to see that. nt (0.00)
Posted by PakProtector on 2022-12-27, 14:31:16 (23.125.73.217)
a thread like 'pentode revenge' or something like that. Drive the cathode, and apply plate FB to g1. Separate drive from FB seems not without its charm...but just some plate-to-grid does a very fine j .......
53: Tube DIY Asylum, LOL... (0.00)
Posted by PakProtector on 2022-12-26, 13:50:44 (23.125.73.217)
There are others... :) HY51A for example. 845 for another. That said, examine what can be done to a KT88( or a sweep, or... )with some FB. The resulting triode curves make the 300B look remote cut-off .......
54: Tube DIY Asylum, RE: A possibly different perspective on the matter (0.00)
Posted by PakProtector on 2022-12-25, 03:23:21 (23.125.73.217)
hey-Hey!!!, That one is 450V and 40% U-L tapping. Those are the two bits that matter IME. How that goes together with the tube of choice is quite another story. Output Iron is all over the place, even .......
55: Tube DIY Asylum, RE: Push pulll transformer question (0.00)
Posted by PakProtector on 2022-12-20, 06:50:38 (50.4.127.98)
Very likely you did. Probably was showing a stereo DH amp. 1619's I think with 6AU6 front end. Steve knows how to put on a GTG... :) fine brisket. Douglas .......
56: Tube DIY Asylum, RE: It's been done (0.00)
Posted by PakProtector on 2022-12-18, 17:15:35 (23.125.73.217)
and Gary Pimm did a full-on SS variant of his PP47 amp with cascode mosfet blocks instead of pentodes. Douglas .......
57: Tube DIY Asylum, RE: Push pulll transformer question (0.00)
Posted by PakProtector on 2022-12-18, 14:58:39 (23.125.73.217)
AB of course is a combo of the two. run a-a/2 until current is about 2x the idle, then turn it up to a-a/4. There will be no discontinuity, but instead a curve( the cut-off is not immediate on the one .......
58: Tube DIY Asylum, the explain (0.00)
Posted by PakProtector on 2022-11-22, 07:59:15 (50.4.127.98)
am now older, and have less hearing capability than when I started this stuff 2 decades ago... :) Douglas .......
59: Tube DIY Asylum, RE: And yet... (0.00)
Posted by PakProtector on 2022-11-14, 01:38:06 (23.125.73.217)
That meant a whole lot more when I first signed up for this forum than it does now... :) Douglas .......
60: Tube DIY Asylum, RE: I have this one in the pipeline RH-6080 (0.00)
Posted by PakProtector on 2022-10-30, 14:23:46 (23.125.73.217)
Now ditch the 12AT7 for a 6AU6 and you'll be in business. Not plagued by a variable NFB level due to varying plate resistance. Douglas .......
61: SET Asylum, RE: no 200 watt SET midlife crisis coming your way? (0.00)
Posted by PakProtector on 2022-10-14, 16:13:22 (23.125.73.217)
No 200W tube amp crisis is going to happen... :) SE or otherwise. Douglas .......
62: Tube DIY Asylum, RE: Energy prices out of control may put at risk tube amplifiers (0.00)
Posted by PakProtector on 2022-10-14, 08:55:38 (50.4.127.98)
Dennise, somebody is going to go to the trouble of lighting filaments of a few DH tubes and hide a SS amp under the chassis and fool you. If that event had any value it would already have happened. c .......
63: SET Asylum, RE: only one person - that's funny (0.00)
Posted by PakProtector on 2022-10-11, 01:22:34 (23.125.73.217)
Won't say never, but effectively...NO, not going to put any effort into building/owning a SET. So I can probably extend the 2.2 decades I have been building PP amps... :) Douglas .......
64: Tube DIY Asylum, RE: Your opinion of the 6CG7 (0.00)
Posted by PakProtector on 2022-09-27, 10:18:13 (50.4.127.98)
IFF you pin for 6CG7, you can make use of the 6H6Pi which I far prefer to the 6CG7. Gain is comparable, but plate resistance is lower. cheers, Douglas .......
65: Tube DIY Asylum, missing (0.00)
Posted by PakProtector on 2022-09-27, 07:30:55 (50.4.127.98)
There is nothing missing. We have learned it all. The list is endless, but I will remind y'all of a few important ones. 1. A PP output tx can only present a quarter of its a-a loading to one tube( of .......
66: Tubes Asylum, RE: Repairing damaged trace on circuit board (0.00)
Posted by PakProtector on 2022-08-01, 09:32:41 (50.4.127.98)
I have soldered in a bit of solder wick. Not ideal...but still functional after nearly a quarter of a century... :) Douglas .......
67: Tube DIY Asylum, Ha! 'much less' (0.00)
Posted by PakProtector on 2022-07-11, 08:22:39 (50.4.127.98)
Seems a matter of opinion...compared to something else triod-ed? maybe I have for sure seen worse 'very close' comparisons. Mu is comparable, as is moderate current plate resistance. Swap and have it .......
68: Tube DIY Asylum, RE: Of course you're right. I have more brain farts there days. Sorry. Thanks. (0.00)
Posted by PakProtector on 2022-07-08, 01:34:32 (23.125.73.217)
I usually have to draw liddle arrows on the schematic to figure that stuff out... :) Douglas .......
69: Tube DIY Asylum, RE: How can A2 happen in 845 (0.00)
Posted by PakProtector on 2022-06-29, 03:15:38 (50.4.127.98)
Do consider what the plate voltage will be when the grid goes from +25 to +50. I suspect it will be lots lower than 1kV. Takes both the plate curves and the grid current curves to get a handle on this .......
70: Tube DIY Asylum, RE: How can A2 happen in 845 (0.00)
Posted by PakProtector on 2022-06-28, 17:05:08 (23.125.73.217)
I like the idea of a consistent load. For the tubes I have in mind( HY51A), the 'difficult' grid is difficult half the time the way I intend to run it( 0 bias, or very close to it), and of course PP a .......
71: Tube DIY Asylum, RE: 12b4a nt (0.00)
Posted by PakProtector on 2022-06-27, 16:08:52 (23.125.73.217)
and then 7233...and the Russian 6C19Pi... cheers, Douglas .......
72: Tube DIY Asylum, RE: what twin triode IDH tube is the least amplification factor? I only need something like 8 (0.00)
Posted by PakProtector on 2022-06-25, 06:50:13 (23.125.73.217)
Type 6BX7 comes to mind. Douglas .......
73: Tube DIY Asylum, RE: How can A2 happen in 845 (0.00)
Posted by PakProtector on 2022-06-20, 17:23:53 (23.125.73.217)
It becomes entertaining when the plate voltage is low, and the grid current goes up, so the condition where the grid impedance is being calculated matters. So... So to heck wid driving the grid. Groun .......
74: SET Asylum, RE: cost of SET (0.00)
Posted by PakProtector on 2022-06-06, 15:34:58 (23.125.73.217)
The first DH amp I ever built was with 1619's. U-L rigged with a B+ of ~270V. Dynaco Z565 for OPT's. The front end was a 6AU6 LTP hooked up E-Linear to the UL taps. I brought it to a Bottlehead meet .......
75: Tubes Asylum, RE: Bringing it up with a 5AR4 wont get you there. (0.00)
Posted by PakProtector on 2022-06-03, 08:49:45 (50.4.127.98)
The slightly easier way is to just plug in something else. a 5Y3 for instance, and some 6V6's or perhaps cheap 6L6's. Goal is not to get full performance, but reach 75% of B+ and deliver some idle cur .......
76: Tube DIY Asylum, RE: The suppressor grid is not totally floating (0.00)
Posted by PakProtector on 2022-05-06, 04:01:37 (50.4.127.98)
For horizontal outputs, getting the suppressor above cathode by ~30V reduced a TV specific sort of distortion. Not quite sure what 'snivets' sound like, but for video, they're not wanted... :) cheers, .......
77: Tube DIY Asylum, Langvin gear (0.00)
Posted by PakProtector on 2022-04-26, 16:13:03 (23.125.73.217)
Hey Tre' was that Langvin mic pre skinny, with a pair of TX's on top? full rack loaded Cannon connector for power, filament and signal? The 6V6 amps I found with 'em had an input TX and two signal pen .......
78: Tube DIY Asylum, oooohhhh....that sounds really bad (0.00)
Posted by PakProtector on 2022-04-15, 16:52:27 (23.125.73.217)
"The problem with using balanced with tubes is no two tubes have ever been built that are even remotely alike. That statement is much more true today, where we find that mechanical tube variations are .......
79: Tube DIY Asylum, RE: Guess I have to make one of your amps (0.00)
Posted by PakProtector on 2022-04-14, 10:11:59 (23.125.73.217)
That is probably what they'll say. Another topic to search would be, 'i built it and it sux', and take note of their responses. What ever they said is responsible for it not turning out 'right' is wh .......
80: Tube DIY Asylum, RE: Imma gonna whip something up this year..with this in mind ...nt (0.00)
Posted by PakProtector on 2022-04-13, 16:11:28 (23.125.73.217)
Two stage should be adequate. As Ralph noted, balanced input. Do the heavy lifting in the linestage with a LTP perhaps. cheers, Douglas .......
81: Tube DIY Asylum, on the TX choice... (0.00)
Posted by PakProtector on 2022-04-13, 09:39:40 (50.4.127.98)
Let's build around the 8k pair of pairs. Instability won't be much of an issue 'cause there will be no global NFB. Any taps? if so, what is the percentage? cheers, Douglas .......
82: Tube DIY Asylum, RE: 9k9 amorphous core. 6k6 and two 8k one EI one double C (0.00)
Posted by PakProtector on 2022-04-13, 04:56:17 (96.27.154.226)
IDK about the 173 phase splitting choke. I have only heard them in a PP 2A3 amp, and those got retired by an E-Linear 807 build... :D cheers, Douglas .......
83: Tube DIY Asylum, with an estimate of speaker sensitivity... (0.00)
Posted by PakProtector on 2022-04-11, 17:30:50 (23.125.73.217)
I want a whole pile of linear, from-the-middle-of-the-curves, POWER. If you have never gotten a dose of it, I can see the means to convince one's self it is not needed... :) cheers. Douglas ::: TOPIC .......
84: Tube DIY Asylum, RE: Guess I have to make one of your amps (0.00)
Posted by PakProtector on 2022-04-11, 14:45:13 (23.125.73.217)
Well Bas, I'll help as you ask. What outputs have you got pairs of? And of course, a choice for you: you can get the help here, in public, in private, or in some combination...how ever you prefer. Yo .......
85: Tube DIY Asylum, RE: Opinions wanted re: Jac Music 6EM7-300B (0.00)
Posted by PakProtector on 2022-04-11, 07:55:49 (96.27.154.226)
Implementation...yes. Especially if a pentode driver is used. Can be really good, but mismanage/mis-match g2 voltage to the load and all bets are off. cheers, Douglas .......
86: Tube DIY Asylum, RE: None of my pp amps are a succes... (0.00)
Posted by PakProtector on 2022-04-11, 06:41:53 (96.27.154.226)
The only times I have liked SE over PP was for instrument amps. Beyond that, the SE fingerprints totally drive me bonkers. Class A PP, which only gets me 3dB over SE... cheers, Douglas .......
87: Tube DIY Asylum, RE: 2a3 amp (0.00)
Posted by PakProtector on 2022-04-09, 15:41:48 (23.125.73.217)
Get out more...read some folk like Gary Pimm. You will discover you have been misled( rather common these days unfortunately ). cheers, Douglas .......
88: Tube DIY Asylum, RE: That depends (0.00)
Posted by PakProtector on 2022-04-08, 08:20:29 (96.27.154.226)
There is more to it that you currently realize TK, and whilst all use some SS, not all require a full ccs. And Output Z can be quite a bit lower... :) cheers, Douglas .......
89: Tube DIY Asylum, That depends (0.00)
Posted by PakProtector on 2022-04-04, 05:48:21 (96.27.154.226)
The pentode section can indeed deliver more output at lower distortion IFF the ccs is used carefully. The PI section will not benefit from one current reg, unless it is changed to a LTP. This is not t .......
90: Tube DIY Asylum, RE: 2a3 amp (0.00)
Posted by PakProtector on 2022-03-31, 03:45:26 (50.4.127.98)
wiring is not a 'high loss' part of these constructions. I suppose it would be possible to make it so with great effort...say, use ni-chrome where copper is called for. It is a convenient point for .......
91: Tube DIY Asylum, not at all.... (0.00)
Posted by PakProtector on 2022-03-28, 04:12:05 (50.4.127.98)
recall that dennis is building a tuned up effects box. The so-called 'issues' that you point out Tre' are just the means to that end. Sprinkle liberally with transfer efficiency, and you wind up with .......
92: SET Asylum, RE: Plate load resistors +1 (0.00)
Posted by PakProtector on 2022-02-18, 16:57:00 (23.125.73.217)
"if they were available"...yep, that is certainly about the size of it. Would love to be able to get 'em from Mouser. Douglas .......
93: SET Asylum, OK (0.00)
Posted by PakProtector on 2022-02-14, 10:02:14 (96.27.154.226)
So how long did it take you to get to a decision making point? and, making a prediction here, why is it so short compared to what you suggest to the OP? All that aside, before building an ultimate amp .......
94: SET Asylum, RE: Plate load resistors (0.00)
Posted by PakProtector on 2022-02-13, 15:37:52 (23.125.73.217)
They're bigger than the 1W Holco( which should be treated like 1/2W in order to keep 'em from getting noisy). Am not a fan of colourful components, there were super low L Mills, at perhaps 3W rating a .......
95: SET Asylum, RE: We don't need "an agreement" - just suggestions (0.00)
Posted by PakProtector on 2022-02-13, 13:21:51 (23.125.73.217)
That 'best parts' is way too deep a rabbit hole. Add to that no common listening experience... LOL But anyway...coupling caps ought to be Teflon dielectric, and foil electrode. Couple to choose from t .......
96: SET Asylum, Not even going to get an agreement on parts selection (0.00)
Posted by PakProtector on 2022-02-13, 11:11:42 (23.125.73.217)
then you can go worry about a 2A3 or one of the 2A3 with additional plate dissipation. And then... cheers, Douglas .......
97: Tube DIY Asylum, RE: I think you have not changed ... (0.00)
Posted by PakProtector on 2022-02-11, 04:28:23 (96.27.154.226)
Expecting you to explain yourself is 'stalking'? Questioning your ridiculous claims about things like 'transfer efficiency' is stalking? How quaint... :) cheers, Douglas .......
98: Tube DIY Asylum, First... .0755A is 75.5 mA (0.00)
Posted by PakProtector on 2022-02-09, 17:01:10 (23.125.73.217)
not uA or micro-Amp. cheers, Douglas .......
99: SET Asylum, RE: cost of SET (0.00)
Posted by PakProtector on 2022-02-09, 15:03:32 (23.125.73.217)
That is one way to look at it Dave. Have to define the comparison...and that leaves it wide open more or less. Simplest? Power within a dB? Same tubes( need to define 'same' ). So build the comparison .......
100: Tube DIY Asylum, yep...backwards (0.00)
Posted by PakProtector on 2022-02-09, 14:46:05 (23.125.73.217)
There is nothing magical, except for your sales pitch we have heard waaaaaaay too many times. cheers, Douglas .......
101: Tube DIY Asylum, I think you have it backwards.... (0.00)
Posted by PakProtector on 2022-02-09, 09:14:31 (96.27.154.226)
The wailing is from your side. As demonstrated by the post this one follows. You make non-sensical claims about demonstrably effects box designs, and when met with, 'I don't think so there happybear.. .......
102: Tube DIY Asylum, RE: You forgot a wee bit... (0.00)
Posted by PakProtector on 2022-02-09, 07:30:37 (96.27.154.226)
It is a matter I think of the peak repetitive current. Think for a few minutes about breaking one when they are hot and hopefully induce some paranoia... :) Am tempted to say, probably not a good idea .......
103: Tube DIY Asylum, You forgot a wee bit... (0.00)
Posted by PakProtector on 2022-02-08, 17:12:35 (23.125.73.217)
At the time, you were espousing one combination after another of various inductors. One after the other, each more perfect than the last. Then Henry dug into one of them and described how it worked. T .......
104: Tube DIY Asylum, RE: I did fail to include that short comming. (0.00)
Posted by PakProtector on 2022-02-08, 16:53:12 (23.125.73.217)
2022 Power tube: HY51A. Idling at 60/65ths of its plate rating. Class A PP, cathode drive...on a 10k a-a load. I anticipate its making enough power to push an S-265-Q to its limits when made with dece .......
105: Tube DIY Asylum, back to our regurly scheduled effects box worship... :) (0.00)
Posted by PakProtector on 2022-02-08, 09:44:21 (96.27.154.226)
have fun wid that hb... :) Douglas .......
106: Tube DIY Asylum, I think ya forgot a feature (0.00)
Posted by PakProtector on 2022-02-08, 09:37:04 (96.27.154.226)
the partially bypassed cathode. Does wonders for the tone... LOL cheers, Douglas .......
107: Tube DIY Asylum, Having some trouble finding something happybear? (0.00)
Posted by PakProtector on 2022-02-08, 01:35:48 (23.125.73.217)
I was hoping to hear you had discovered some proof I was mistaken. cheers, Douglas .......
