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1: Vintage Asylum, RE: Maybe we need to define "little"? (0.00)
Posted by Russ57 on 2017-06-04, 09:48:16 (162.224.170.76)
Are we talking about two amps that use the same tubes and have the same impedance transformers? Or are we talking about a transformer for EL84's compared to one for 6550's? Very different thing. I'll .......
2: Vintage Asylum, RE: Just curious (0.00)
Posted by Russ57 on 2017-06-03, 19:17:48 (162.224.170.76)
Mark, are you of the opinion that the better vintage transformers are superior to today's offerings? No judgement in my question, just curious. Sadly, IMHO, I would say the engineers who understood au .......
3: Tube DIY Asylum, RE: Should be more than fine (0.00)
Posted by Russ57 on 2017-01-18, 15:28:55 (162.224.170.76)
PP 6V6's (trioded connected and run in strict class A1 operation) will give you about two watts. Those transformers will handle a good bit more and have value. You can get a pair of Silk 10K:8 ohm at .......
4: Tube DIY Asylum, RE: I offer this as regards to causing death (0.00)
Posted by Russ57 on 2017-01-09, 18:25:56 (162.224.170.76)
I was always taught that what causes death is AC hertz close to natural heart beat. AC goes back and forth from positive to zero to negative so one assumes it gives you a chance to get free (if low en .......
5: Vintage Asylum, RE: Indulge (0.00)
Posted by Russ57 on 2016-12-06, 18:52:06 (162.224.170.76)
My experience is many of these guys welcome guys with ears as many of the customers seem to lack them. Be honest with them and see if you agree on things. .......
6: Vintage Asylum, RE: So what did it sound like? (0.00)
Posted by Russ57 on 2016-12-06, 18:01:17 (162.224.170.76)
Once upon a time....I had a friend....who spent hours listening to music at my house while his GF worked out with my GF. Turns out he had a rich audiophile friend. This was rather early on in my audio .......
7: Vintage Asylum, RE: Okay, I'll be the one to be burnt at the stake (0.00)
Posted by Russ57 on 2016-12-04, 18:04:59 (162.224.170.76)
Charles, everything one might call the "vintage tube sound" is nothing more than poor quality/out of tolerance parts.....compounded with worn out tubes, poor circuit design, crappy wiring practices, a .......
8: Vintage Asylum, RE:Mike, I keep warning you about skipping steps (0.00)
Posted by Russ57 on 2016-11-22, 17:05:30 (162.224.170.76)
But will you listen? Hell no! Must be the wolverine in you. .......
9: Vintage Asylum, RE: General tube amp restoration question (0.00)
Posted by Russ57 on 2016-11-19, 10:25:27 (162.224.170.76)
"Let's say you are restoring and upgrading a tube amp. Is your goal to make it sound a clean as possible. By that I mean balanced, no distortion, new parts and a razor sharp square wave." IMHO the ent .......
10: Tube DIY Asylum, Tell us about the caps (0.00)
Posted by Russ57 on 2016-10-25, 12:32:50 (165.214.11.78)
Are they new? What brand and type? They aren't warm are they? Might be worth throwing a high voltage film cap across the first cap bank...1uF 630 volt should do but the bigger the better. Could be you .......
11: Tube DIY Asylum, RE: Does the speaker side of the transformer have the negative lead grounded? (0.00)
Posted by Russ57 on 2016-10-24, 19:27:47 (162.224.170.76)
I'd suggest clip leading RCA shell, negative side of speaker connection, power cord ground, and the ground lead of probe all together. You need them to all be at the same potential. Do all of this wit .......
12: Tube DIY Asylum, The only big difference I see is.... (0.00)
Posted by Russ57 on 2016-10-20, 09:06:29 (165.214.11.77)
The UG1007 is glass passivated (should stand up better in adverse conditions). There are small differences regarding temperature ratings. Mostly they are equal to one another. .......
13: Vintage Asylum, Consumer the winner? (0.00)
Posted by Russ57 on 2016-10-19, 09:27:48 (165.214.11.74)
Charles, take that 9090db I mentioned. Introduced in 1975 with a MSRP of 900 bucks. That is a little over 4 grand today. I don't know about you but I wouldn't pay 4 grand for a receiver even if I coul .......
14: Vintage Asylum, You have to ask yourself what you are after (0.00)
Posted by Russ57 on 2016-10-17, 15:48:56 (162.224.170.76)
I hesitate to ever recommend a reciever. Too much stuff crammed into too small a space. The radio part in these units tends to cause the most problems (in terms of restore) and one has to question how .......
15: Vintage Asylum, RE: Maybe you are buying at the wrong place? (0.00)
Posted by Russ57 on 2016-10-11, 15:57:34 (162.224.170.76)
I show at most a 50% difference....which amounts to less than 50 cents each. Try the big boys like mouser, etc. However if you like the KOA's, then I'd spend the extra money for peace of mind. I'm par .......
16: Tube DIY Asylum, RE: Measure the voltage in/out of the preamp (0.00)
Posted by Russ57 on 2016-09-27, 15:20:14 (162.224.170.76)
Many of todays sources will drive a power amp to clipping without a preamp. So many preamps operate at less than unity gain. This isn't such a smart thing. So lets see what your source and preamp are .......
17: Tube DIY Asylum, Actually (0.00)
Posted by Russ57 on 2016-09-26, 17:17:11 (162.224.170.76)
What you are seeing is 2nd order. The 12at7 family does have different gain at different grid voltages. In a push pull amp this can actually be used to give a reduction in higher order distortion. You .......
18: Tube DIY Asylum, Just curious, would you do a voltage check? (0.00)
Posted by Russ57 on 2016-09-12, 18:14:52 (162.224.170.76)
Andy, IIRC the transformer secondary was 125-0-125. As I understand things you have center tap isolated and are using the full secondary as one winding into a cap input filter. Don't know what you are .......
19: Tube DIY Asylum, Yup, not so (0.00)
Posted by Russ57 on 2016-09-10, 11:21:04 (162.224.170.76)
Try contacting the maker of the transformer. Sometimes you can connect the two secondary windings in series, and do what you want, but at half the current rating. A center tap transformer is designed .......
20: Tube DIY Asylum, RE: Hold on a sec (0.00)
Posted by Russ57 on 2016-09-10, 10:42:56 (162.224.170.76)
You stated the transformer was 125-0-125....meaning it has a center tap. Therefore only the last two pics, full wave, NOT the bridge ones apply. Choke input will get you lower voltage, more current, a .......
21: Tube DIY Asylum, But that is the problem (0.00)
Posted by Russ57 on 2016-09-07, 19:08:24 (162.224.170.76)
Depending on the actual (Country) standard the caps that TK mentioned do not have a rating for VCC. However they do make X7R rated caps (in a different dielectric) that do carry a VCC rating. ::: TOPI .......
22: Tube DIY Asylum, RE: mostly "type 2 caps" (0.00)
Posted by Russ57 on 2016-09-07, 13:16:11 (162.224.170.76)
and is greastest in the small package caps. Not parts we would ever use for audio (IMHO). .......
23: Tube DIY Asylum, voltage coefficients vs. temperature coefficients (0.00)
Posted by Russ57 on 2016-09-06, 20:10:10 (162.224.170.76)
Everybody wants more in a smaller package. That always means a trade off/compromise that one needs to aware of. More than ever you need to know what the designation really means, a complete data sheet .......
24: Vintage Asylum, RE: sort of (0.00)
Posted by Russ57 on 2016-08-22, 11:42:32 (165.214.11.76)
Many are a polyurethane but I wouldn't quite call them varnish. .......
25: Vintage Asylum, RE: a little ohms law helps (0.00)
Posted by Russ57 on 2016-08-21, 10:45:54 (162.224.170.76)
One can see the amps are low enough that small gauge wire is enough for any wattage a speaker would see in a home setting. Try some magnet wire. Might surprise you. I'm of the frame of mind that the i .......
26: Vintage Asylum, RE: Would have liked the long version:) (0.00)
Posted by Russ57 on 2016-08-16, 17:52:50 (162.224.170.76)
One of these days we should talk on the phone. Sometimes a man wants what he wants and that is all there is to it (so go get a 250). I wouldn't advise the model 15. The parts that aren't made anymore .......