108: Tubes Asylum, RE: My method works with a single whack.... (0.00)
Posted by PakProtector on 2022-02-07, 16:04:16 (23.125.73.217)
Yah...50 BMG is no joke. Was going to head to Philly one spring afternoon in 1985 to spectate at the Move fiasco, and just as I was about to pick up my helmet, the news guy says they brougt in a 50 ca .......
109: Tube DIY Asylum, RE: the credibility was established at RMAF ... (0.00)
Posted by PakProtector on 2022-02-07, 14:51:13 (23.125.73.217)
Bah! got ticketed at nearly that much over. cheers, Douglas .......
110: Tubes Asylum, RE: Selling from NY area? (0.00)
Posted by PakProtector on 2022-02-06, 17:28:52 (23.125.73.217)
SE Michigan is a fine place to deal in tubes; lots of enthusiasts. cheers from Ypsi, Douglas .......
111: Tube DIY Asylum, RE: RE :answer the call of greatness (0.00)
Posted by PakProtector on 2022-02-06, 16:23:49 (23.125.73.217)
"On Tube DIY is one of the greatest resources of SE tube amp knowledge in the history of this hobby, DF." errr...I am truly confused by this statement. I have yet to see him give any instruction on ho .......
112: Tube DIY Asylum, RE: the "concepts" are not defects ... (0.00)
Posted by PakProtector on 2022-02-06, 15:14:14 (23.125.73.217)
To hell with answering the call to greatness...would be quite happy if questions regarding outlandish claims were answered with something other than nonsense. oooohhh...transfer efficiency, that sound .......
113: Tubes Asylum, RE: My method works with a single whack.... (0.00)
Posted by PakProtector on 2022-02-05, 18:07:55 (23.125.73.217)
If you were out in the country, a 25gr, 25 cal pellet from a pneumatic rifle is quite effective too. In town, not so much... :) Plinkers can make one heck of a mess; it is not recommended to have 'em .......
114: Tube DIY Asylum, RE: Subjective Criteria, and the word " defect " (0.00)
Posted by PakProtector on 2022-02-05, 08:11:16 (23.125.73.217)
OK, sets of combined defects. For instance, inadequate cathode bypassing. Output Z varies with frequency, and even position on the waveform. That is audible. And, 'no thanks', not for me... That some .......
115: SET Asylum, RE: cost of SET (0.00)
Posted by PakProtector on 2022-02-05, 07:56:03 (23.125.73.217)
HA! Cost? On a per-watt basis it at least 2x PP. Same PS cost, same OPT iron cost, and for Class A PP as a comparison, SE delivers half the power. Like you said Paul, rectifiers, filter, and component .......
116: Tube DIY Asylum, RE: Subjective Criteria (0.00)
Posted by PakProtector on 2022-02-05, 03:22:35 (23.125.73.217)
It could be that measures bad, sounds good is acceptable. It is more likely that a particular passage/song/set is going to sound good on such a machine. Care to bet that all music will be improved by .......
117: Tube DIY Asylum, RE: Why yes... (0.00)
Posted by PakProtector on 2022-02-04, 16:14:18 (23.125.73.217)
You will have to make your own opinion. I doubt you'll hate them. cheers, Douglas .......
118: Tube DIY Asylum, Why yes... (0.00)
Posted by PakProtector on 2022-02-04, 14:48:59 (23.125.73.217)
6V6GTA make a very fine voltage amp. So does the 6AQ5. Indistinguishable actually. High eff speakers are useful for many reasons. I have been listening to such beasties(high eff of *excellent* qualit .......
119: Tube DIY Asylum, RE: linear design ... (0.00)
Posted by PakProtector on 2022-02-04, 07:51:56 (50.4.127.98)
Idle current is only a slice of the equal clipping process. It is of course the lowest fruit and as you note, not without cost. Tube life is a worry-free item for me; don't care about it at all. It is .......
120: Tube DIY Asylum, RE: 15uF ... main bypass cap value for SE amplifiers (0.00)
Posted by PakProtector on 2022-02-04, 05:39:06 (50.4.127.98)
Correcting a design with FB is less-than-ideal. Keep in mind, I have no use for cathode bypass, or SE, but it should be obvious that the NFB is responsible for your measured performance, and that you .......
121: Tube DIY Asylum, RE: Output impedance (0.00)
Posted by PakProtector on 2022-02-04, 04:02:20 (50.4.127.98)
When I was developing exhaust systems, GTPower would let you listen to the results in a similar fashion. This of course depended on the engine model, but those complex, tuned up files were provided by .......
122: Tube DIY Asylum, RE: standard engineering formula (0.00)
Posted by PakProtector on 2022-02-03, 16:02:00 (23.125.73.217)
don't forget the transfer efficiency. Douglas .......
123: Tube DIY Asylum, Oh my... :) (0.00)
Posted by PakProtector on 2022-02-03, 14:36:52 (23.125.73.217)
that sums it up pretty well. check out Dave's output Z plot. shows this happening. Would of course be neat to show the effect with a few different values of bypass cap. cheers, Douglas .......
124: Tube DIY Asylum, RE: Output impedance (0.00)
Posted by PakProtector on 2022-02-01, 15:41:01 (23.125.73.217)
Ya build it with vetted model bits. Bits that do what you think they should, how they should be done. Then it is relatively easy to be sure nothing foolish is going on when you being the whole amp mod .......
125: Tube DIY Asylum, HA! (0.00)
Posted by PakProtector on 2022-02-01, 09:59:15 (50.4.127.98)
Those suggestions provided more proof to the claim you have told us how your amps actually perform. Effects box, IOW. Thanks. I hope you have read the completed study on why worm medicine looked promi .......
126: Tube DIY Asylum, RE: Output impedance (0.00)
Posted by PakProtector on 2022-02-01, 09:49:49 (50.4.127.98)
So what is the LF peak from, inadequately bypassed cathode? cheers, Douglas .......
127: Tube DIY Asylum, Why is that?.. (0.00)
Posted by PakProtector on 2022-01-31, 13:20:58 (23.125.73.217)
I know that the trip will show me an effects box. You and he have both said it will. repeatedly. As far as 6005 goes, there is one fine signal amplifier right there. Along with many other small power .......
128: Tube DIY Asylum, hmmmm.... (0.00)
Posted by PakProtector on 2022-01-30, 11:09:45 (23.125.73.217)
Looks like a step backwards to me. Several actually. What your magical, mystical, 'mlp' is about has been adequately documented as an effects box. it is obvious they've found their niche of folk who l .......
129: Tube DIY Asylum, RE: forget it ... (0.00)
Posted by PakProtector on 2022-01-30, 04:25:56 (23.125.73.217)
LMAO... let's see, perhaps a review of history. Some idiot says, 'this is the way to build the best amp'. An inmate or three applies the instructions, gets a predictably poor result, and gets blamed b .......
130: Tube DIY Asylum, RE: parallel SE 6005 ... (0.00)
Posted by PakProtector on 2022-01-29, 14:22:27 (23.125.73.217)
Only serious about making a bet you'd lose. Proven how and what I build since before you recognized the need to become a fanboy. Besides, I have never seen any of your bosses say anything good about P .......
131: Tube DIY Asylum, RE: OK, Pak ... (0.00)
Posted by PakProtector on 2022-01-28, 05:40:58 (50.4.127.98)
You neglect the first condition... :) SO far all the evidence I see indicated it is not something he can meet. Douglas .......
132: Tube DIY Asylum, RE: he is the "alpha" ... (0.00)
Posted by PakProtector on 2022-01-27, 16:04:14 (23.125.73.217)
Tell you what, as soon as I see him write something that makes sense, and gives the detailed instructions to build one of his creations, I'll build one to print. If I like it, I will never do anything .......
133: Tube DIY Asylum, RE: it is true .. the facts speak for themselves (0.00)
Posted by PakProtector on 2022-01-27, 15:31:09 (23.125.73.217)
followers are not alpha's. They are followers...and we have seen all too clearly that it is remarkably easy to lead people around by the nose by repeating things often enough and loudly enough. cheers .......
134: Tube DIY Asylum, let me tranlsate (0.00)
Posted by PakProtector on 2022-01-26, 10:16:18 (50.4.127.98)
Denis has mastered a Marketing Spiel full of words that, in context mean NOTHING. In several years, we will discover they mean nothing( actually, we already know they mean nothing ). That is not going .......
135: Tube DIY Asylum, RE: it's not about measured performance ... (0.00)
Posted by PakProtector on 2022-01-26, 10:10:52 (50.4.127.98)
and what you don't seem willing to grasp is that their niche is that of effects boxes, and there are lots more people who want The Real Thing instead of HD-modified dreck. It would not matter at all i .......
136: Tube DIY Asylum, RE: The best way to use feedback (0.00)
Posted by PakProtector on 2022-01-23, 15:24:29 (23.125.73.217)
Well, I have tried some of what you claim to be The Way. Like deciding that a pentode linestage loaded with a 500 Ohm plate load worked well. A quick FFT showed why it was so dramatically different: l .......
137: Tubes Asylum, RE: Mostly radio and TV tubes......... (0.00)
Posted by PakProtector on 2022-01-21, 13:01:33 (23.125.73.217)
Oh my goodness...'radio and TV tubes' dismisses a large pile of very useful tubes. Type 6AH4 is a TV tube...very tasty for audio work. Same with a tube built for similar function, type 25HX5. I'll not .......
138: Tube DIY Asylum, RE: The best way to use feedback (0.00)
Posted by PakProtector on 2022-01-20, 07:50:26 (50.4.127.98)
Ralph, I have to ask, why use NFB to reduce gain? WHy not just build in less? Lower output Z, oh yes. Linearize it, some, but definitely not so critical IME. cheers, Douglas .......
139: Tube DIY Asylum, RE: Looking for simple fully balanced 6BQ5 schematic (0.00)
Posted by PakProtector on 2022-01-19, 15:34:50 (23.125.73.217)
As to part of Ralph's response, build it linear. I don't agree on the 'gaiin reduction' bit. That can be what ever it needs to be( more or less), but the output Z is the bit it is quite good for. You .......
140: Tube DIY Asylum, RE: Looking for simple fully balanced 6BQ5 schematic (0.00)
Posted by PakProtector on 2022-01-18, 17:55:06 (23.125.73.217)
The grounded grid side is the usual way to stick NFB into an LTP. however, do away with the global loop. Plate to grid with a pentode LTP. EL84 would be a fine choice... :) cheers, Douglas ::: TOPIC:: .......
141: Tube DIY Asylum, it was a freebie (0.00)
Posted by PakProtector on 2022-01-17, 15:00:53 (23.125.73.217)
in the transfer efficiency sack. cheers, Douglas .......
142: Tube DIY Asylum, RE: world class ... (0.00)
Posted by PakProtector on 2022-01-16, 15:39:21 (23.125.73.217)
Doood...your 'facts' are clearly different from Facts. I believe one of yours coined the modifier, 'alternative' just for that sort of thing. This goes entirely right past the idea that not everybody .......
143: Tube DIY Asylum, nah... (0.00)
Posted by PakProtector on 2022-01-16, 03:46:46 (23.125.73.217)
If you look at what denise writes, she is a god unto herself. There are plenty of supporters who indulge that fantasy. It does not really matter; I know enough not to chase after such foolishness. che .......
144: Tube DIY Asylum, RE: Well you measured it. (0.00)
Posted by PakProtector on 2022-01-15, 09:20:28 (23.125.73.217)
Probably because you are tuning a global FB loop. That and your applied, 'no silicon' principle. Try changing the philosophy and avoid the first one, and ignore the second... :D cheers, Douglas ::: TO .......
145: Tube DIY Asylum, RE: it is serious, Pak ... (0.00)
Posted by PakProtector on 2022-01-15, 09:16:31 (23.125.73.217)
I would not contemplate troubling Dave G. Probably would include BGE as long as I never saw them write something foolish like 'transfer efficiency'. You, otoh, who apply that term to stuff from so-cal .......
146: Tube DIY Asylum, Don't take it so seriously... (0.00)
Posted by PakProtector on 2022-01-14, 03:15:57 (50.4.127.98)
Lots of folks who don't know what they're doing say things are "world class". cheers, Douglas .......
147: Tube DIY Asylum, and... (0.00)
Posted by PakProtector on 2022-01-07, 18:56:17 (23.125.73.217)
With the high output Z driver, it would not matter if it was 300% efficient, it still would not go full bandwidth. So maybe it is only 150% efficient? Probably only about 143.5% if he were to measure .......
148: Tube DIY Asylum, RE: why? ... (0.00)
Posted by PakProtector on 2022-01-06, 15:44:41 (23.125.73.217)
Love the quotes. Appropriately used. cheers, Douglas .......
149: Tube DIY Asylum, RE: MSEE? (0.00)
Posted by PakProtector on 2021-12-30, 11:02:17 (23.125.73.217)
Like when Tucker set up a show across from an SAE gathering. Velvet ropes went up and nobody got near it. Just earlier fraud... LOL cheers, Douglas .......
150: SET Asylum, RE: The best preamp is no preamp (0.00)
Posted by PakProtector on 2021-12-26, 13:58:11 (23.125.73.217)
It is easy; the momo-blocks do not have the gain by themselves. The linestage has only jus' enough plus a little. It drives the low-ish input stage resistor 'cause that sounds more natural. Lower is b .......
151: SET Asylum, RE: A watt is a watt! (0.00)
Posted by PakProtector on 2021-12-26, 07:00:01 (23.125.73.217)
Oh my... I can put a Watt into the air. There is no way one of these fantasy amps that puts 1 Watt into the voice coil terminals is going to deliver that. I assume at some point you will discover you .......
152: Tubes Asylum, Cool. (0.00)
Posted by PakProtector on 2021-12-25, 09:21:49 (23.125.73.217)
The sooner the new gang of wacko's stops hoarding tubes, cause they're tubes, the better. If BC can convince some of them that valve amps bite, good on him... :) cheers, Douglas .......
153: Tube DIY Asylum, Thanks Denis... :) (0.00)
Posted by PakProtector on 2021-12-23, 17:02:32 (23.125.73.217)
I do believe the proper path forward is going to be doing exactly the opposite of what your suggesting. Thanks for the early present. Time smearing...and there is a War on Christmas. They go right tog .......
154: Tube DIY Asylum, RE: Exploring ONGAKU 2nd VAS design - local feedback (0.00)
Posted by PakProtector on 2021-12-21, 03:48:07 (50.4.127.98)
Seems like there is gain to spare...6072 stages feeding 5687 stages. Gain beyond the ability of the last driver stage to swing it I'd think. Ground the 211's grid and drive its cathode... :) cheers, D .......
155: Tube DIY Asylum, RE: Altec 1570B mods (0.00)
Posted by PakProtector on 2021-12-14, 14:22:11 (23.125.73.217)
If I had one, I would most certainly modify it. The basics are there to do a lot. It can be a fairly solid 60-70W hi-fi amp with a bit of headroom if you stay away from the low frequency end( check ou .......
156: Tube DIY Asylum, What? (0.00)
Posted by PakProtector on 2021-12-14, 14:18:53 (23.125.73.217)
The basic unit is mostly a Class B amp... then (don't push it into Class B!- I suppose it could have made sense when you had the thought, but what you wrote, not so much. cheers, Douglas .......
157: Tube DIY Asylum, RE: How to Reduce Signal from Pre-Amp to Amps ............... (0.00)
Posted by PakProtector on 2021-12-09, 04:14:17 (50.4.127.98)
I have crossovers that include output level adjustment. It is for a tri-amp set up. It is a Rane AC23B. cheers, Douglas .......
158: Tube DIY Asylum, RE: Additional details... (0.00)
Posted by PakProtector on 2021-12-02, 01:24:23 (23.125.73.217)
Why not use cheap, octal dampers. The worst among them have more capacity and less drop than a 5R4. cheers, Douglas .......
159: Tube DIY Asylum, RE: Cathode Stripping (0.00)
Posted by PakProtector on 2021-12-01, 15:47:56 (23.125.73.217)
So if it is longevity you seek, how many times is cathode voltage right on spec? I have no issue going to some trouble to achieve this... :) I don't mind tweaking things every now and then...some cust .......
160: Tubes Asylum, RE: 574B (0.00)
Posted by PakProtector on 2021-11-30, 07:24:40 (50.4.127.98)
The 274 was more of a 5R4 anyway. IOW, not much peak current capacity, but able to tolerate more PIV. Check the specs per the usage, and if it is a modern 'approximation' use some caution... :) cheers .......
161: Tubes Asylum, RE: 300b amps (0.00)
Posted by PakProtector on 2021-11-27, 16:57:09 (23.125.73.217)
Filament voltage is important also... :) Not sure what I'd sacrifice first, and in truth it has never come up. My first DH amp happened to get a TX that worked out OK. The second got a small variac on .......
162: Tube DIY Asylum, RE: Recent Project Completed (0.00)
Posted by PakProtector on 2021-11-23, 17:45:59 (23.125.73.217)
Nice work there. A bit light on Iron for my personal stuff, but this clearly isn't that. By its specs, the output iron is doing its job. Do try that one with a LTP front end and some local FB instead .......
163: Tube DIY Asylum, RE: "AMPLIFIER DESIGNS FOR REDUCED IMD" (0.00)
Posted by PakProtector on 2021-11-23, 15:40:10 (23.125.73.217)
That may be so...but I'd like to see this recipe capable of reducing IMD. I do not think it it impossible to use pentodes and have nearly none. cheers, Douglas .......