27: Vintage Asylum, RE: I have a pair (0.00)
Posted by Russ57 on 2016-08-15, 19:29:32 (162.224.170.76)
Haven't listened to them in quite some time. I remembered them as rather warm sounding. .......
28: Vintage Asylum, RE: Why would you? (0.00)
Posted by Russ57 on 2016-08-05, 18:12:06 (162.224.170.76)
Someone makes a tube. They say 10 uF. Based one something on the web you are willing to risk 15 uF? I don't get it. Increase cap size after the choke. .......
29: Vintage Asylum, RE: If your concern is safety (0.00)
Posted by Russ57 on 2016-08-04, 12:29:34 (165.214.11.75)
Then changing the electrical outlet to a ground fault type is the best possible thing to do. A ground fault outlet does not need a ground to work as intended. They offer a greater level of safety than .......
30: Vintage Asylum, RE:Sounds good (0.00)
Posted by Russ57 on 2016-08-04, 04:34:56 (165.214.11.78)
I have had good results with the "motor run" type caps. ASC brand are easy to come by. .......
31: Tube DIY Asylum, RE: I agree with Eli (0.00)
Posted by Russ57 on 2016-08-04, 04:33:07 (165.214.11.78)
If you desire we could attempt to explain matters. .......
32: Tube DIY Asylum, RE: Without thinking much....how about (0.00)
Posted by Russ57 on 2016-08-01, 17:50:35 (162.224.170.76)
Stacked power supplies (or at least a B-)? Seems to me if a cathode follower was used to drive output tube with its resistor tied to a negative supply....failure of said tube would only make output tu .......
33: Tube DIY Asylum, RE: I also suspect construction (0.00)
Posted by Russ57 on 2016-07-26, 17:02:03 (162.224.170.76)
Most 10uF film caps aren't rolled like a cigar. Could be more of a stacked film design. Anyhow I think it of minor importance compared to other things. I do agree as caps gets bigger it is harder to m .......
34: Tube DIY Asylum, RE: Another boat (0.00)
Posted by Russ57 on 2016-07-25, 17:38:26 (162.224.170.76)
Make the cap part of an oscillator circuit....have cap sets its resonate/determining hertz. Place a conductive plate coupled to a very high impedance amp next to it. One lead of said cap must be groun .......
35: Tube DIY Asylum, RE: Reasonable sounding question but likely missing the boat. (0.00)
Posted by Russ57 on 2016-07-25, 14:59:16 (162.224.170.76)
As TK mentioned it has a lot to do with impedance. The outer foil lead should go to the lower impedance side of the circuit. Consider a coupling cap. Be defintion (i.e. for it to be coupling) the AC v .......
36: Vintage Asylum, RE: Consider Creek (0.00)
Posted by Russ57 on 2016-07-18, 15:11:23 (162.224.170.76)
A British made amp that has always sounded much better than it should for its price. Haven't heard the newer evolution line but the old 4330 was a darn good little amp. Creek's tend to be a little low .......
37: Tube DIY Asylum, RE: Bang for the Buck (0.00)
Posted by Russ57 on 2016-07-10, 15:12:29 (162.224.170.76)
I think cost is always a factor. No doubt you can get a good soilid state amp but can it be done at a cheaper price if wattage isn't a factor? I have a 6V6 triode strapped amp tha6t I consider very go .......
38: Vintage Asylum, RE: Surprised it works (0.00)
Posted by Russ57 on 2016-07-10, 07:09:50 (162.224.170.76)
On most all vintage gear the signal return/ground is attached to the chassis. Many of us have installed a three wire power cord. In that case signal ground and electrical ground are the same. In short .......
39: Tube DIY Asylum, RE: Question for you (0.00)
Posted by Russ57 on 2016-06-30, 14:41:48 (162.224.170.76)
Have always valued your knowledge/posts so a question if I may. Most consumer audio products work with a single ended signal (one hot and one grounded conductor). Given that wouldn't a coax cable be t .......
40: Tube DIY Asylum, RE: But won't he need four SE amps? (0.00)
Posted by Russ57 on 2016-06-25, 11:49:04 (162.224.170.76)
A typical PP amp might have a voltage amp coupled to inverter/splitter coupled to output tubes. One could have the inverter/splitter first if desired (transformer or something else). I guess I am havi .......
41: Tube DIY Asylum, RE: TK is right and it is important (0.00)
Posted by Russ57 on 2016-06-08, 15:52:16 (162.224.170.76)
Fuses are simple and reliable. Switch contacts do get welded/arced together. I do a lot of electrical testing at work. Trust me, you don't want to bet your life on a switch or circuit breaker to actua .......
42: Tube DIY Asylum, RE: They do pose a dilemma (0.00)
Posted by Russ57 on 2016-04-24, 18:15:09 (162.224.170.76)
I do agree that they seem more prone to leakage. That said a great PIO cap can do a wonderful job. Sometimes they are just what is needed to balance the entire audio chain from a tad sterile/clinical .......
43: Tube DIY Asylum, RE: taiwan (nt) (0.00)
Posted by Russ57 on 2016-04-06, 15:46:36 (162.224.170.76)
. .......
44: Tube DIY Asylum, RE: Slow down and prove problem before you do work (0.00)
Posted by Russ57 on 2016-04-05, 14:42:07 (162.224.170.76)
A schematic can save you loads of time. Try and get one and then post it. Car wiring is a different animal. Given that you have individual fuses I wonder if you have a two pole relay. I.E. an individu .......
45: Tube DIY Asylum, RE: What would you consider instead of Tin? (0.00)
Posted by Russ57 on 2016-04-01, 16:52:08 (162.224.170.76)
Easy enough to bash any particular thing. Question is what else could you use? Most any cap will measure better than a transformer yet many say transformers "sound better". What is a guy to do? In cou .......
46: Vintage Asylum, RE: Duh....forgot part#:).....try SS5D (nt) (0.00)
Posted by Russ57 on 2016-03-23, 14:38:20 (162.224.170.76)
. .......
47: Vintage Asylum, RE: Try Omron brand (nt) (0.00)
Posted by Russ57 on 2016-03-22, 15:23:12 (162.224.170.76)
. .......
48: Tube DIY Asylum, RE: Ever thought you might be asking in the wrong place? (0.00)
Posted by Russ57 on 2016-03-04, 17:44:59 (162.224.170.76)
Mostly this is a bunch of Hi-Fi guys. We are interested in amps that create a faithful reproduction of an input signal across a wide bandwith. Guitar amps are designed to price points and for limited .......
49: Tube DIY Asylum, soldering is very easy....unsoldering is a different story:) (0.00)
Posted by Russ57 on 2016-02-27, 15:20:52 (162.224.170.76)
Working on new stuff with normal size connections is a easy. Get a decent quality temperature controlled soldering iron. Hakko or Weller will do. Figure $100-$200 dollar range. 150 watts more or less. .......
50: Tube DIY Asylum, RE: Try Illinois capacitors (0.00)
Posted by Russ57 on 2016-02-11, 15:12:17 (162.224.170.76)
Jim should of had that:) They make a 105C axial rated to 450VDC and the 85C ones are rated to 500VDC. When it comes to aluminum electrolytics (which I try to avoid) I'd much rather have newer designs. .......
51: Tube DIY Asylum, RE: You don't want the atoms (0.00)
Posted by Russ57 on 2016-02-10, 18:37:19 (162.224.170.76)
Only good thing is they are hard to kill. Otherwise overpriced and don't sound very good. Elna, Nichon, Panasonic....all very much better choices (IMHO). .......
52: Vintage Asylum, RE: Congrats (0.00)
Posted by Russ57 on 2016-02-10, 15:53:06 (162.224.170.76)
Did you buy a complete amp kit? Or did you rebuild an older ST70? For a little fun try a 12BH7 (tip Brimar's:) instead of the 12AU7. For a lot of fun check with Bob and see what needs to be done to tr .......
53: Tube DIY Asylum, RE: Just went by your link (0.00)
Posted by Russ57 on 2016-02-06, 20:30:30 (162.224.170.76)
Your link was for a standard aluminum electrolytic cap. Motor run caps are a non-polar film cap. Very different items (IMHO). For a power supply in an amp I'd look at the ASC X386S for a nice sounding .......