164: Tube DIY Asylum, RE: "AMPLIFIER DESIGNS FOR REDUCED IMD" (0.00)
Posted by PakProtector on 2021-11-23, 01:53:21 (23.125.73.217)
Why is this mattering? Assume it is 80 dB. That still represents a trivial percentage of total amplifier output. The infinite baffle efficiency of the drivers are all high 90 dB's( 1W-1m ), and they'r .......
165: Tube DIY Asylum, RE: "AMPLIFIER DESIGNS FOR REDUCED IMD" (0.00)
Posted by PakProtector on 2021-11-22, 15:36:58 (23.125.73.217)
Apply some NFB, and the pentode develops some very fine triode curves. Assume where this is going, and how is that pentode compared to a triode which is not capable of such linear curves open loop? ch .......
166: Tube DIY Asylum, RE: "AMPLIFIER DESIGNS FOR REDUCED IMD" (0.00)
Posted by PakProtector on 2021-11-21, 19:00:45 (23.125.73.217)
I don't think you even came close to examining the question I posed. I did not bring gNFB into the discussion for one. cheers, Douglas .......
167: Tube DIY Asylum, RE: "AMPLIFIER DESIGNS FOR REDUCED IMD" (0.00)
Posted by PakProtector on 2021-11-21, 17:31:26 (23.125.73.217)
OK, so if the FB means turns the pentode's plate curves into quite good looking triodes, what is the diff between amp response with a set of pentodes making them, or triodes that attempt to make such .......
168: Tube DIY Asylum, RE: "AMPLIFIER DESIGNS FOR REDUCED IMD" (0.00)
Posted by PakProtector on 2021-11-21, 17:29:41 (23.125.73.217)
"Any 'honest amplifier' has at least 40 dB of intermodulation free dynamic range when producing 70-80 dB SPL in the listening room." Wow...that is a few tens of mW output. Given I have substantially m .......
169: Tube DIY Asylum, RE: "AMPLIFIER DESIGNS FOR REDUCED IMD" (0.00)
Posted by PakProtector on 2021-11-21, 05:22:34 (23.125.73.217)
So TK, if you'd be so kind, 'why is IMD so bad'? Second, 'what exactly needs to happen with NFB to reduce it'? And no, I am not yankin' yer chain. I see no reason to doubt the many, thorough analysis .......
170: Tube DIY Asylum, 'common in PP amplifiers'? (0.00)
Posted by PakProtector on 2021-11-19, 18:52:16 (23.125.73.217)
Not at my house...LOL cheers, Douglas .......
171: Tube DIY Asylum, RE: amp build (0.00)
Posted by PakProtector on 2021-11-17, 04:30:02 (50.4.127.98)
Use of the current reg as a plate load is going to do away with the FB. It is what I suggest for the 12BH7 stage in a McIntosh to rid the circuit of positive FB w/o ruining the bootstrap-added voltage .......
172: Tube DIY Asylum, pushing it a bit, aren't we? (0.00)
Posted by PakProtector on 2021-11-08, 01:28:23 (23.125.73.217)
fabricated from aluminum bar stock by DT667 The pics don't show enough room for 'bar stock'. Unless your defining it as anything over an eighth of an inch thick (that is usually called strapping). Wh .......
173: Tube DIY Asylum, RE: :) extra holes (0.00)
Posted by PakProtector on 2021-11-05, 16:54:49 (23.125.73.217)
I don't think he built it. cheers, Douglas .......
174: Tube DIY Asylum, RE: :) extra holes (0.00)
Posted by PakProtector on 2021-11-04, 15:21:36 (23.125.73.217)
Don't look so surprised; especially considering he worships mrs. hundreds of amps 2A3. Fortunately writing such things is an skill, and he is sharpening his. Even if he was perfect; he'd still be just .......
175: Tube DIY Asylum, RE: batteries, anyone? (0.00)
Posted by PakProtector on 2021-11-03, 01:29:22 (23.125.73.217)
NMC is not the risk you make it out to be either. cheers, Douglas .......
176: Tube DIY Asylum, RE: batteries, anyone? (0.00)
Posted by PakProtector on 2021-11-02, 14:43:51 (23.125.73.217)
"SOC measurements aren't reliable if the battery isn't new/in excellent condition" That is also a mistaken assumption. Dude, do please get your paws on this sort of thing on a regular basis... :) Doug .......
177: Tube DIY Asylum, RE: batteries, anyone? (0.00)
Posted by PakProtector on 2021-10-31, 09:03:16 (23.125.73.217)
You can make a much better filter than a transformer core to filter out the switcher if you just stay DC. Besides, the so called 'pure sine wave' inverters are not even approaching quiet. There are a .......
178: Tube DIY Asylum, RE: batteries, anyone? (0.00)
Posted by PakProtector on 2021-10-31, 04:11:23 (23.125.73.217)
" Rechargeables--no one knows how much energy is in them" That is not the case. Even the near flat LiFePo4 discharge profile can have its SoC measured. NMC is waaay easier of course. If you're foolis .......
179: Tube DIY Asylum, RE: If I wired my amps with this stuff... (0.00)
Posted by PakProtector on 2021-10-30, 17:49:54 (23.125.73.217)
I may have to put in a few parallel runs for the cruise control signal...just to improve the speed holding precision. cheers, Douglas .......
180: Tube DIY Asylum, RE: If I wired my amps with this stuff... (0.00)
Posted by PakProtector on 2021-10-30, 03:59:08 (23.125.73.217)
I have some NOS RCA Litz... :) The 20 and 18 ga stuff looks like it was made yesterday. Unfortunately no RCA solder to go with it. I have some wiring to do in my TDI manual swap, and I think I better .......
181: Tube DIY Asylum, RE: If I wired my amps with this stuff... (0.00)
Posted by PakProtector on 2021-10-26, 03:03:26 (50.4.127.98)
I have used some heavy build, solderable( as in burn-it-off )insulated magnet wire. It looks scary... :) works quite nicely though. I even made 3.2 parallel runs with the stuff. cheers, Douglas ::: T .......
182: Tubes Asylum, RE: "Don't tell anybody" (0.00)
Posted by PakProtector on 2021-10-25, 16:37:56 (23.125.73.217)
I had a running Cit.ii and a pair of W6m carcasses...I kept the Heathkits and sold the restored Cit.ii. Too much money got waved under my nose. Cheers, Douglas .......
183: Tube DIY Asylum, If I wired my amps with this stuff... (0.00)
Posted by PakProtector on 2021-10-24, 18:02:44 (23.125.73.217)
as in the AL wire used to make voice coils, or the stuff that basically gets sold by the pound to wind the transformers...man how the zealots would squeal... :) But I don't so all is well...LOL-ing ch .......
184: Tube DIY Asylum, RE: sigmund fraud appears ... (0.00)
Posted by PakProtector on 2021-10-24, 16:02:10 (23.125.73.217)
There is a difference between observation, and hurling brickbats. Thanks to the prolific sets of claims by denise and his hangers-on, there is adequate sets of topics to observe and comment upon. 'hu .......
185: Tube DIY Asylum, and this completely ignores the fact that some use a glowing anode to getter themselves (0.00)
Posted by PakProtector on 2021-10-24, 14:27:51 (23.125.73.217)
but it for sure is not your magical, 100's of amps, 2A3. cheers, Douglas .......
186: Tube DIY Asylum, RE: Are you on dogfood? ... nope (0.00)
Posted by PakProtector on 2021-10-22, 10:28:08 (50.4.127.98)
And when did denise register? was that before or after I built the 4th set of amplifiers I discussed on here? Speaking of building, where is your stuff? cheers, Douglas .......
187: Tube DIY Asylum, Are you on dogfood? (0.00)
Posted by PakProtector on 2021-10-22, 01:35:50 (23.125.73.217)
Your ability to get things wrong *ALMOST surprises me. You have been getting them wrong in what would be spectacular if they were not part of a long string. Go double the idle current of your driver .......
188: Tube DIY Asylum, RE: Obvious forgeries, no 12AX7 in sight!!!!! (nt) (0.00)
Posted by PakProtector on 2021-10-21, 17:46:24 (23.125.73.217)
You, and your effects box enterprise are mistaken and I suspect I should include your 'panel' and all your hangers-on. Thanks for sharing your opinions though. cheers, Douglas .......
189: Tube DIY Asylum, RE: Obvious forgeries, no 12AX7 in sight!!!!! (nt) (0.00)
Posted by PakProtector on 2021-10-21, 04:16:39 (50.4.127.98)
But he makes up for that with a very low current operating point. At that point the plate curves are nearly horizontal. Pentode-level plate resistance and yooooge triode loading. That is the picture i .......
190: Tube DIY Asylum, Oh my... (0.00)
Posted by PakProtector on 2021-10-20, 16:30:36 (23.125.73.217)
Denise marginalizes himself. He does a fine job with your ever-so-skilled help. Looking forward to your next uninformed, ignorance-displaying attempt at insulting me...LMAO cheers, Douglas ::: TOPIC:: .......
191: Tube DIY Asylum, but of course... (0.00)
Posted by PakProtector on 2021-10-12, 18:02:01 (23.125.73.217)
One of the classic effects-box amplifier tricks. I like a heavily loaded pentode as input for a guitar pickup. The low capacitance input is not without value... :) and the low plate load enables more .......
192: Tube DIY Asylum, RE: An unrelated question, (0.00)
Posted by PakProtector on 2021-09-26, 12:23:55 (23.125.73.217)
Don't go including yourself. The SEMLP has not as yet gotten your application for observer-level membership yet. cheers, Douglas .......
193: Tube DIY Asylum, You are wrong about a lot... (0.00)
Posted by PakProtector on 2021-09-26, 04:29:38 (23.125.73.217)
But that surprises nobody. Even your accusations are made up. Now if you'd apply some of that imagination to your audio system design, It could be you might come up with something earth shattering...p .......
194: Tube DIY Asylum, RE: An unrelated question, (0.00)
Posted by PakProtector on 2021-09-25, 16:52:39 (23.125.73.217)
you said I was after too many stages. Gong to stay all TT DHT. And no magnetic amplification. And these shall work open loop; they are quite linear...and I don't care about output Z for this use. che .......
195: Tube DIY Asylum, Wow... (0.00)
Posted by PakProtector on 2021-09-25, 03:58:45 (23.125.73.217)
Your willingness to make assumptions that turn out to be wrong keeps popping up. Not that your bull-cookie logic is correct, but this is going to be two stage. If you still say this is not enough gain .......
196: Tube DIY Asylum, RE: red plates ... bob and weave ... (0.00)
Posted by PakProtector on 2021-09-24, 15:40:01 (23.125.73.217)
It is all about the delta V caused by the load R and the delta-i through it. At lower current there is a larger voltage to swing across between idle B+ and where the load line hits 0V. keep in mind th .......
197: Tube DIY Asylum, RE: An unrelated question, (0.00)
Posted by PakProtector on 2021-09-24, 03:43:51 (50.4.127.98)
I am glad to see that even somebody who has laid out the money for one of these has decided that there is something better out there, and is kicking it to the curb at a substantial discount. Says all .......
198: Tube DIY Asylum, RE: An unrelated question, (0.00)
Posted by PakProtector on 2021-09-23, 13:06:55 (23.125.73.217)
what a shock. after all dead-toob and DF wrote about them? Really? cheers, Douglas .......
199: Tube DIY Asylum, sounds like a nice wet bag... (0.00)
Posted by PakProtector on 2021-09-23, 07:25:41 (50.4.127.98)
and you have no idea what 'protected' means... cheers, Douglas .......
200: Tube DIY Asylum, RE: and a return to a previous question... :) (0.00)
Posted by PakProtector on 2021-09-23, 06:55:10 (50.4.127.98)
I think that we'd be safe with the paper bag you can't design your way out of. cheers, Douglas .......
201: Tube DIY Asylum, RE: Some E-Linear history (0.00)
Posted by PakProtector on 2021-09-23, 06:11:52 (50.4.127.98)
You are waaay to funny. Thanks for the note. cheers, Douglas .......
202: Tube DIY Asylum, RE: invoke the legal team ... (0.00)
Posted by PakProtector on 2021-09-23, 04:20:28 (50.4.127.98)
You are no doubt on to something there, and I thank you for the reminder. cheers, Douglas .......
203: Tube DIY Asylum, and a return to a previous question... :) (0.00)
Posted by PakProtector on 2021-09-22, 17:17:09 (23.125.73.217)
How many folk have built something that is YOURS? cheers, Douglas .......
204: Tube DIY Asylum, RE: invoke the legal team ... (0.00)
Posted by PakProtector on 2021-09-22, 17:12:40 (23.125.73.217)
He clearly can't be bothered to read the whole thing. Steps to realize how wrong he is: read the whole thing, esp the part where Pete attributes the naming...and then go ask that principal as to what .......
205: Tube DIY Asylum, RE: Some E-Linear history (0.00)
Posted by PakProtector on 2021-09-22, 17:10:06 (23.125.73.217)
One more time, go ask Pete... :D then report back. Do it...the critical bit being reporting back how his story differs from the BS you have been claiming... :) cheers, Douglas .......
206: Tube DIY Asylum, and since you invoke Pete... (0.00)
Posted by PakProtector on 2021-09-22, 13:28:08 (23.125.73.217)
ask him why it is called E-Linear... cheers, Douglas .......
207: Tube DIY Asylum, your 'more BS' is right on the money (0.00)
Posted by PakProtector on 2021-09-22, 13:24:44 (23.125.73.217)
and again your ignorance comes right through. Thanks DT for making it clear. You are just not worth the trouble required to rub your nose in just how badly you have it wrong. cheers, Douglas ::: TOPIC .......
208: Tube DIY Asylum, RE: red plates ... go ahead explain it (0.00)
Posted by PakProtector on 2021-09-22, 06:26:39 (50.4.127.98)
Your ignorance is showing again. I can't help you because you don't want me to. It is that simple. It has nothing to do with the circuit. The tubes are not over-biased either... :) cheers, Douglas :: .......
209: Tube DIY Asylum, RE: red plates ... bob and weave ... (0.00)
Posted by PakProtector on 2021-09-22, 04:02:24 (50.4.127.98)
The plates are not red. Not sure why you keep going after this...maybe you don't understand colours or something simple like that. cheers, Douglas .......
210: Tube DIY Asylum, RE: red plates ... 1 watt (0.00)
Posted by PakProtector on 2021-09-21, 16:40:08 (23.125.73.217)
Nice dodge there dead-toob. Keep right on going, at some point you may come upon something you can top somebody at. Also, just to be clear, I have no red-plating tubes. None, zero. Is that clear enoug .......
211: Tube DIY Asylum, RE: red plates ... (0.00)
Posted by PakProtector on 2021-09-21, 16:37:50 (23.125.73.217)
Quoted: When the incoming signal sees different bias on supposedly "balanced" (current-balanced only), tubes, guess what happens to your signal when it encounters unequal grid bias on different tubes? .......
212: Tube DIY Asylum, RE: red plates ... (0.00)
Posted by PakProtector on 2021-09-21, 11:20:17 (50.4.127.98)
well...once again you prove your ignorance beyond question. As for 2kV, another area you insist on displaying your substantial ignorance. As far as transducer efficiency, I don't think I exceed your .......
213: Tube DIY Asylum, RE: not worthy ... (0.00)
Posted by PakProtector on 2021-09-21, 08:22:03 (50.4.127.98)
What a fine salesman you are denis. I am at a loss to express my admiration for such a skill. cheers, Douglas .......
214: Tube DIY Asylum, RE: red plates ... (0.00)
Posted by PakProtector on 2021-09-21, 07:03:51 (50.4.127.98)
I go well beyond red there DT... :) If you knew anything about it, you'd say I was being too conservative and should run them hotter. cheers, Douglas .......
215: Tube DIY Asylum, RE: It's a No-Go (0.00)
Posted by PakProtector on 2021-09-21, 02:52:51 (50.4.127.98)
Try simple...hang a loaded source follower from a voltage divider. Mind the heat sinking, because the die is not saturated and localized hot spots make for hotter local hot spots. cheers, Douglas ::: .......
216: Tube DIY Asylum, RE: Screen Regulation with VR tubes? (0.00)
Posted by PakProtector on 2021-09-20, 08:23:46 (50.4.127.98)
I used a 0A3 to set up the g2 for a 6AV5 linestage. 50 mA idle, and a 1k plate load worked quite nicely. For PP power tubes you might wish to confirm that the load is within their capability. My solut .......
217: Tube DIY Asylum, RE: not worthy ... (0.00)
Posted by PakProtector on 2021-09-20, 08:19:59 (50.4.127.98)
Maybe if he adds a 4th 'blah'? On a serious note, it is all just effects box building. Interesting at first, and useful at shows where something technicolour is desired. Living with such things is alw .......
218: Tube DIY Asylum, RE: not worthy ... (0.00)
Posted by PakProtector on 2021-09-20, 03:26:10 (50.4.127.98)
I have no idea what BS goes on at trade shows to lead you to believe they matter. One, I sure don't live at a trade show. Two, I have been at this long enough to know that a 3W amp is going to suck mo .......
219: Tube DIY Asylum, errr...... (0.00)
Posted by PakProtector on 2021-09-20, 03:18:58 (50.4.127.98)
Not using cathode bias resistor bypass caps. Fixed bias. Decent filter design, and low output Z from the pots and where possible, grid chokes. (so far it has been extremely possible) The rest ought t .......