54: Tube DIY Asylum, RE: Those aren't motor run caps (0.00)
Posted by Russ57 on 2016-02-04, 18:40:04 (162.224.170.76)
Motor run type caps are usually rated 20+ amp range. These days I think it is better to call them "oil filled metalized polypropylene" caps. Used to be we were talking about AC rated caps used with mo .......
55: Tube DIY Asylum, RE: I would give them a try (0.00)
Posted by Russ57 on 2016-01-07, 15:16:48 (162.224.170.76)
I like poly in oil motor run caps. Been using them for decades. Was always a fan of certain series of the GE caps. Now they are made in "another country". Epocos is a European cap. Much rather gamble .......
56: Vintage Asylum, RE: That is why everyone needs a vinyl source (0.00)
Posted by Russ57 on 2015-12-22, 17:10:18 (162.224.170.76)
Had a friend who resisted for so long it was ridiculous. Had a very high end but older CD system. Between a turntable and an Oscope he really upped his game. Nice thing is so much of the music we grew .......
57: Tube DIY Asylum, RE: Nice post (0.00)
Posted by Russ57 on 2015-12-22, 16:37:20 (162.224.170.76)
Most would argue if you said a GFCI doesn't need a ground wire to function.....or if one said current flowing through a ground wire to ground rod(s) (alone) would (probably) never trip a circuit break .......
58: Tube DIY Asylum, RE: Good questions (0.00)
Posted by Russ57 on 2015-12-22, 16:18:17 (162.224.170.76)
Transformers provide what we call "galvanic isolation". This is a fancy way of saying the current loops are isolated provided the ground paths aren't common. In essence...if we take a power transforme .......
59: Tube DIY Asylum, RE: Define "circuit ground" (0.00)
Posted by Russ57 on 2015-12-21, 16:35:35 (162.224.170.76)
Every circuit must return to it's source. In most tube amps that is through power supply caps and/or center tap of power transformer. Those power supply caps are attempting to discharge rather high vo .......
60: Vintage Asylum, RE: There could be a misunderstanding (0.00)
Posted by Russ57 on 2015-12-21, 15:46:17 (162.224.170.76)
I agree that old capacitors are not going to be magically restored by "reforming". However brand new capacitors that have set on the shelf for 2 to 3 years require it. This is standard knowledge on pr .......
61: Vintage Asylum, RE: To try and get closer to your question (0.00)
Posted by Russ57 on 2015-12-16, 20:10:24 (162.224.170.76)
First off, there is no doubt there have been advances in caps over the years. Also no doubt that all amps are built to a price point. So I have no problem buying an improvment in your amp from some ca .......
62: Vintage Asylum, RE: I'm with Andy......"tube sound" equals something wrong (0.00)
Posted by Russ57 on 2015-12-16, 18:25:27 (162.224.170.76)
It is a shame so many never have the chance to hear anything beyond certain type/class of tube equipment. Nine pin voltage gain tubes cap coupled to pentodes.....hmmmm....okay if your goal is maximum .......
63: Vintage Asylum, RE: My 2 cents (0.00)
Posted by Russ57 on 2015-12-07, 17:38:02 (162.224.170.76)
I'd look at Creek. But you will have to settle for integrated amp. .......
64: Tube DIY Asylum, RE: its it ok to use 2 series resistors as plate load (0.00)
Posted by Russ57 on 2015-10-12, 16:04:41 (162.224.170.76)
In general, yes. I'd suggest both of your resistors need to have higher wattage ratings. I like a 4 times rating. Remember you are calculating from static/bias conditions. .......
65: Vintage Asylum, RE: A few things to consider (0.00)
Posted by Russ57 on 2015-09-19, 18:39:27 (162.224.170.76)
Consider what we need a preamp to do. 1) It picks between sources. In the past we might have had a phono, tape deck, tuner, etc. So what do you have? If only a CD/DVD why do you need a selector switch .......
66: Vintage Asylum, RE: A few things to consider (0.00)
Posted by Russ57 on 2015-09-17, 15:52:34 (162.224.170.76)
A higher than needed wattage resistor might offer "safety factor" for the resistor.....but it offers less protetion for more important items like tubes. It is like using a 30 amp circuit breaker on 20 .......
67: Tube DIY Asylum, RE: Don't misunderstand (0.00)
Posted by Russ57 on 2015-09-02, 15:50:24 (162.224.170.76)
Provided the input to the meter is greater than 50 millivolt it will measure it within a tenth of a millivolt. Kudos to them for making this clear. Go look at the specs for their meters that cost WAY .......
68: Tube DIY Asylum, RE: One you might want to look at (0.00)
Posted by Russ57 on 2015-08-29, 10:50:52 (162.224.170.76)
I'm not one for snake oil either. Take a look at Eupen power cords. I think you will agree how it "might" make a difference in some cases. If only in the sense that noise from other crap might be kept .......
69: Tube DIY Asylum, RE: At least they are honest (0.00)
Posted by Russ57 on 2015-08-27, 15:50:51 (162.224.170.76)
All meters have limitations. Most don't make you aware of them. People assume because they see a number they can take it to the bank. Even understanding supposed accuracy can be difficult as most are .......
70: Vintage Asylum, RE: end bells are one think....lams quite another (0.00)
Posted by Russ57 on 2015-08-25, 17:49:12 (162.224.170.76)
If you can remove end bells/covers then sandblast and coat/electroplate as desired. In no case do you want to do anything aggressive to the lams. Just spray paint over the rust on them (IMHO). ::: TOP .......
71: Tube DIY Asylum, RE: I wouldn't (0.00)
Posted by Russ57 on 2015-08-15, 16:10:59 (162.224.170.76)
Can't think of a more deserving place for a quality resistor. Also a good place for picking a resistor to give the overall sound you want. I'd be thinking good carbon film if amp was sterile/cold and .......
72: Tube DIY Asylum, RE: Why? (0.00)
Posted by Russ57 on 2015-07-11, 19:15:49 (162.224.170.76)
You could call it a AC coupled long-tailed Pair....or cathode/self biased long-tailed pair. Other names are possible. Very common in guitar amps. .......
73: Tube DIY Asylum, RE: I might suggest (0.00)
Posted by Russ57 on 2015-07-08, 16:32:33 (162.224.170.76)
Triode strap EL84's and ditch golbal feedback from secondary of OPT. If there is still a problem many of the usual suspects have been eliminated. In my limited experience mistakes on the OPT wiring re .......
74: Tube DIY Asylum, RE: Why? (0.00)
Posted by Russ57 on 2015-07-08, 16:28:07 (162.224.170.76)
You have a pair of ECC83 drawing current through a series connection of 1K and 22K resistors. Figure each half does 0.001 amps. So you have 0.002 amps going through a 22K resistor. The grids are refer .......
75: Vintage Asylum, RE: When to just buy newer (0.00)
Posted by Russ57 on 2015-06-06, 10:19:51 (162.224.170.76)
I think you sell yourself short. These days instructions on how to restore gear is easy to come by. You have places like this to help explain and advise. Restoring gear is where most of us start and t .......
76: Tube DIY Asylum, RE: Why you can't get a good answer (0.00)
Posted by Russ57 on 2015-05-22, 15:24:26 (162.224.170.76)
A given amp has a limit to how many watts it can put out. Depending on the amp it may have the ability to briefly handle a larger "peak" wattage....or it may not. SET amps often don't have much extra .......
77: Tube DIY Asylum, RE: I'll offer something else to consider (0.00)
Posted by Russ57 on 2015-04-19, 19:24:24 (162.224.170.76)
My experience is more in commercial/industrial electrical distribution. I see a fair amount of failure due to surface contamination. Carbon arcing on contactors on boilers. Arcing across disconnects u .......
78: Tube DIY Asylum, RE: What makes you think you need a solution? (0.00)
Posted by Russ57 on 2015-03-23, 16:18:57 (162.224.170.76)
You are talking around 5.86% difference. Chances are your tubes, resistors, capacitors, etc. (all taken together) don't have a tighter tolerance (not to mention your power provider). If you are experi .......
79: Tube DIY Asylum, RE: Low Powered Guitar Amp Head (0.00)
Posted by Russ57 on 2015-03-02, 15:00:53 (162.224.170.76)
Never built such a thing....but I have to vote for 6V6 too. I have come to develop a love affair, albeit triode wired. .......