220: Tube DIY Asylum, I just love it... (0.00)
Posted by PakProtector on 2021-09-18, 15:45:12 (23.125.73.217)
and we are clearly not worthy. Or we could properly conclude that you are on dog food, and being the best salesman you know how to be. I am going to consistently bet on the latter. cheers, Douglas :: .......
221: Tube DIY Asylum, RE: LMAO.... (0.00)
Posted by PakProtector on 2021-09-14, 14:28:26 (23.125.73.217)
nah...not bitchin. Noting inconsistency maybe... :) largely for the humor...no SS in the 'signal path' and then bitches about a problem caused by SS in the signal path. Gotta love that irony...and the .......
222: Tube DIY Asylum, RE: just cross out 'machine gun'... (0.00)
Posted by PakProtector on 2021-09-07, 17:14:34 (23.125.73.217)
It only looks small on log paper... :) cheers, Douglas .......
223: Tube DIY Asylum, just cross out 'machine gun'... (0.00)
Posted by PakProtector on 2021-09-07, 03:40:49 (50.4.127.98)
and write in 'pizza oven' cheers, Douglas .......
224: Tube DIY Asylum, RE: exceptions (0.00)
Posted by PakProtector on 2021-09-03, 18:04:11 (23.125.73.217)
Dood...mail order and install it yourself. cheers, Douglas .......
225: Tube DIY Asylum, RE: sheep ... (0.00)
Posted by PakProtector on 2021-09-03, 09:28:11 (50.4.127.98)
Yah, and if it doesn't we shall continue...assuming a next mutation does not do you in. Here is your assignment just in case I am mistaken(two parts): Catalog and chart the progression of the propaga .......
226: Tube DIY Asylum, Wow... (0.00)
Posted by PakProtector on 2021-09-03, 07:57:16 (50.4.127.98)
and you call other folks, sheep? Lemme get you a mirror.... :) cheers, Douglas .......
227: Tube DIY Asylum, He's vaccinated alright... (0.00)
Posted by PakProtector on 2021-09-03, 07:29:42 (50.4.127.98)
I think they tested the 'common sense' one on him...it worked as we see on a daily basis. They also tried out the new 'cult recognition' one. His attempted membership in the MLP shows that one worked .......
228: Tube DIY Asylum, RE: 12BH7 vs 6SN7GTB (0.00)
Posted by PakProtector on 2021-09-03, 07:23:09 (50.4.127.98)
I just love the claim that it is only how it sounds that matters. I don't quite think you have any idea how good a sim can be these days. The other half of that is, I also don't think you have any ide .......
229: Tube DIY Asylum, RE: 12BH7 vs 6SN7GTB (0.00)
Posted by PakProtector on 2021-09-03, 07:11:50 (50.4.127.98)
Not entirely just a left vs right of operating point, though at any given instant it effectively is. The V(out)=f(V_in). The f(v_in) can have various terms other than a constant times V_in... I'd sugg .......
230: Tube DIY Asylum, RE: 12BH7 vs 6SN7GTB (0.00)
Posted by PakProtector on 2021-09-02, 16:42:50 (23.125.73.217)
One of these loooowMooo amps can not do a microsecond pulse at their OPT secondaries. Getting a 2A3 to do that is just a matter of grid drive with a resistive load. That grid drive is *NOT going to ha .......
231: Tube DIY Asylum, RE: 12BH7 vs 6SN7GTB (0.00)
Posted by PakProtector on 2021-09-02, 07:29:00 (50.4.127.98)
What ever denis...- You can go right ahead claiming all sorts of things. High currents? you have got some idea of what is happening, but your conclusions are in the weeds based likely on some Marketin .......
232: Tube DIY Asylum, what on earth are you going on about now? (0.00)
Posted by PakProtector on 2021-09-01, 17:06:27 (23.125.73.217)
Damage? from the Trump Vaccine? I doubt it. cheers, Douglas .......
233: Tube DIY Asylum, RE: ??? (0.00)
Posted by PakProtector on 2021-09-01, 14:51:44 (23.125.73.217)
Oh no, rage likes me better. not you. I have proof. cheers, Douglas .......
234: Tube DIY Asylum, RE: 12BH7 vs 6SN7GTB (0.00)
Posted by PakProtector on 2021-09-01, 08:28:05 (50.4.127.98)
'reproduce music accurately' is an easy measurement. You start wid the big stuff...distortion spectra...and overall fractional content. IFF it makes that gross, black/white, yes/no and quantity then .......
235: Tube DIY Asylum, RE: trust ... (0.00)
Posted by PakProtector on 2021-09-01, 08:22:37 (50.4.127.98)
Oh no...Kool-Aide is good for ya. Drink all they will serve you DT. cheers, Douglas .......
236: Tube DIY Asylum, RE: 12BH7 vs 6SN7GTB (0.00)
Posted by PakProtector on 2021-08-31, 16:24:27 (23.125.73.217)
So...your wiring, both kind, gage, routing, how much do you think it matters? I bet it could possibly be measured( due to routing ), but if you suggest it is a lot, the design needs help. Of course, y .......
237: Tube DIY Asylum, RE: picture of Dennis' amp (0.00)
Posted by PakProtector on 2021-08-31, 15:26:09 (23.125.73.217)
last I checked, heart failure/blood clots were also attributed to covid. I am unsurprised that the vaccine response can trigger that too. For those who get that triggered, I'd bet heavily that covid i .......
238: Tube DIY Asylum, RE: Oh my... (0.00)
Posted by PakProtector on 2021-08-31, 09:27:00 (50.4.127.98)
Don't worry about the pile on, while appearing light on professionalism, rest assured it is not piling on to any at all. It could be that the rules could prohibit showing how and why a post is wrong, .......
239: Tube DIY Asylum, RE: picture of Dennis' amp (0.00)
Posted by PakProtector on 2021-08-31, 03:28:00 (50.4.127.98)
Turns out the chem trails are actually full of covid vaccine. Of more particular interest, the mRNA in them also lets you spot SE, effects box amplifiers from 2.718282 miles away and let you see that .......
240: Tube DIY Asylum, exceptions (0.00)
Posted by PakProtector on 2021-08-30, 08:26:32 (50.4.127.98)
My pop made the acquaintance of a home building carpenter. This man worked w/o prints, and took great pride in getting to the point where he put down his saw and picked up his hammer to start assembly .......
241: Tube DIY Asylum, RE: picture of Dennis' amp (0.00)
Posted by PakProtector on 2021-08-30, 03:15:50 (50.4.127.98)
Unfortunately, very little of that Consumer Protection law ever gets enforced anymore. Truth be told, I'd rather they went after a large group of what I'd call, 'bigger fish'. The way denis runs his a .......
242: Tube DIY Asylum, RE: You've Obviously Misunderstood (0.00)
Posted by PakProtector on 2021-08-29, 08:26:19 (23.125.73.217)
Clearly misunderstood...it is a good thing the PS is not in the signal path. cheers, Douglas .......
243: Tube DIY Asylum, RE: picture of Dennis' amp (0.00)
Posted by PakProtector on 2021-08-27, 15:16:23 (23.125.73.217)
Oh...right, I forgot about that 'unstressed components' bit. Clearly makes all the difference. I thought it was your 3D design. Or maybe something else is more critical. What ever it is, it is yours .......
244: Tube DIY Asylum, RE: picture of Dennis' amp (0.00)
Posted by PakProtector on 2021-08-27, 10:22:14 (50.4.127.98)
I thought the operating point was for the sound, not for longevity. The latter being a happy side effect as far as you were concerned. cheers, Douglas .......
245: Tube DIY Asylum, RE: LMAO.... (0.00)
Posted by PakProtector on 2021-08-27, 07:59:00 (50.4.127.98)
If you had read much of TK's postings, you would note a distinct aversion to SS items. cheers, Douglas .......
246: Tube DIY Asylum, LMAO.... (0.00)
Posted by PakProtector on 2021-08-27, 03:14:17 (50.4.127.98)
Wow...SS rectification. One problem after another. Complete with another application of SS to cure the original issue. This is about the most entertainingly ironic post I have seen in a while. cheers, .......
247: Tube DIY Asylum, RE: picture of Dennis' amp (0.00)
Posted by PakProtector on 2021-08-27, 01:17:32 (23.125.73.217)
Dude, that amp would get thrown outta my system faster than I could manage a polite, 'thanks for bring it over to listen to'. Tubes with plates getting pushed so hard they glow orange would return to .......
248: Tube DIY Asylum, RE: marketing ... why DF wins again (0.00)
Posted by PakProtector on 2021-08-27, 01:12:42 (23.125.73.217)
'DF is simply a better and more experienced audio professional who understand the psychology of the business better than any of his critics.' That is what I said. English must be a second lanwidge to .......
249: Tube DIY Asylum, RE: "He has conflated slew rate with overall magnitude." (0.00)
Posted by PakProtector on 2021-08-26, 11:19:10 (50.4.127.98)
One of the entertaining tasks I take on from time to time is short-circuit max current delivery from batteries, and how they tolerate said abuse. I have seen multi-thousands of amps out of Iron phosph .......
250: Tube DIY Asylum, RE: "He has conflated slew rate with overall magnitude." (0.00)
Posted by PakProtector on 2021-08-26, 10:50:36 (50.4.127.98)
There is *NOTHING on the primary side of the OPT that allows that. Even the DCR of the primary puts a stake through that monster's heart... LOL cheers, Douglas .......
251: Tube DIY Asylum, RE: You are wrong (0.00)
Posted by PakProtector on 2021-08-26, 09:49:04 (50.4.127.98)
It is more basic than that; the amp is not capable of doing what he says. He has conflated slew rate with overall magnitude. Given his stated bandwidth( easy to predict given the tubes he chooses) it .......
252: Tube DIY Asylum, RE: DF builds chip amps (0.00)
Posted by PakProtector on 2021-08-26, 09:46:25 (50.4.127.98)
DT, denise sells tube amps to folks who don't know enough to call up his Marketing( I assume, since I'd not consider buying such misrepresented crap from anybody, no matter what it was). It is careful .......
253: Tubes Asylum, RE: Sounds like fun (nt) (0.00)
Posted by PakProtector on 2021-08-26, 08:47:06 (50.4.127.98)
can't say that I did not occasionally get jealous of the motorized folks...LOL Douglas .......
254: Tube DIY Asylum, Ok then... (0.00)
Posted by PakProtector on 2021-08-25, 16:28:44 (23.125.73.217)
So denise can run a 2A3 so that it draws a fantastic amount of current through the OPT's primary. So then either it is going up in smoke as wasted heat...or it is coming out the secondary. Given the s .......
255: Tube DIY Asylum, Oh my... (0.00)
Posted by PakProtector on 2021-08-25, 15:40:41 (23.125.73.217)
You throw Tesla's name around, and yet you have absolutely no idea what he was up to or how he did it. I'll give you a hint; all that he was up to is thoroughly explained by the first two volumes of .......
256: Tubes Asylum, RE: there is a code (0.00)
Posted by PakProtector on 2021-08-25, 07:21:04 (50.4.127.98)
GA2 is the type, and B0A3 is location and date. B is Blackburn Mullard plant IIRC, but check all this with Ivan's code linque...- :) Douglas .......
257: Tube DIY Asylum, HA! (0.00)
Posted by PakProtector on 2021-08-24, 15:05:02 (23.125.73.217)
The thing is the drawing and the drawing is the thing. That actually applies to transistors these days( and has for some time now)...LOL cheers, Douglas 'But these are the *BLUE Drawings'! Purple the .......
258: Tube DIY Asylum, Dear Sir.... (0.00)
Posted by PakProtector on 2021-08-24, 15:02:07 (23.125.73.217)
You insult the term, 'a blah blah blah blah answer' by comparing it to something Denis says. A single 'blah' contains infinitely more information than a years worth of 'writings' by denis. You know wh .......
259: Tubes Asylum, RE: Where to find lists of 4v and 5v small signal tubes? (0.00)
Posted by PakProtector on 2021-08-23, 15:57:33 (23.125.73.217)
I am no expert in this, but got told that the tdsl has a search function...it may be limited to stuff wid the same pin-out, but I suspect it will cover the various heater voltages. Paul/Kegger was th .......
260: Tube DIY Asylum, RE: 6V6 Maximum Anode Voltage? (0.00)
Posted by PakProtector on 2021-08-23, 10:00:01 (23.125.73.217)
Seems arcing could be an issue as the tube tries to cut off a tX-coupled load. No matter what the DC, the time spent across a low-current peak of voltage is effectively 'forever' as far as the electro .......
261: High Efficiency Speaker Asylum, Yeah...now make it 14' long and load some 12's with it (0.00)
Posted by PakProtector on 2021-08-21, 18:12:40 (23.125.73.217)
Two side by side. Maybe adjust the math on the notch and only take it down half way. 12" Boomer Co. cement casting tube... :) cheers, Douglas .......
262: Tube DIY Asylum, RE: EF86 - 300B XLS "Hybrid" project (0.00)
Posted by PakProtector on 2021-08-18, 15:34:07 (23.125.73.217)
That is what I wanted to ask...musta been low on coffee. It is ultimately the connection to the power tube that likes direct connection to a low impedance drive... :) cheers, Douglas .......
263: Tube DIY Asylum, RE: EF86 - 300B XLS "Hybrid" project (0.00)
Posted by PakProtector on 2021-08-18, 01:31:09 (23.125.73.217)
Hey did you cap couple a source follower? cheers, Douglas .......
264: Tubes Asylum, RE: I'd say that is a great story (0.00)
Posted by PakProtector on 2021-08-17, 08:11:10 (50.4.127.98)
Wow...and I thought riding 100 miles in 7 hours was pretty sweet. It was in the summer...lots of fun in -7F with studded snow tires, riding trails and rivers. Best epic ride ever. cheers, Douglas ::: .......
265: Tube DIY Asylum, RE: Hmm, (0.00)
Posted by PakProtector on 2021-08-08, 17:02:00 (23.125.73.217)
The example of the sun is no, 'more out than in'. That is just energy release on a rather fantastic( compared to a lightbulb) scale...and yet given the finite fuel source, it is going to go through a .......
266: Tube DIY Asylum, RE: Over Unity = Perpetual Motion (0.00)
Posted by PakProtector on 2021-08-07, 17:22:35 (23.125.73.217)
right...more out than in is possible. (checks grounding of tin-foil hat, and turns up electromagnet coil wrapped around body to keep the microchips injected into the vaccine believers from effecting M .......
267: Tube DIY Asylum, RE: preaching gospels to geese ... (0.00)
Posted by PakProtector on 2021-08-03, 10:07:54 (50.4.127.98)
In applications much less sensitive to noise, such as a CAN-based control system, such measures on the cable shields always result in too much noise. A much more robust solution is required. cheers, D .......
268: Tube DIY Asylum, RE: Hmm, (0.00)
Posted by PakProtector on 2021-08-03, 08:46:07 (50.4.127.98)
This one would not tax the intelligence of my dog( she is smart for a dog though ): 'no physical laws are violated' and 'more energy out than input' are mutually contradictory statements. Have yoursel .......
269: Tube DIY Asylum, RE: Over Unity = Perpetual Motion (0.00)
Posted by PakProtector on 2021-08-02, 08:02:39 (50.4.127.98)
Dude, getting free energy is a long standing, and well respected( amongst con-men ) demonstration. Anybody who actually could do it would be lotto-rich in about 2 hours time... cheers, Douglas ::: TOP .......
270: Tube DIY Asylum, RE: Over Unity = Perpetual Motion (0.00)
Posted by PakProtector on 2021-07-30, 06:41:34 (50.4.127.98)
Oh, yeah...there has been a long line of folks good enough to fool somebody into believing it. It is *WAY too profitable to ignore if it was real... cheers, Douglas .......
271: Tube DIY Asylum, RE: Hmm, (0.00)
Posted by PakProtector on 2021-07-30, 01:27:30 (23.125.73.217)
That is not a very descriptive answer. Have to say it sounds impossible. cheers, Douglas .......
272: Tube DIY Asylum, RE: Hmm, (0.00)
Posted by PakProtector on 2021-07-29, 14:12:46 (23.125.73.217)
'Over unity power'? what is this? cheers, Douglas .......
273: Tube DIY Asylum, RE: You are mis-quoting ... perhaps (0.00)
Posted by PakProtector on 2021-07-28, 15:17:30 (23.125.73.217)
They are only a moving target for blind folks. Everybody else sees quite plainly what the mop crew is up to. cheers, Douglas .......
274: Tube DIY Asylum, HA! (0.00)
Posted by PakProtector on 2021-07-28, 09:21:54 (50.4.127.98)
We just did. We even used a method stolen by your mop club. cheers, Douglas .......
275: Tube DIY Asylum, You are mis-quoting (0.00)
Posted by PakProtector on 2021-07-28, 06:10:06 (50.4.127.98)
It was 3.625 parallel runs that he suggested. It was likely 11 ga too, but who's counting? cheers, Douglas .......
276: Tube DIY Asylum, RE: GFY there TK (0.00)
Posted by PakProtector on 2021-07-28, 04:22:05 (50.4.127.98)
"You took that last line WAY too seriously. Maybe...it has happened. I think it is largely a means to get rid of 'other than signal' voltage present that is due to grid current. This grid current is n .......
277: Tube DIY Asylum, RE: Thoughts on Input resistor? (0.00)
Posted by PakProtector on 2021-07-28, 01:15:02 (23.125.73.217)
Alright, now what exactly did you take me to mean when I invoked the term 'contact bias'. Douglas .......
278: Tube DIY Asylum, RE: Thoughts on Input resistor? (0.00)
Posted by PakProtector on 2021-07-27, 16:25:29 (23.125.73.217)
Yes, the relatively broad area in a DH tube where grid current starts to get underway is a decent reason to use a grid choke. The use of large resistors for contact bias, IMO proves that a wee bit of .......
279: Tube DIY Asylum, RE: enjoy mid-fi ... (0.00)
Posted by PakProtector on 2021-07-27, 05:11:16 (50.4.127.98)
good luck wid that... :) You will figure it out eventually. I have an 'I told you so' all packaged and waiting. cheers, Douglas .......
280: Tube DIY Asylum, RE: Thoughts on Input resistor? (0.00)
Posted by PakProtector on 2021-07-27, 02:40:59 (50.4.127.98)
Alright, do let me in on this DHT reasoning; I don't have any experience at all with 'em. cheers, Douglas .......
281: Tube DIY Asylum, RE: Thoughts on Input resistor? (0.00)
Posted by PakProtector on 2021-07-26, 17:23:08 (23.125.73.217)
Unless you are driving off the mu output, then what ever you load it with will be your delivered load line, and IME, no...less is more in the case of grid resistors. The 'within its ability to drive i .......
282: Tube DIY Asylum, RE: enjoy mid-fi ... (0.00)
Posted by PakProtector on 2021-07-26, 16:59:01 (23.125.73.217)
Like I said, if there was any value to it, I would show you just how mistaken you are. It is a worthless exercise, and the worst I could do is to let you keep your ideas. cheers, Douglas .......
283: Tubes Asylum, RE: Good one (0.00)
Posted by PakProtector on 2021-07-26, 15:19:23 (23.125.73.217)
Given how this was going, I did wonder how long it would take for that to appear. cheers, Douglas .......
284: Tube DIY Asylum, GFY there TK (0.00)
Posted by PakProtector on 2021-07-26, 14:22:34 (23.125.73.217)
I do love your ability to dismiss without listening, or that you assume that you'd not hear anything. As far as calling me, 'Jeff', your parents are brothers. cheers, Douglas .......
285: Tube DIY Asylum, can't have that... :) (0.00)
Posted by PakProtector on 2021-07-26, 03:04:24 (50.4.127.98)
It was not my intention to see you waste any beer. Or cause a need to do laundry cleaning up said wasted beer. cheers, Douglas .......
286: Tube DIY Asylum, tell you what.... (0.00)
Posted by PakProtector on 2021-07-26, 02:57:56 (50.4.127.98)
With a handful of grid chokes in hand, try the experiment. Note I did not say it was due to the linearity of the grid resistance. What I said was lower is better, and so far grid chokes have been the .......
287: Vintage Asylum, RE: Anyone looking for a Marantz 8 amp (0.00)
Posted by PakProtector on 2021-07-24, 15:57:59 (23.125.73.217)
Nice looking amp. And close by too... :) cheers, Douglas .......
288: Tube DIY Asylum, RE: Thoughts on Input resistor? (0.00)
Posted by PakProtector on 2021-07-24, 05:47:30 (23.125.73.217)
I'd slightly disagree on the 'no benefit', not even going into the 'modern' part of it. Within the ability of the stage ahead of it being able to drive it, things like low value resistors and grid cho .......
289: Tubes Asylum, RE: Jim McShane is always my first choice for buying tubes (0.00)
Posted by PakProtector on 2021-07-23, 15:24:52 (23.125.73.217)
Even if you'd look twice as good as me, don't indulge them... :D cheers, Douglas .......
290: Tube DIY Asylum, RE: Thoughts on Input resistor? (0.00)
Posted by PakProtector on 2021-07-23, 14:57:59 (23.125.73.217)
I like the input resistance low. 47k is light enough I can let somebody else's linestage drive it. I find 5k slightly better... :) None of my linestages are short of drive. cheers, Douglas ::: TOPIC:: .......
291: Tube DIY Asylum, RE: Opinions sought re cascode driver stage for 300B (0.00)
Posted by PakProtector on 2021-07-23, 08:23:46 (50.4.127.98)
Err...talking about composite elements; as in a cascode...basically a 'build a pentode' out of two elements...yes? cheers, Douglas .......
292: Tube DIY Asylum, RE: Opinions sought re cascode driver stage for 300B (0.00)
Posted by PakProtector on 2021-07-22, 17:04:13 (23.125.73.217)
Couple things... :) You are building a pentode. One that can't swing plate voltage below its screen. A 5687 section will do just fine for the input, and to maximize available output, use a MOSFET on t .......
293: Tube DIY Asylum, RE: Film Capacitor Orientation Question (0.00)
Posted by PakProtector on 2021-07-21, 17:16:12 (23.125.73.217)
I think you might miss the basis of Fizbin. GO is a fine game... :) cheers, Douglas .......
294: Tube DIY Asylum, That ought to cover it. (0.00)
Posted by PakProtector on 2021-07-20, 16:16:59 (23.125.73.217)
If you have any doubts, continue...LOL cheers, Douglas .......
295: Tube DIY Asylum, No...I don't think that is it. (0.00)
Posted by PakProtector on 2021-07-19, 16:15:45 (23.125.73.217)
I do believe this is directed at the person behind the moniker. And just to recall one of your favourites; if it looks like a duck and quacks like a duck, it is a duck, or at least wants everybody to .......
296: Tube DIY Asylum, RE: Film Capacitor Orientation Question (0.00)
Posted by PakProtector on 2021-07-19, 07:14:35 (50.4.127.98)
Thanks! Explaining Featherston to dead tube 33-1/3 is going to be a wee more difficult... LOL Douglas .......
297: Tube DIY Asylum, RE: Film Capacitor Orientation Question (0.00)
Posted by PakProtector on 2021-07-19, 05:53:56 (50.4.127.98)
Only accomplished, tournament grade Fizbin players know all the rules to follow about capacitors. cheers, Douglas .......
298: Tube DIY Asylum, RE: Film Capacitor Orientation Question (0.00)
Posted by PakProtector on 2021-07-18, 16:41:22 (23.125.73.217)
There are some real Nazi's still living. They are not worth much to that basic movement thanks to their actual involvement in The Real Thing. The current crop is after the same basic thing, though the .......
299: SET Asylum, RE: Here you go ........ (0.00)
Posted by PakProtector on 2021-07-17, 03:31:31 (23.125.73.217)
Neat primary arrangement; offers the ability to run different g2 ratio if applied to a pentode final... :) cheers, Douglas .......
300: Tube DIY Asylum, RE: Film Capacitor Orientation Question (0.00)
Posted by PakProtector on 2021-07-16, 15:58:35 (23.125.73.217)
I once read a website written by an idiot. I am sure my visit got classified the same way you classify all yours. cheers, Douglas .......
301: Tube DIY Asylum, RE: Film Capacitor Orientation Question (0.00)
Posted by PakProtector on 2021-07-15, 15:03:01 (23.125.73.217)
you are so damn funny... If there was any value in a win, I'd offer to clean your clock with an amp doing so many 'wrong' things you'd claim it could not even pass a signal. cheers, Douglas ::: TOPIC: .......
302: Tube DIY Asylum, RE: Heyboer Gone? (0.00)
Posted by PakProtector on 2021-07-10, 14:16:11 (23.125.73.217)
I highly doubt it. I talked to Alden a little while ago, and they were busy and saw no end in sight. cheers, Douglas .......
303: SET Asylum, RE: OT. When did people start confusing Copyrights with Patents? (0.00)
Posted by PakProtector on 2021-07-09, 14:40:35 (23.125.73.217)
And there is a lot of that going around. Threats to sue if something gets copied or examined, or god forbid documented. I recall seeing a lot it on some newsgroup or another regarding some sort of tra .......
304: Tube DIY Asylum, RE: Because tubes rule! (0.00)
Posted by PakProtector on 2021-06-26, 12:59:41 (23.125.73.217)
I thoroughly enjoyed getting a warranty replacement for a RS Lifetime-branded GE 6CA7. It was a Sovtek EL34, and I never used it...but the fun the young lady at RS went through to get it for me was pr .......
305: Tube DIY Asylum, the Math behind LC filter output voltage (0.00)
Posted by PakProtector on 2021-06-25, 15:14:00 (23.125.73.217)
For a rectified sine function, the Fourier series has an a_0 term. No sine function of any sort along with it. This is the DC component. Its magnitude is 4/Pi times the voltage input, which of course .......
306: Tube DIY Asylum, more historical contradictions to DT's thesis (0.00)
Posted by PakProtector on 2021-06-25, 08:46:45 (50.4.127.98)
The McIntosh 50W-1 came about in 1949. The MC30 got turned loose in 1954. cheers, Douglas .......
307: Tube DIY Asylum, no kidding... (0.00)
Posted by PakProtector on 2021-06-24, 15:50:21 (23.125.73.217)
or the distances between peaks are different, you have a wrong value in there somewhere. Yeah, like variable line frequency. Which I suspect is impossible to have PSUDii deliver. Nice strawman thoug .......
308: Tube DIY Asylum, RE: LC filters for B+ ... (0.00)
Posted by PakProtector on 2021-06-24, 15:40:51 (23.125.73.217)
Everything is choke input. There is some stray chokiness just because it is a wire, transiting the distance between diode and the cap. When did you ever see a salesman ever worry about the truth? Exam .......
309: Tube DIY Asylum, Get your damn accusations straight (0.00)
Posted by PakProtector on 2021-06-24, 15:36:34 (23.125.73.217)
I am not an EE. I am an Engineer. cheers, Douglas .......
310: Tube DIY Asylum, RE: admission ... ? (0.00)
Posted by PakProtector on 2021-06-24, 15:06:14 (23.125.73.217)
And why would it be 'better' to ask a person wid no track record of giving straight honest answers anything. In order to figure out what he is actually up to, just read it all...avoid barfing as possi .......
311: Tube DIY Asylum, RE: LTP VS Differential Amplifier (0.00)
Posted by PakProtector on 2021-06-19, 04:26:56 (23.125.73.217)
What in the hell is eqn 92 and 94?...and feel free to put up the corrected version. Douglas .......
312: Tube DIY Asylum, RE: another ... you tried to help (0.00)
Posted by PakProtector on 2021-06-18, 15:56:46 (23.125.73.217)
The only time wasted is in reading the stuff you write. It could be you are on to something with LC filters for B+. If I thought you'd be able to pay off a bet on a listening test/amp sampling sessio .......
313: Tube DIY Asylum, RE: LTP VS Differential Amplifier (0.00)
Posted by PakProtector on 2021-06-18, 10:10:22 (50.4.127.98)
With a grid grounded in a diff amp, that section is not presenting a gain of mu+1 as it would if the circuit could be treated as a grounded cathode and a grounded grid. The balance is dependent on the .......
314: Tube DIY Asylum, RE: PI Balance (0.00)
Posted by PakProtector on 2021-06-18, 06:02:41 (50.4.127.98)
For all the worry about balance, a lot of the stuff I have built of late runs a pentode LTP. Screen current is not going through the loads, but most certainly is passing through a cascode MOSFET curre .......
315: Tube DIY Asylum, RE: LTP VS Differential Amplifier (0.00)
Posted by PakProtector on 2021-06-18, 01:55:53 (23.125.73.217)
Couple of things, the grounded grid amplification factor of mu+1 leaves it requiring that side to have higher gain even with balanced resistors. That never happens. So the basic issue seems to be th .......
316: Tube DIY Asylum, RE: the section with the grid grounded *NEVER has more gain (0.00)
Posted by PakProtector on 2021-06-17, 15:00:43 (23.125.73.217)
So then, with a large Rk, where is this input going? cheers, Douglas .......
317: Tube DIY Asylum, RE: Current Change (0.00)
Posted by PakProtector on 2021-06-16, 17:56:37 (23.125.73.217)
Well, have fun with your PP adventures. cheers, Douglas .......
318: Tube DIY Asylum, RE: What I like about the Crowhurst analysis (0.00)
Posted by PakProtector on 2021-06-16, 16:17:46 (23.125.73.217)
I have built with cascaded LTP's too. They do a very fine job IME if the gain is needed. Since I like a medium-mu linestage, two-stage amps have done quite well. The latest are LTP's for balanced driv .......
319: Tube DIY Asylum, RE: What I like about the Crowhurst analysis (0.00)
Posted by PakProtector on 2021-06-16, 15:26:18 (23.125.73.217)
The grounded grid has more gain than a grounded cathode. And yet the section with the grid grounded *NEVER has more gain. cheers, Douglas .......
320: Tube DIY Asylum, RE: What I like about the Crowhurst analysis (0.00)
Posted by PakProtector on 2021-06-16, 14:42:00 (23.125.73.217)
If the tube with no signal on its grid actually has more gain, it would work to compensate for an imperfect tail load. The circuit works the other way... cheers, Douglas .......
321: Tube DIY Asylum, RE: LTP VS Differential Amplifier (0.00)
Posted by PakProtector on 2021-06-16, 07:20:24 (50.4.127.98)
So with one grid driven the balance is delivered by the magnitude of the cathode resistor( be it a resistor or a ccs). With two grids driven, the balance is STILL driven by Rk. The Rk still delivers b .......
322: Tube DIY Asylum, RE: That is where the rot creeps in (0.00)
Posted by PakProtector on 2021-06-16, 04:24:56 (50.4.127.98)
I thought I saw justification for different output presented with grounded grid to grounded cathode gain. Douglas .......
323: Tube DIY Asylum, RE: That is where the rot creeps in (0.00)
Posted by PakProtector on 2021-06-16, 03:39:59 (50.4.127.98)
The point I am trying to make is that this grounded cathode amp y'all insist on labeling it as is not a grounded cathode amp anymore, and can not be examined as such since it is tied up in the LTP cir .......
324: Tube DIY Asylum, RE: That is where the rot creeps in (0.00)
Posted by PakProtector on 2021-06-16, 03:36:15 (50.4.127.98)
Don't quite feel like coming up with the equations. I am quite happy with the conclusion that the usual input side can not be considered a grounded cathode amp. I suspect the proof of this will resemb .......
325: Tube DIY Asylum, RE: That is where the rot creeps in (0.00)
Posted by PakProtector on 2021-06-16, 01:49:52 (23.125.73.217)
So if there is signal on the grounded grid, it becomes a different circuit? Douglas .......
326: Tube DIY Asylum, RE: That is where the rot creeps in (0.00)
Posted by PakProtector on 2021-06-15, 17:32:04 (23.125.73.217)
I see plenty wrong with it. It comes down to there being no difference in reaction if the grids are driven balanced or if one side is fed no signal. The output is different in magnitude, as expected s .......
327: Tube DIY Asylum, That is where the rot creeps in (0.00)
Posted by PakProtector on 2021-06-15, 14:29:33 (23.125.73.217)
Either both are grounded grid, or neither are, or they act like something in the middle...but they are the same. cheers, Douglas .......
328: Tube DIY Asylum, RE: Crowhurst et al... (0.00)
Posted by PakProtector on 2021-06-15, 10:35:04 (50.4.127.98)
'f'-FIX-1, and *MY random number generator took about 7 tries to hit 5( .5 actually ). cheers, Douglas .......
329: Tube DIY Asylum, RE: Crowhurst et al... (0.00)
Posted by PakProtector on 2021-06-15, 08:22:43 (50.4.127.98)
How big shall we make this cap???? :) Douglas .......
330: Tube DIY Asylum, RE: Current Change (0.00)
Posted by PakProtector on 2021-06-15, 04:35:34 (50.4.127.98)
I am not going through the olde math. It is clearly poorly presented. The sum of the two sections current is a constant. At idle the two sections do not need equal currents. For the time being, treat .......
331: Tubes Asylum, RE: 6SL7 needed in a tube integrated amp (0.00)
Posted by PakProtector on 2021-06-14, 18:21:43 (23.125.73.217)
Where are NOS 6SL7's going for more than $50 each? Any particular kind? If y'all answer, 'everywhere' I think I shall convert some into additions to my Iron collection for the next amps. How 'bout 6SU .......
332: Tubes Asylum, RE: It may have gotten a bit warm (0.00)
Posted by PakProtector on 2021-06-14, 17:08:51 (23.125.73.217)
Saw a pic of an SVT equipped with 6550's. All of them pulled the glass onto the plate. two still had shiny getters. These were the small Sylvania 6550...so perhaps a concentrated hot spot was possible .......
333: Tube DIY Asylum, It is obvious they are not following conventional EE practices (0.00)
Posted by PakProtector on 2021-06-14, 15:05:39 (23.125.73.217)
Conventional EE practices lead to things that work( like reproducing a 20 cps note) without being tens of dB down from where they reproduce a 1kHz one. By his own admission, and yours, the amps suck-d .......
334: Tubes Asylum, RE: This means that the tube was used a I right? (0.00)
Posted by PakProtector on 2021-06-14, 10:16:47 (50.4.127.98)
I don't think use moves getter around like that. Now the dark spots opposite the round hole in a Mullard EL84 plate are quite something else. cheers, Douglas .......
335: Tube DIY Asylum, RE: Dave... (0.00)
Posted by PakProtector on 2021-06-14, 09:58:38 (50.4.127.98)
Actually it is a matter of covering everything that can possibly count. And then explaining it thoroughly without missing anything. Pretty simple...LOL Douglas .......