80: Tube DIY Asylum, RE: choke input bias supply (0.00)
Posted by Russ57 on 2015-03-02, 14:38:04 (162.224.170.76)
IMHO the most important feature would be for the negative bias supply to have its own winding. I would like to see a full wave rectifier. I would like to see generous size capacitors. Mostly I want a .......
81: Vintage Asylum, RE: Tell us about the turntable (0.00)
Posted by Russ57 on 2015-03-01, 19:12:33 (162.224.170.76)
It could be something as simple as a supension adjutment on the turntable.....but then that would depend of if your turntable has any such adjustments. I'm inclined to think you could be looking in th .......
82: Vintage Asylum, RE: Here you go (0.00)
Posted by Russ57 on 2015-02-28, 19:53:23 (162.224.170.76)
Try this link. A very good collection that I am glad to see is still around. Crowhurst is a good place to start. I would also grab any old ARRL handbooks I find at second hand stores. http://www.tubeb .......
83: Vintage Asylum, RE: a question about what exactly was the problem (0.00)
Posted by Russ57 on 2015-02-28, 15:52:54 (162.224.170.76)
I see some mention of runaway voltages, that the 4uF hunt capacitors were bad, maybe that a couple of EL34's were found to be the problem in the end. Hard to make heads/tails of what the original prob .......
84: Vintage Asylum, RE: I'll try (0.00)
Posted by Russ57 on 2015-02-28, 11:14:23 (162.224.170.76)
It gets hard to write something reasonably short without knowing anything of your knowledge. A book or two might be in order. You can email me if you'd like. The power supply transformer takes your wa .......
85: Vintage Asylum, RE: Sorry but I smell BS (0.00)
Posted by Russ57 on 2015-02-27, 14:59:52 (162.224.170.76)
According to schematic and parts list I found, that 4uF cap is between a GZ34 and choke in the power supply. As long as it isn't plain old bad it wouldn't effect balance in any way. Just check to see .......
86: Vintage Asylum, RE: And know you understand the "personal" comment (0.00)
Posted by Russ57 on 2015-02-19, 19:03:16 (162.224.170.76)
1.Wouldn't you want to use a choke with solid state rectifier also? Yes, I would. I just find I like the sound of tube rectifiers. Damper diodes are some of the best IMHO. 2.What about pentode wired i .......
87: Vintage Asylum, So airtime...ping:) (0.00)
Posted by Russ57 on 2015-02-19, 14:34:47 (162.224.170.76)
How is the CJ preamp sounding? .......
88: Vintage Asylum, RE: And know you understand the "personal" comment (0.00)
Posted by Russ57 on 2015-02-19, 14:33:29 (162.224.170.76)
IMHO, all things equal: 1) I'd rather have a choke input power supply with a tube rectifier. 2) I'd rather have a LTP splitter, then a split-load, and lastly a paraphase. If you can't tell from lookin .......
89: Vintage Asylum, RE: Post favorite vintage EL84 amps and why (0.00)
Posted by Russ57 on 2015-02-18, 16:16:43 (162.224.170.76)
The whys are too personal to get into. I'd probably go Acrosound 20/20 first, maybe Leak 20 or pilot 232 second, say Fisher sa-100 third, then the eico's (think they were hf14's and 30's?). EL-84's ar .......
90: Tube DIY Asylum, RE: I reached same conclusion (0.00)
Posted by Russ57 on 2015-02-16, 13:37:12 (165.214.11.78)
Ended up liking electronic crossover at 125-200 hertz depending on drivers used.....and passive between mid-range and tweeter. Always wondered if I had a fancy digital one with recording mike hooked u .......
91: Vintage Asylum, RE: A few more words (0.00)
Posted by Russ57 on 2015-02-12, 16:09:06 (162.224.170.76)
After nearly fifty years of repairing things I could write several textbooks. Again feel free to email if there is something in particular you would like explained. I'm going to tell you that troubles .......
92: Vintage Asylum, RE: FWIW (0.00)
Posted by Russ57 on 2015-02-12, 10:55:19 (165.214.11.74)
I'm a maintenance man at a hospital. My dad was a mechanic. Fixing things is what I do. Feel free to contact me if I can be of assistance on your home repairs. There are certain items you might wish t .......