336: Tube DIY Asylum, HA! (0.00)
Posted by PakProtector on 2021-06-14, 09:53:37 (50.4.127.98)
I can read the 10Mxx spec sheets...LOL Don't mistake me for thinking that beast is a good CCS used singly. Your spice results about parallel what I discovered whilst running longer and longer resistor .......
337: Tube DIY Asylum, RE: Rosenblit Also Got This Wrong (0.00)
Posted by PakProtector on 2021-06-14, 08:01:06 (50.4.127.98)
Now you are adding specific words to what they wrote. Ones that while useful go a long way to forward the idea that these folks were brilliant writers about the subject. It is irrelevant how brilliant .......
338: Tube DIY Asylum, RE: Rosenblit Also Got This Wrong (0.00)
Posted by PakProtector on 2021-06-14, 07:26:38 (50.4.127.98)
That is what I am trying to get you to see; the one is no more a grounded grid deserving special treatment than the other. I asked you to point to the reason that one is indeed as you describe, and th .......
339: Tube DIY Asylum, RE: Rosenblit Also Got This Wrong (0.00)
Posted by PakProtector on 2021-06-14, 06:19:05 (50.4.127.98)
Those two bits are symmetrical. neither cares where the signal comes from because each is loaded identically. IOW, try and show how the bit with the grid grounded is actually different from the one we .......
340: Tube DIY Asylum, RE: Rosenblit Also Got This Wrong (0.00)
Posted by PakProtector on 2021-06-14, 06:00:35 (50.4.127.98)
Its cathode is not grounded. Not even close. On that basis your equation set needs attention. cheers, Douglas .......
341: Tube DIY Asylum, RE: Rosenblit Also Got This Wrong (0.00)
Posted by PakProtector on 2021-06-14, 05:58:11 (50.4.127.98)
The ccs is not to force equal currents through the tubes. It is to enforce its quantity. For reasonably matched sections( say a 5687 ), the CCS is not going to do anything to enhance the match. It wil .......
342: Tube DIY Asylum, Dave... (0.00)
Posted by PakProtector on 2021-06-14, 03:20:24 (50.4.127.98)
I do believe that the amount of compensation in terms of resistor value suggested by Mr. Broski precludes that conclusion. IIRC, one of us posted the suggested/required plate load resistor compensatio .......
343: Tube DIY Asylum, RE: Rosenblit Also Got This Wrong (0.00)
Posted by PakProtector on 2021-06-14, 03:13:16 (50.4.127.98)
There are ways to turn up the gain of the pentode section that don't have to raise the output impedance. These do require silicon current regulators, which I do recall are contrary to the religious te .......
344: Tube DIY Asylum, RE: Cap Value (0.00)
Posted by PakProtector on 2021-06-13, 15:08:35 (23.125.73.217)
It is also easy enough to recognize the impossibility of said thought experiments, and move the heck on. cheers, Douglas .......
345: Tube DIY Asylum, RE: Rosenblit Also Got This Wrong (0.00)
Posted by PakProtector on 2021-06-13, 11:47:53 (23.125.73.217)
It helps me to think of the LTP as a composite. It is like a grounded cathode amp for the input stage, and a grounded grid for the second. They are joined( ideally ) at the cathode node and taken to g .......
346: Tube DIY Asylum, RE: Cap Value (0.00)
Posted by PakProtector on 2021-06-13, 06:50:54 (23.125.73.217)
Once more, since this seems to be worth your time, set up and conduct an experiment or three. I have not seen a capacitor of infinite capacitance yet...not seen a cap with zero series resistance eithe .......
347: Tube DIY Asylum, RE: Cap Value (0.00)
Posted by PakProtector on 2021-06-13, 03:08:18 (23.125.73.217)
That practice of 'book-ending' is indeed useful. Define the small cap limit, and the large cap limit. However, the basis on which those 'limits' are set are not as solid as you think. Recognizing that .......
348: Tube DIY Asylum, RE: Fools Errand. (0.00)
Posted by PakProtector on 2021-06-11, 15:54:50 (23.125.73.217)
Show the answer then. seems simple enough. Do take pics. Are you sure 1F is enough? How carefully are you going to be measuing AC( or lack of ) across it? Douglas .......
349: Tube DIY Asylum, RE: by ears ... (0.00)
Posted by PakProtector on 2021-06-11, 14:11:55 (23.125.73.217)
I can't think of a worse insult. cheers, Douglas .......
350: Tube DIY Asylum, RE: what to avoid ... (0.00)
Posted by PakProtector on 2021-06-11, 12:53:04 (23.125.73.217)
so it *APPEARS* you know better and then write the idiocy anyway. It is therefore all suspect. It could be that you'll eventually wise up. there are a few who know what's what who used to follow thusl .......
351: Tube DIY Asylum, RE: Why bias taps on power xmfr? (0.00)
Posted by PakProtector on 2021-06-11, 03:09:15 (50.4.127.98)
The bias rail output Z should be considered along with the grid resistance, and dropping a lot of voltage with a resistor is not going to help. If I could get them easily, I'd like a few taps along t .......
352: Tube DIY Asylum, it *IS* a 12AU7... (0.00)
Posted by PakProtector on 2021-06-11, 03:06:24 (50.4.127.98)
and with a CCS deserving the name, equal plate resistors are going to deliver equal output voltages. 12AU7 or not. Their relationship to the input is however in question...6CG7 and 6SN7 will do a bit .......
353: Tube DIY Asylum, RE: the question needs more clarification ... (0.00)
Posted by PakProtector on 2021-06-09, 12:41:05 (50.4.127.98)
Denis is so far over the line he can no longer see it. Given the duration of his writing nonsense on this forum, I am quite willing to bet he has forgotten what it even looked like. No action need be .......
354: Tube DIY Asylum, RE: Fools Errand. (0.00)
Posted by PakProtector on 2021-06-09, 06:46:15 (50.4.127.98)
The bit that seems missing is, if the cap gets sufficiently large, it is no longer matching the idealized schematic with just a plate on each side of the circuit. There is capacitance to other stuff. .......
355: Tube DIY Asylum, RE: Double Talk! (0.00)
Posted by PakProtector on 2021-06-09, 04:10:49 (50.4.127.98)
The caps are only good if DF uses them. If they have not been touched by DF, they are just crap capacitors. Reminds me of the insanity espoused by somebody who was cutting the leads off chokes to put .......
356: Tube DIY Asylum, Don't fret DT... (0.00)
Posted by PakProtector on 2021-06-08, 18:08:21 (23.125.73.217)
I will never be frustrated by trying to make something that sounds like one of Denis-es amps. True frustration would come from owning one with no ability to build something that actually works. cheers .......
357: Tube DIY Asylum, seems to me (0.00)
Posted by PakProtector on 2021-06-08, 12:46:52 (50.4.127.98)
that somebody of your immense skill would have found a way to do without such troublesome things as capacitors by now. cheers, Douglas .......
358: Tube DIY Asylum, RE: I will soon have TWO monoblocks rebuild with identical all-film caps... (0.00)
Posted by PakProtector on 2021-06-08, 11:43:40 (50.4.127.98)
Knowing what's going on effecting the results is most certainly a thing. Having somebody ABx me on something I am pretty sure makes no difference and discovering one is also a thing... :) cheers, Doug .......
359: Tube DIY Asylum, RE: Fools Errand. (0.00)
Posted by PakProtector on 2021-06-06, 08:34:53 (23.125.73.217)
I did assume that at this level of foolishness that the Proper 3.265 parallel runs of wire were used for listening evals. Douglas .......
360: Tube DIY Asylum, Are you from Montana? (0.00)
Posted by PakProtector on 2021-06-06, 06:06:46 (23.125.73.217)
And on a serious side, 10 uV in front of a moving coil amplifier chain will prove audible. (that was not intentional...LOL) The basic idea that a system that uses a bypass cap should have a Very Large .......
361: Tube DIY Asylum, RE: RIP Fry's Electronics (0.00)
Posted by PakProtector on 2021-06-06, 05:47:56 (23.125.73.217)
And before that, Lafayette... cheers, Douglas .......
362: Tubes Asylum, There is no way I am going to set up a 3-day cathode poisoning event (0.00)
Posted by PakProtector on 2021-06-05, 05:59:11 (23.125.73.217)
After listening to mis-information like this I left a new 866A for two days with its cathode heated. At the end, no conduction what so ever. cheers, Douglas .......
363: Tube DIY Asylum, RE: Unused Pins - 6L6 (0.00)
Posted by PakProtector on 2021-06-03, 03:53:22 (50.4.127.98)
I'd suggest not doing that...then when you find some 7027's you won't have to worry. cheers, Douglas .......
364: Tube DIY Asylum, RE: An Afterthought... (0.00)
Posted by PakProtector on 2021-06-03, 03:50:44 (50.4.127.98)
I recall biasing the Cit. II; setting one tube had a minimal effect on the others. Even its monoblock competitor, the W6m took a fair bit of chasing one tube then the other to get bias levels equalize .......
365: Tube DIY Asylum, RE: Harman Kardon Power Supply Regulation (0.00)
Posted by PakProtector on 2021-06-02, 10:08:23 (50.4.127.98)
The Cit.ii ps is quite stout. Not quite sure about 1% from idle( roughly .3A ) to full power simultaneously( about .9A IIRC ). cheers, Douglas .......
366: Tube DIY Asylum, Brilliant! (0.00)
Posted by PakProtector on 2021-05-28, 13:19:34 (50.4.127.98)
Looks proper to me! cheers, Douglas .......
367: Tube DIY Asylum, Second! (0.00)
Posted by PakProtector on 2021-05-28, 04:57:56 (50.4.127.98)
Can't tell if you did it Right if you don't put up a pic... :) Douglas .......
368: Tube DIY Asylum, RE: Anyone Tried the 6N15P Dual Triode? (0.00)
Posted by PakProtector on 2021-05-27, 06:43:42 (50.4.127.98)
Individual bias for the finals is decidedly a no-brainer. The AC balance pot( assuming there is a pot at the B+ end of the plate loads, wiper to B+). The DC balance I saw an interesting one where the .......
369: Tube DIY Asylum, RE: Anyone Tried the 6N15P Dual Triode? (0.00)
Posted by PakProtector on 2021-05-26, 10:25:17 (50.4.127.98)
It took some samples to get ones I liked the match of for use in cascode LTP's. Resistive loaded was easy. Not that I could tell much from the ones I failed in the cascode test matching...just knowing .......
370: Tube DIY Asylum, RE: Anyone Tried the 6N15P Dual Triode? (0.00)
Posted by PakProtector on 2021-05-24, 03:39:19 (50.4.127.98)
Yah...is the in-circuit, and in detail just what circuit that makes a difference. The type 6H6Pi and some of the 5678 variants that lead my list of good section-section match. I have not tried stuff l .......
371: Tube DIY Asylum, RE: Anyone Tried the 6N15P Dual Triode? (0.00)
Posted by PakProtector on 2021-05-22, 16:23:55 (23.125.73.217)
With resistive loads in LTP service, the match appears quite good. Rig them as the bottom element of a cascode with the plate voltage fixed by the upper element, and they are average. cheers, Douglas .......
372: Tube DIY Asylum, RE: The Details (0.00)
Posted by PakProtector on 2021-05-18, 13:51:48 (50.4.127.98)
" IMO, it's important to get the issue of a suitable chassis resolved before spending a lot of time working through the electronic details." Must respectfully disagree. Once all the details are worked .......
373: Tube DIY Asylum, Second... (0.00)
Posted by PakProtector on 2021-05-12, 09:11:26 (50.4.127.98)
Running without a schematic of the as-built beast is not going to get much useful help generated. Douglas .......
374: Tube DIY Asylum, RE:someone appears to need direct intervention (0.00)
Posted by PakProtector on 2021-05-12, 06:51:32 (50.4.127.98)
"I will bet that a year from now, the MLP will be taking the "art" of SE tube amplifiers to even more "God-like" levels of nuance and refinement" -thus the need for intervention No need for interventi .......
375: Tube DIY Asylum, RE: Seems Fitz has left the building nt (0.00)
Posted by PakProtector on 2021-05-12, 04:47:33 (50.4.127.98)
It could be. Takes some doo-dads to admit moo got followed and the results were perhaps not as advertised...LOL I can see an Instagram written by 'Jeff Medwin's Cow'... :) cheers, Douglas ::: TOPIC:: .......
376: Tube DIY Asylum, LMAO... (0.00)
Posted by PakProtector on 2021-05-12, 04:44:03 (50.4.127.98)
Bronies indeed...LOL cheers, Douglas .......
377: Tube DIY Asylum, RE: MLP copycats ... (0.00)
Posted by PakProtector on 2021-05-11, 16:13:33 (23.125.73.217)
What it is could be labeled as a text-book case of small schwartz syndrome. they seem to specialize in selling the myth that it *MIGHT possibly grow if they do as they're told. No thanks...LOL cheers, .......
378: Tube DIY Asylum, RE: Interesting . . . and Confusing - Some History (0.00)
Posted by PakProtector on 2021-05-10, 17:49:20 (23.125.73.217)
"Few will ever know the reality of their circuits." It is not quite 'few'. It is also not the opinion you infer either. The only time moo took any credit was when the review went well, even if the bui .......
379: Tube DIY Asylum, he was... (0.00)
Posted by PakProtector on 2021-05-08, 18:29:23 (23.125.73.217)
If it were me answering, it would have gone like this: serves ya right. Now an 01A is for sure not a 12AX7, or what ever high mu, high plate Z triode Mooo was fond of, this could be an interesting amp .......
380: Tubes Asylum, Throw it back... (0.00)
Posted by PakProtector on 2021-05-08, 05:41:27 (23.125.73.217)
If it does not sound good, why in the heck would you contemplate spending more money on it? cheers, Douglas .......
381: Tube DIY Asylum, RE: Right, not exactly. (0.00)
Posted by PakProtector on 2021-05-07, 15:56:05 (23.125.73.217)
I did not feel the need to go into detail. Perhaps splitting a hair or two, yes... :) Anyway, very nice machines. cheers, Douglas .......
382: Tube DIY Asylum, It is not VFD... (0.00)
Posted by PakProtector on 2021-05-06, 17:52:21 (23.125.73.217)
That spindle runs on DC. The electronics run the DC output. A 3P motor turns a generator. Full 60 cps on that. The tubes reg the DC for the spindle drive. Putting an induction machine on the spindle, .......
383: Tube DIY Asylum, RE: Check this out - Tube VFD on a 1959 Lathe. (0.00)
Posted by PakProtector on 2021-05-06, 10:54:11 (50.4.127.98)
On the Monarch continuum, those are the top shelf. IIRC the last price of a new one was an eighth of a Million. For a 10"wing, 20" c-c length machine. 'Superb' is a pale, grey, nearly transparent adje .......
384: Tube DIY Asylum, RE: Check this out - Tube VFD on a 1959 Lathe. (0.00)
Posted by PakProtector on 2021-05-06, 03:21:47 (50.4.127.98)
Those 10EE's are brilliant. They weigh a Ton. Well, actually closer to two. I want one. As with all tube gear, need to find one that just needs a bit o' electrical work. If you don't need full power, .......
385: Tube DIY Asylum, RE: Increasing Gain in Respectable Transconductance 7 Pin Mini Types (0.00)
Posted by PakProtector on 2021-05-04, 03:13:43 (50.4.127.98)
those are single elements, yes? Go totally nuts; 6HV5A. mu of 300, gm of 65 mA/V...not a 7-pin though...LOL cheers, Douglas .......
386: Tube DIY Asylum, RE: Cathodyne VS LTP (0.00)
Posted by PakProtector on 2021-05-03, 05:47:03 (50.4.127.98)
If you need the tube CCS, the type 6AC7 should do. There is also a tube cascode, triode on the bottom, pentode on top. This gets remarkably expensive voltage-wise though. I prefer the SS version. A DN .......
387: SET Asylum, Nope... :) (0.00)
Posted by PakProtector on 2021-05-01, 15:26:15 (23.125.73.217)
1955 Hudson Hornet, equipped with a 1958 300D engine. While we are into it, disc brakes all around. Or if you're Colin Chapman-sized, an Esprit S2 with a 220 hp BHW engine. cheers, Douglas ::: TOPIC:: .......
388: Tube DIY Asylum, RE: Cathodyne VS LTP (0.00)
Posted by PakProtector on 2021-05-01, 05:09:58 (23.125.73.217)
It takes a bit of sorting to get 6J6's that match well enough( IMO ) for LTP use. There are Three types, and one is allegedly selected for section-section matching. 6099 I think is one, and 6101 is th .......
389: Tubes Asylum, RE: That's supply & demand, not inflation (nt) (0.00)
Posted by PakProtector on 2021-04-25, 06:15:52 (23.125.73.217)
It is a two part thing...now keep in mind from this 'explanation' that I did not thorough economics courses, nor did I get an A in the ones I had to take for my Mechanical Engineering degrees. Inflati .......
390: Tube DIY Asylum, RE: Only later variants had higher ratings (0.00)
Posted by PakProtector on 2021-04-25, 06:05:17 (23.125.73.217)
If you can tolerate open, go with fuse holder clips. That is the best I have found for the small ones like a 3D21A. cheers, Douglas .......
391: Tube DIY Asylum, RE: Only later variants had higher ratings (0.00)
Posted by PakProtector on 2021-04-24, 17:47:44 (23.125.73.217)
I think the 'GC has also a higher plate dissipation rating( 30w vs 25 at the ccs usage ). Not quite sure that translates well to the 6L6GC that is for sure at least a 30W plate. I need me a ham fest o .......
392: Tube DIY Asylum, RE: Distortion (0.00)
Posted by PakProtector on 2021-04-23, 03:46:33 (50.4.127.98)
Seems like a plan; the 'bunching up' of the plate curves at low current( gm shrinkage ) is unavoidable. Driving the load line through the knee where they bunch up again is avoidable. I put together a .......
393: SET Asylum, RE: another brilliant essay by DF (0.00)
Posted by PakProtector on 2021-04-22, 17:29:10 (23.125.73.217)
you watch entirely too much OAN. Or perhaps one of the more radical ones. Or perhaps the one that calls itself 'NEWS', except when in court, then they say it is opinion and nobody should treat it as n .......
394: Tube DIY Asylum, RE: Distortion (0.00)
Posted by PakProtector on 2021-04-22, 10:15:37 (50.4.127.98)
The distortion performance is not due to g2 voltage, but what g2 voltage does to the performance envelope, and where the load line is driven across the characteristic plate curves. It could be this w .......
395: Tube DIY Asylum, RE: Only later variants had higher ratings (0.00)
Posted by PakProtector on 2021-04-22, 09:19:35 (50.4.127.98)
and there are late model GB that I am sure are actually of the GC line...or perhaps even the 35W 7581A line... :) cheers, Douglas .......
396: Tube DIY Asylum, RE: Transformer Interaction - Fact or Fiction? (0.00)
Posted by PakProtector on 2021-04-21, 17:09:07 (23.125.73.217)
The OPT is 90 degrees from both choke and power. Power and choke are the same orientation. I pulled the choke cover plate to confirm. cheers, Douglas .......
397: Tube DIY Asylum, RE: 6L6 Specs (0.00)
Posted by PakProtector on 2021-04-21, 08:07:58 (50.4.127.98)
At a constant g2 voltage, the value of the voltage is the 'matching' quantity to set the g1=0V operating envelope to the load line( what ever that happens to be), based on a-a reflected load, and Clas .......
398: Tubes Asylum, RE: Why current production? (0.00)
Posted by PakProtector on 2021-04-16, 16:13:15 (23.125.73.217)
Could be indeed. Now if those were 6LF6's... :) cheers, Douglas .......
399: Tube DIY Asylum, RE: Yep. nt (0.00)
Posted by PakProtector on 2021-04-16, 01:34:56 (23.125.73.217)
Nah, only 31 x 11. Douglas .......
400: Tube DIY Asylum, RE: Yep. nt (0.00)
Posted by PakProtector on 2021-04-15, 16:49:32 (23.125.73.217)
This is a big little amp. S271S output. S37 choke, Beckmann D/U power iron, and 6CJ3 rectifiers. Input stage is 25HX5. Balanced input. It is about as heavy as I am comfortable with... :) cheers, Do .......
401: Tube DIY Asylum, RE: Transformer Interaction - Fact or Fiction? (0.00)
Posted by PakProtector on 2021-04-15, 03:37:16 (50.4.127.98)
Just keep in mind the test rig John Atwood used for this testing. I talked to him about this one year at The Mill, and we agreed that driving the secondary with a set source impedance( a SS amp and se .......
402: SET Asylum, RE: What this Says (0.00)
Posted by PakProtector on 2021-04-14, 08:29:20 (50.4.127.98)
Was going to say something like, 'get better VT linestages'. I have yet to want better than I can currently build. Does not stop me from trying, and the next bit I plan to try is DH stuff... :) Now I .......
403: Tube DIY Asylum, RE: I'm always "go big or go home" (0.00)
Posted by PakProtector on 2021-04-12, 03:41:14 (50.4.127.98)
With existing stuff like a Dynaco chassis, there is not much room for 'improvement'. Just a bit too much of 'built to price point' for my taste. Now a St.70 converted to monoblock operation is quite a .......
404: Tube DIY Asylum, NOPE! (0.00)
Posted by PakProtector on 2021-04-12, 03:37:14 (50.4.127.98)
The last pair of amps I built run a UTC S37 and a big C for its single-stage LC filter. 550 mA/8 Hy. Tested as an input choke delivering 650V at 350 mA without any signs of distress. Not overkill at a .......
405: Tube DIY Asylum, RE: Some people can't wait for Mouser or Digi-Key orders (0.00)
Posted by PakProtector on 2021-04-11, 06:28:42 (23.125.73.217)
Convenient...but I am quite sure that the particular bit I would need would be either sold out, or not there in the first place. Work up your BOM, and confirm inventory...*THEN make a single order. Th .......
406: SET Asylum, RE: another brilliant essay by DF (0.00)
Posted by PakProtector on 2021-04-10, 19:51:25 (23.125.73.217)
You know denis, unfortunately it is too risky for the rest of us that you be precluded from recieving treatment when the 'scam' takes a fatal bite out of your backside. If it were not for the fact you .......
407: Tube DIY Asylum, RE: kinda sucked huh? (0.00)
Posted by PakProtector on 2021-04-09, 04:13:18 (50.4.127.98)
I evaded nothing. And since you have never built an amp with an A440/441, and likely never even heard one( though you did neglect to answer that question), your opinion's value has just been defined. .......
408: Tube DIY Asylum, RE: kinda sucked huh? (0.00)
Posted by PakProtector on 2021-04-08, 17:34:40 (23.125.73.217)
And you have ever listened to one to know they're brilliant? Beyond being unstable, they just don't sound all that good. The Chicago CFB outputs OTOH, have been universally brilliant. cheers, Douglas .......
409: Tube DIY Asylum, RE: kinda sucked huh? (0.00)
Posted by PakProtector on 2021-04-08, 15:01:16 (23.125.73.217)
or if you even heard an amp built around them... :) cheers, Douglas .......
410: Tube DIY Asylum, RE: kinda sucked huh? (0.00)
Posted by PakProtector on 2021-04-08, 14:59:35 (23.125.73.217)
You never did say what you built with your A441's. cheers, Douglas .......
411: Tube DIY Asylum, RE: Transformer Interaction - Fact or Fiction? (0.00)
Posted by PakProtector on 2021-04-08, 10:01:54 (50.4.127.98)
When rigged for CFB, they developed a large low frequency peak with the addition of 3% plate to grid FB around the finals. They also lacked the clarity/detail that smaller Dynaco outputs like the A43 .......
412: Tube DIY Asylum, RE: Transformer Interaction - Fact or Fiction? (0.00)
Posted by PakProtector on 2021-04-07, 17:59:39 (50.4.127.98)
There are a few families of OPT's that like the 9R tap. The Peerless 20-20 Plus comes to mind. Two 4R, CT secondaries. 1, 4, 9 and 16R are possible. Should have said, *some of the 20-20 Plus. Take for .......
413: Tubes Asylum, RE: Rectifer Tube Choice for easy on the other components............. (0.00)
Posted by PakProtector on 2021-04-05, 03:59:35 (50.4.127.98)
It is a matter of how you describe 'stress'. The DH models like 5R4, 274, 5Y3 and 5U4 are all DH, and deliver voltage almost instantaneously. If this is an issue, then an IDH would be called for. If i .......
414: Tube DIY Asylum, RE: If you do not trust simulations do not use simulations. (0.00)
Posted by PakProtector on 2021-04-04, 17:54:11 (23.125.73.217)
If your tube model is good, it should have no troubles creating curves at various tap percentages, and starting points( variable B+ that is). If it can do that, the TX model is easy... cheers, Douglas .......
415: Tube DIY Asylum, RE: Transformer Interaction - Fact or Fiction? (0.00)
Posted by PakProtector on 2021-04-03, 18:07:25 (23.125.73.217)
Yes the were all on the top. The OPT was a canned A441 Dynaco. That beast is no longer with me...the big Dynaco OPT's have all kinda sucked IMO. cheers, Douglas .......
416: Tube DIY Asylum, RE: Transformer Interaction - Fact or Fiction? (0.00)
Posted by PakProtector on 2021-04-03, 05:32:12 (23.125.73.217)
Did not consider this on my first build. Huge Irons, and I had the power facing the same way as the output. Choke in the middle facing 90-degrees to both. hum was low, but as soon as I lit the power T .......
417: Tube DIY Asylum, RE: 5u4 choke input question (0.00)
Posted by PakProtector on 2021-04-02, 10:07:29 (23.125.73.217)
The power tx resistances also play a part in this repetitive current. It is quite possible to exceed the repetitive current with a 40 uF cap... :) cheers, Douglas .......
418: Tubes Asylum, RE: Please Don't Buy Any 5AR4s (0.00)
Posted by PakProtector on 2021-04-02, 06:32:20 (23.125.73.217)
The olde f32 GZ34 had as many missing pins as possible; did they eliminate another with an internal connection? cheers, Douglas .......
419: Tube DIY Asylum, RE: Cathodyne Protection (0.00)
Posted by PakProtector on 2021-04-01, 15:38:01 (23.125.73.217)
I could see a bit of a pop when that puppy blinks out. cheers, Douglas .......
420: SET Asylum, Well... (0.00)
Posted by PakProtector on 2021-04-01, 10:07:39 (50.4.127.98)
I did get my pair of S-271-S built. Big TV sweeps for finals, and 14W, vertical deflection pentodes for the front end taking balanced signal and sharing a common cathode resistor. I suppose the next .......
421: Tubes Asylum, RE: how to connect transformer (0.00)
Posted by PakProtector on 2021-03-31, 08:35:25 (50.4.127.98)
Oh god no. The only item of interest is the cathode current. Are you currently over the limit? cheers, Douglas .......
422: SET Asylum, By now it ought to be quite obvious.... (0.00)
Posted by PakProtector on 2021-03-31, 04:18:48 (50.4.127.98)
Denis is building processors that happen to be capable of delivering power to a speaker. His operating point has made this quite clear. He has settled on finding a means to deliver the sonics he desir .......
423: High Efficiency Speaker Asylum, I got yer 'Girls with guitars' (0.00)
Posted by PakProtector on 2021-03-30, 15:10:05 (23.125.73.217)
https://www.youtube.com/watch?v=qoPqO-nDrQQ The Trooper Douglas .......
424: High Efficiency Speaker Asylum, RE: Terms and examples please (0.00)
Posted by PakProtector on 2021-03-30, 09:08:35 (50.4.127.98)
I'll take you up on that at your convenience. I'll bring an amp or two... :) Soooo...given the 'location' of the driver is supposed to be at 20% of the way up the tube, it looks like extending the tub .......
425: Tube DIY Asylum, RE: Bias Pots (0.00)
Posted by PakProtector on 2021-03-30, 08:50:35 (50.4.127.98)
The question I would put to you is what is wrong with those? I'll suspect dissipation, as you may have a substantial negative supply these are put across. In that case, let me suggest a series R to dr .......
426: High Efficiency Speaker Asylum, RE: Terms and examples please (0.00)
Posted by PakProtector on 2021-03-29, 12:04:26 (50.4.127.98)
Up to 80-100cps. Douglas .......
427: High Efficiency Speaker Asylum, RE: Yep.... (0.00)
Posted by PakProtector on 2021-03-29, 03:17:04 (50.4.127.98)
It was either that or Purple. As a, color, shade of purple gray... cheers, Douglas .......
428: Tube DIY Asylum, RE: PEM Nuts (0.00)
Posted by PakProtector on 2021-03-28, 17:35:31 (23.125.73.217)
It was closest to hand. And it was the partial for a car I no longer have... :) O1 is nice that way, even a rushed, poorly executed heat treat will still leave it a useful tool, though perhaps not qui .......
429: High Efficiency Speaker Asylum, RE: Yep.... (0.00)
Posted by PakProtector on 2021-03-28, 15:39:43 (23.125.73.217)
"That apparatus is used in front of a midrange or high frequency driver." Thanks Captain Obvious. length was my first clue. Diameter was the second. I appreciate all the help you have offered here, re .......
430: Tube DIY Asylum, RE: PEM Nuts (0.00)
Posted by PakProtector on 2021-03-28, 15:37:38 (23.125.73.217)
For pressing onto a flat anvil, this tool has a nub about 80% of the nuts thickness and is a few thou under the minor dia of the nut's threads. Goal is to keep the beast something like straight and li .......
431: Tube DIY Asylum, RE: PEM Nuts (0.00)
Posted by PakProtector on 2021-03-28, 15:34:46 (23.125.73.217)
O1 has alloy to make it harden at a slower chill rate. Besides, this procedure you propose is a wee bit much at work... Douglas .......
432: High Efficiency Speaker Asylum, RE: Yep.... (0.00)
Posted by PakProtector on 2021-03-28, 07:57:17 (23.125.73.217)
So, with no K-slot, it is going to be on-off-on...every time a quarter wavelength comes into resonance. This pair of examples have the slot going full length. What does the response look like when it .......
433: High Efficiency Speaker Asylum, RE: Terms and examples please (0.00)
Posted by PakProtector on 2021-03-28, 06:52:10 (23.125.73.217)
If I could find a set of sim software that had an acceptable learning curve I'd probably ask fewer questions. "What you refer to 'de-comb' with stuffing is actually suppression of pipe harmonics, whi .......
434: Tube DIY Asylum, RE: PEM Nuts (0.00)
Posted by PakProtector on 2021-03-28, 06:40:48 (23.125.73.217)
We use these things, and as noted the hole they fit into should be properly sized. I will inquire as to the source Monday. For little ones going into AL, your 1Ton sounds quite capable. I turned the t .......
435: High Efficiency Speaker Asylum, RE: Terms and examples please (0.00)
Posted by PakProtector on 2021-03-27, 18:10:45 (23.125.73.217)
I think we perhaps are contemplating different things. I am looking at something like El Pipo. Woofer at one of a quarter wave( of minimum freq ) long tube. Comes on at when L=Lambda/4, then Lambda/2, .......
436: Tube DIY Asylum, RE: PEM Nuts (0.00)
Posted by PakProtector on 2021-03-27, 16:06:29 (23.125.73.217)
McMaster Carr comes to mind. cheers, Douglas .......
437: High Efficiency Speaker Asylum, RE: Terms and examples please (0.00)
Posted by PakProtector on 2021-03-27, 13:10:01 (23.125.73.217)
Practical is a matter of definition. That I need my truck to go get the bits is about as bad as it gets. Space to hang 14-15' is not an issue either... :) A bit of guidance on the notch at the dischar .......
438: High Efficiency Speaker Asylum, Terms and examples please (0.00)
Posted by PakProtector on 2021-03-27, 10:30:33 (23.125.73.217)
Gearing up to build a sub woofer. Transmission line, made from some long bits of 12" sonotube. What sort of *roughly triangular shaped notch should be cut in the discharge end to de-comb its response? .......
439: High Efficiency Speaker Asylum, RE: Start up of Pratt & Whitney R-2800 Double Wasp WW2 Hellcat engine (0.00)
Posted by PakProtector on 2021-03-27, 10:12:22 (23.125.73.217)
The Germans also thought that a trace amount of Indium from the bearing analysis was a contaminant, and not a design feature. Also, there is a fair gap in the capability of the cast head R2800's and t .......
440: Tube DIY Asylum, RE: Another Transformer Topic (0.00)
Posted by PakProtector on 2021-03-26, 11:21:46 (50.4.127.98)
I tend to picture this as 'figure 8's', the power Iron is laying on its side and the two outputs are vertical. The center leg of all three are parallel...which I try to avoid. The top and bottom of th .......
441: Tube DIY Asylum, RE: " (edit... oops.. I see PJ said this above...)"... (0.00)
Posted by PakProtector on 2021-03-25, 14:28:56 (23.125.73.217)
I thought your 25A of 5V for the 304TL would take the cake as far as so called 'reasonable' amp projects would go... :) Douglas .......
442: Tube DIY Asylum, RE: 7-Pin Miniatures (0.00)
Posted by PakProtector on 2021-03-25, 02:01:59 (23.125.73.217)
Oh yes, I hear you...and whilst disagreeing on the point, at least it is a POV that makes some sense. Would still like you to hear what they can do, just in case the preference of yours has some basis .......
443: SET Asylum, so then, what is the best car? (0.00)
Posted by PakProtector on 2021-03-24, 18:11:03 (23.125.73.217)
Several...LOL One should be a truck, one should be a multi-passenger rolling arm chair, and one should be a Caterham...and of course do feel free to fill in the gaps with more cars. A 1969 Daytona Ch .......
444: Tube DIY Asylum, RE: 7-Pin Miniatures (0.00)
Posted by PakProtector on 2021-03-24, 17:59:05 (23.125.73.217)
With a CCS properly configured, it is possible to get nearly what ever mu you wish from a pentode...and if you chose the Right ccs, a low impedance output that will drive anything( nearly ), is also p .......
445: Tube DIY Asylum, RE: VR Tubes for Screens (0.00)
Posted by PakProtector on 2021-03-24, 05:27:57 (50.4.127.98)
Sounds like a fine plan; having the g2 voltage change under near full power use looks like the worst time for it to happen. I can tell you that with 6550 swapped into a 6146 amp presented a larger g2 .......
446: Tube DIY Asylum, RE: 7-Pin Miniatures (0.00)
Posted by PakProtector on 2021-03-23, 16:47:37 (23.125.73.217)
Given how well the 6V6GTA works as a signal tube, I bet that the 6AQ5 will also do quite well. cheers, Douglas .......
447: Tube DIY Asylum, RE: VR Tubes for Screens (0.00)
Posted by PakProtector on 2021-03-23, 09:01:01 (50.4.127.98)
I think I will suggest examining the data sheet showing g2 current on the 6L6GC. At 250V on the screen I see nearly 20 mA per...and it has been my experience that the regulation of a VR150 covers a wi .......
448: Tube DIY Asylum, RE: VR Tubes for Screens (0.00)
Posted by PakProtector on 2021-03-23, 05:22:18 (50.4.127.98)
I tend to want more current than a VR tube shunt reg will be able to supply. I also want a bit more detail, say more than 75, 90, 105 and 150V multiples. A source follower, hung from a voltage divider .......
449: Tubes Asylum, not so fast... :) (0.00)
Posted by PakProtector on 2021-03-19, 15:41:29 (23.125.73.217)
It would seem that there is plenty of use for romantic nostalgia. It is a means of separating holders of it from their $$$. cheers, Douglas .......
450: Tube DIY Asylum, RE: LT Spice (0.00)
Posted by PakProtector on 2021-03-19, 15:36:36 (23.125.73.217)
has it got any of the cool tubes? 6JS6C perhaps? How big is its library, and where might one find it? cheers, Douglas .......
451: SET Asylum, RE: they are not ready for it ... (0.00)
Posted by PakProtector on 2021-03-15, 18:02:44 (23.125.73.217)
Man, denny couldn't tune a pentode screen grid voltage to a load for a million dollars. I think the very first amp I assembled from scratch was built around a set of A441 outputs. KT90 type III from .......
452: SET Asylum, RE: Are you parodying yourself? (0.00)
Posted by PakProtector on 2021-03-15, 17:52:08 (23.125.73.217)
I will. I have stuff to build...:) A pair of Chicago BO-14's has been mocking me for a bit, as has a set of custom S265Q...and some nice pentodes and medium-sized power triodes. cheers, Douglas ::: T .......
453: Tube DIY Asylum, RE: 7199 VS 6AN8 (0.00)
Posted by PakProtector on 2021-03-15, 17:32:40 (23.125.73.217)
For a 'one at a time' builder, who can tune up the next tube change upon wear-out with a simple resistor swap, it is not so bad. As you suggest, for a kit supplier, it is probably less than practical. .......
454: Tube DIY Asylum, RE: Well... (0.00)
Posted by PakProtector on 2021-03-15, 17:24:33 (23.125.73.217)
It could be that it sounded better to who ever decided it should be built that way. Or it could be redundant. By the usual means of reasoning, it could probably live without. Not quite feeling like sa .......
455: Tube DIY Asylum, RE: 7199 VS 6AN8 (0.00)
Posted by PakProtector on 2021-03-15, 14:40:00 (23.125.73.217)
I have found these very stable with a bypssed dropping R to their g2. Quite a few different builds, and the once I found it unstable one of the pair failed a gas test... :) Plate voltage is important, .......
456: Tube DIY Asylum, Re: 5687 ? (0.00)
Posted by PakProtector on 2021-03-15, 08:18:53 (50.4.127.98)
Having the split load behind it limits the load on the pentode. You can get away with murder now, and can likely do without something like a 6CL6 or an EL84... :) Won't stop me from suggesting either. .......
457: Tube DIY Asylum, Re: 5687 ? (0.00)
Posted by PakProtector on 2021-03-15, 04:12:31 (50.4.127.98)
I think one section will be adequate. Drop resistor values from the commercial 12AU7 implementation. How much is up to you, and you can go pretty far without either exceeding plate dissipation or DC c .......
458: Tube DIY Asylum, Well... (0.00)
Posted by PakProtector on 2021-03-14, 18:01:46 (23.125.73.217)
The triode above the CF is just floating there like a cascode, but instead of it holding a constant voltage above ground, it is to keep the exct voltage above the lower one. PSRR is improved because a .......
459: Tube DIY Asylum, RE: what Doug said, save for I opt for 6267 and 5687, not aware of any octals that can match in performance~nT (0.00)
Posted by PakProtector on 2021-03-14, 17:24:41 (23.125.73.217)
That 5687 is also brilliant...had the 'single element' bottle blinders on. There is of course 6H6 and 6H30... :) Go totally nuts anyway, IFF you have heater budget anyway. I am really liking small pow .......
460: SET Asylum, RE: Are you parodying yourself? (0.00)
Posted by PakProtector on 2021-03-14, 16:36:23 (23.125.73.217)
yah...either we beat it into submission with vaccination and masks, or it changes again, and then more will die...maybe a lot more. The longer it is multiplying through the population, the higher the .......
461: SET Asylum, RE: Are you parodying yourself? (0.00)
Posted by PakProtector on 2021-03-14, 16:07:05 (23.125.73.217)
If it were not for the idea that failing to vaccinate folks like that who finally ask for it would make me less safe, I would love to gather up all the idiots who have *EVER written things like thatan .......
462: SET Asylum, I suggested no such thing. (0.00)
Posted by PakProtector on 2021-03-14, 15:17:50 (23.125.73.217)
Theory, and calculation will get you what 'Art' can't. Theory and calculation are not exclusive. Blending in Art, as you claim to do, most certainly is. it is only the 'Art' as you have been using it .......
463: SET Asylum, RE: New 45 SET Amps - can they play wideband? (0.00)
Posted by PakProtector on 2021-03-14, 15:10:38 (23.125.73.217)
"A good item for discussion here would be: at what voltage should G-2 be operated relative to the B+ that is on the plate? No, a good question would be, where should the g2 voltage be for a given B+ a .......
464: Tube DIY Asylum, RE: 7199 VS 6AN8 (0.00)
Posted by PakProtector on 2021-03-14, 15:01:59 (23.125.73.217)
I'd rather split them up. The 6EJ7/EF184 as part of it, and something like a 12A4 for the split load section. cheers, Douglas .......
465: Tube DIY Asylum, RE: A true DIYer does not complain... (0.00)
Posted by PakProtector on 2021-03-12, 06:57:49 (50.4.127.98)
you is quite welcome to yer opinion. If taken just a wee bit further, an order for an amplifier could result in the delivery of a flaming bag of dog poop and you'd say that 'fixing it' so it functione .......
466: SET Asylum, RE: Nice speech Dennis but (0.00)
Posted by PakProtector on 2021-03-11, 05:14:57 (50.4.127.98)
"Enjoying audio is more Art than calculation or theory." That is a big, steaming pile of Marketing. Calculation and Theory are required. You won't get a speaker matching its cabinet/horn, etc without .......
467: Tube DIY Asylum, RE: Super Linear Cathode Follower? (0.00)
Posted by PakProtector on 2021-03-11, 03:28:04 (50.4.127.98)
That there question sir is entirely different from the 'how does this circuit work?' question...- :) The 'is this needed', or 'is this a good idea' is of course open to discussion. cheers, Douglas :: .......
468: Tube DIY Asylum, RE: Super Linear Cathode Follower? (0.00)
Posted by PakProtector on 2021-03-10, 17:55:08 (23.125.73.217)
Nah...that stack of three is a current reg on the bottom, and a cathode follower with a screen section on top. Pretend its upper plate is that of a pentode, and its grid is the screen of said pentode( .......
469: Tube DIY Asylum, RE: Are you serious? (0.00)
Posted by PakProtector on 2021-03-08, 11:54:33 (50.4.127.98)
Tell you what; I exceeded the h-k voltage on my type 842's please let me in on a solid source of this tube. and for $20/tube please. cheers, Douglas .......
470: Tube DIY Asylum, RE: What happens to your tube amplifier at power up (0.00)
Posted by PakProtector on 2021-02-28, 15:19:48 (23.125.73.217)
"widely accepted", "many people believe" and statements of this sort should not be considered as indicators of reality. cheers, Douglas .......
471: Tubes Asylum, RE: Valve preamplifier biasing (0.00)
Posted by PakProtector on 2021-02-27, 04:45:07 (23.125.73.217)
The 7.5 uF, 330V ASC are not the worst linestage coupling caps. Not even close. They'll tolerate any reasonable B+ required, are easy to get and are not very big... :) cheers, Douglas .......
472: Tube DIY Asylum, RE: A practical way to use a surplus PP transformer as a choke for SE DIY (0.00)
Posted by PakProtector on 2021-02-25, 03:12:30 (50.4.127.98)
and these torroids can tolerate how much DC before their L value goes to half, and then a quarter? cheers, Douglas .......
473: Tube DIY Asylum, RE: A practical way to use a surplus PP transformer as a choke for SE DIY (0.00)
Posted by PakProtector on 2021-02-24, 14:50:11 (23.125.73.217)
'flat impedance extending well beyond the audio band' Really? The self resonant point is usually smack in the middle of the 20-20kHz window, is it not? cheers, Douglas .......
474: SET Asylum, RE: sv811-10 (0.00)
Posted by PakProtector on 2021-02-22, 03:29:41 (50.4.127.98)
I'd be slightly more concerned with getting replacement SV811-10 tubes. Or is this not such a big deal these days? cheers, Douglas .......
475: Tube DIY Asylum, Well...that makes sense (0.00)
Posted by PakProtector on 2021-02-22, 03:26:00 (50.4.127.98)
Have to say that I dislike series grid resistance on general principles. No sense going after lowest possible driver impedance, and then throwing it away thusly, but it seems to serve a purpose... :) .......
476: Tube DIY Asylum, RE: "Grid Leak Resistor" (0.00)
Posted by PakProtector on 2021-02-21, 04:49:09 (23.125.73.217)
They even drew the pent up electrons on the wrong side of the grid...LOL cheers, Douglas .......
477: Tube DIY Asylum, RE: "Grid Leak Resistor" (0.00)
Posted by PakProtector on 2021-02-21, 04:47:15 (23.125.73.217)
Same goes for 'driver'. That term started out as the last stage ahead of a tube expected to require grid current( and capable of delivering it). By now, it seems to mean the stage ahead of power tubes .......
478: Tube DIY Asylum, RE: A caution (0.00)
Posted by PakProtector on 2021-02-20, 14:49:31 (23.125.73.217)
As long as you don't start imbalancing the op amps by increasing their bias towards one side( usually the negative rail ). I think... cheers, Douglas .......
479: Tube DIY Asylum, RE: come on...spill da beans (0.00)
Posted by PakProtector on 2021-02-19, 16:22:13 (23.125.73.217)
"EL84's? I've got about 28 of them" And you suggest I hoard tubes...LOL It could be I have that many of one type...likely either 6AH4 or 6BL7. Certainly nothing interesting in that qty... :) perhaps u .......
480: Tube DIY Asylum, RE: come on...spill da beans (0.00)
Posted by PakProtector on 2021-02-19, 03:20:17 (50.4.127.98)
AM, I don't think my collection of tubes is exceptional, very extensive or all that valuable. The stuff I use is for the most part quite inexpensive, or rare when I found it( and also inexpensive on a .......
481: Tube DIY Asylum, RE: come on...spill da beans (0.00)
Posted by PakProtector on 2021-02-18, 09:03:46 (50.4.127.98)
Maybe use of obscure tubes, but if a response is obscure, it is either a joke, or you did not get it. Besides, I am well stocked for my next n projects, of which I will likely accomplish at best n-2 .......
482: Tube DIY Asylum, come on...spill da beans (0.00)
Posted by PakProtector on 2021-02-18, 03:44:37 (50.4.127.98)
what output tube are you building around? cheers, Douglas .......
483: Tubes Asylum, HA! (0.00)
Posted by PakProtector on 2021-02-12, 18:43:58 (23.125.73.217)
There is lots and lots to look out for. I'd love to find something like that, and I missed something similar by about 6 months. No idea just how badly I missed, but given the description, it was not s .......
484: Tube DIY Asylum, RE: initial thoughts (0.00)
Posted by PakProtector on 2021-02-08, 17:30:48 (23.125.73.217)
To go full 'tester', I'd suggest some more switches. Like one to add/remove LED's from the bias string. And perhaps add/remove resistance from the cathode. Operating point movers so to say. That then .......
485: Tube DIY Asylum, RE: After you put your eyes out changing tubes... (0.00)
Posted by PakProtector on 2021-02-08, 15:42:12 (23.125.73.217)
Doooood, if you're worried about those, I have to wonder how you manage to brush your teeth without stabbing yourself some where important. cheers, Douglas .......
486: Tube DIY Asylum, RE: At the other end of the beauty stakes (0.00)
Posted by PakProtector on 2021-02-08, 15:38:46 (23.125.73.217)
It is all about the Matrix...consider this to be a tube tester. Type 27 with choke load, ccs load, resistive load, and then apply it to the means to bias the tube...then add a few more tubes. I'd sugg .......
487: Tube DIY Asylum, RE: At the other end of the beauty stakes (0.00)
Posted by PakProtector on 2021-02-07, 17:56:14 (23.125.73.217)
That was one sweet project... :) Is one sweet project. Now an additional wrinkle might be switching the loads, inductive, resistive, CCS... Takes a wee bit to go between a choke load, and a resistor. .......
488: Tube DIY Asylum, RE: off the list ... (0.00)
Posted by PakProtector on 2021-01-28, 16:52:31 (23.125.73.217)
I have no bitter feelings about Jeff. Just glad he does not think I want to read his opinions. cheers, Douglas .......
489: Tube DIY Asylum, HA! may God help them... (0.00)
Posted by PakProtector on 2021-01-21, 11:21:51 (50.4.127.98)
the folk on his list are welcome to him. Quite glad I am no longer receiving email from him. the people on His List are welcome to exalt him as a martyr to their hearts desire. Just like the Lottery .......
490: Tube DIY Asylum, RE: Q About Elevated Heaters (0.00)
Posted by PakProtector on 2021-01-19, 05:57:41 (50.4.127.98)
Your goal as I understand it is to saturate the heater-cathode diode, which thanks to the insulation is a high resistance circuit. If the diode is adequately saturated, then an additional bit of AC is .......
491: Tube DIY Asylum, RE: That is not a problem... (0.00)
Posted by PakProtector on 2021-01-15, 15:36:56 (23.125.73.217)
'as the diode loss in W is not easy to define.' Man, Ohm's Law, and the capacitor equation relating current to voltage is about it. Go ahead and be conservative about choosing the fwd drop. This assum .......
492: Tube DIY Asylum, RE: Thanks muchly! nt. (0.00)
Posted by PakProtector on 2021-01-14, 15:47:45 (23.125.73.217)
The fun part would be to model it. Small time steps. Excel is more than capable of coming close. I suspect the free variant of PSpice is going to have no trouble, and you can jigger parameters and see .......
493: Tube DIY Asylum, RE: That is not a problem... (0.00)
Posted by PakProtector on 2021-01-14, 10:07:27 (50.4.127.98)
A 5A SiC Schottky is going to be good for between 25 and 30A of repetitive peak current. Depends on how big the cap is; a huge cap is going to have higher peak currents, but the usual plate supply tra .......
494: Tube DIY Asylum, RE: HV Supply Wish List (0.00)
Posted by PakProtector on 2021-01-14, 03:51:19 (50.4.127.98)
Sounds like a fine idea. I'd find some way to try this; I have no issue with attempting to lighten a geetar amp. I'd also probably just try a build with a tube that would be happy with a 300V B+ for t .......
495: Tube DIY Asylum, That is not a problem... (0.00)
Posted by PakProtector on 2021-01-13, 15:33:43 (23.125.73.217)
I don't build anything but L-C filters. Critical type, with chokes happy dealing with the AC content. The SS stuff still has a solid spread between max and avg. As you noted, the Schottky is about 5:1 .......
496: Tube DIY Asylum, RE: Why no snubbers ? (0.00)
Posted by PakProtector on 2021-01-13, 09:06:43 (50.4.127.98)
I am not seeing a need to complicate this any further than is needed. A pair of UF4007 will get you 2kV of PIV. I happen to prefer from a technical POV, to use 1k2V SiC Schottky diodes from Cree. I c .......
497: Tube DIY Asylum, RE: FET-Triode Cascade (0.00)
Posted by PakProtector on 2021-01-12, 05:48:46 (50.4.127.98)
hence the suggestion for an easy gain adjustment, and plenty of drive capacity. cheers, Douglas .......
498: Tube DIY Asylum, RE: FET-Triode Cascade (0.00)
Posted by PakProtector on 2021-01-11, 03:13:07 (50.4.127.98)
Aside from using a FET as a single device input stage, no...go right on and try it. cheers, Douglas .......
499: Tube DIY Asylum, RE: HV Supply Wish List (0.00)
Posted by PakProtector on 2021-01-10, 17:06:04 (23.125.73.217)
I would not mind being able to go a hair lower in the B+. Ultimately, I'd put this go geetar amp PS duty in SE stuff. Lower-than-HI-Fi numeric loads, solid 100 mA idle per final comes to mind. Peak c .......
500: Tube DIY Asylum, RE: FET-Triode Cascade (0.00)
Posted by PakProtector on 2021-01-10, 16:59:21 (23.125.73.217)
I'd rather invoke Gary Pimm's CCS-loaded pentode. The resistor from plate to ground sets the gain, it has drive outta the wazoo( the mu output ), brilliant PSRR, and a host of smallish signal pentodes .......
Found total of 500 records, Query: , Author: PakProtector in All Forums, Time: 2 sec.