93: Tube DIY Asylum, RE: fair enough (0.00)
Posted by Russ57 on 2015-02-11, 19:35:47 (162.224.170.76)
FWIW, ESR goes down as temp, hertz, and cap uF goes up. Certain tube diodes might require such a small input cap that ESR could be 2 ohms or more, but most would be way under that amount. One would ho .......
94: Vintage Asylum, RE: Reliable, surely you jest (0.00)
Posted by Russ57 on 2015-02-11, 16:46:23 (162.224.170.76)
Those TV's back then may have needed new tubes and some tuner cleaner now and then, but they lasted for decades. I can promise you nothing made today will last that long. Today stuff works fine right .......
95: Tube DIY Asylum, RE: question (0.00)
Posted by Russ57 on 2015-02-11, 14:04:46 (162.224.170.76)
Jeff, do you think a given electrolytic capacitor's esr would be higher at 10khz or 120 hertz? Do you think it would increase as the capacitor uF went up? .......
96: Tube DIY Asylum, RE: psud2 c1 esr (0.00)
Posted by Russ57 on 2015-02-10, 17:46:22 (162.224.170.76)
Probably get flamed here. I think folks get too worked up about "transient" behavior in these sims. After a brief time there isn't that much difference in average current regardless of capacitor size. .......
97: Tube DIY Asylum, RE: Yes, that is what I am telling you (0.00)
Posted by Russ57 on 2015-02-06, 15:39:46 (162.224.170.76)
All things equal, a larger cap has lower ESR. Now that is not the same as saying a big electrolytic has lower ESR than a poly cap. Hearing a difference, calling it an improvemt, and stating the reason .......
98: Tube DIY Asylum, RE: And wrong on many levels (0.00)
Posted by Russ57 on 2015-02-06, 10:48:11 (165.214.11.73)
Hope they listen to you. They sure seem to be drinking Mike's kool aid. Doesn't take long to note ESR of electrolytic caps goes down as hertz and temperature go up. ESR also goes down as cap size incr .......
99: Tube DIY Asylum, RE: One question...or problem I'm having (0.00)
Posted by Russ57 on 2015-02-03, 18:24:00 (162.224.170.76)
Aside from what any simulation shows....because who knows who made/programmed them, etc. How can any increase in source inductance, and therefore increase in conduction angle, equate to higher DC volt .......
100: Vintage Asylum, RE:Actually very little has changed (0.00)
Posted by Russ57 on 2015-02-03, 11:53:33 (165.214.11.82)
By and large PCM still rules as it has since the beginning. DSD is now in the picture. It is basically the old SCAD standard. DVD audio is basically dead. There are some important differences in how t .......
101: Vintage Asylum, RE: I'd say put your money in a DAC (0.00)
Posted by Russ57 on 2015-02-02, 16:03:07 (162.224.170.76)
USB based solutions allow the computer to be the transport and offer a lot of positives. .......
102: Tube DIY Asylum, RE: Is it possible? (0.00)
Posted by Russ57 on 2015-02-02, 15:26:53 (162.224.170.76)
A thinking man would deduce that we like a sagging power supply. That it, for us, equates to a more real/musical sound. I'll go first. I'll admit that I often pick a tube rectifier that has more volta .......
103: Tube DIY Asylum, RE: Meets my idea of beautiful construction (0.00)
Posted by Russ57 on 2015-02-02, 13:21:18 (162.224.170.76)
Always liked it when my fulgy stuff sounded better than some guys fancy store bought item. In most cases fabulous looks equals high maintenance:) .......
104: Tube DIY Asylum, RE: One more thing.....why do we seem to care the least about the worst parts? (0.00)
Posted by Russ57 on 2015-02-02, 13:13:09 (162.224.170.76)
Compared to even a bad amp most speakers are....well....broken (and that is being kind). Never had the money for electrostatic's. Best I could do was active crossover and limiting range to where the d .......
105: Tube DIY Asylum, Passive devices are harder to hear (0.00)
Posted by Russ57 on 2015-02-02, 11:49:12 (165.214.11.76)
Most anyone will agree that if you use a part of low enough quality it degrades the sound. So if you think using a coat hanger for an interconnect harms matters then you are acknowledging that a high .......
106: Tube DIY Asylum, RE: Me thinks you sell my friend a little short (0.00)
Posted by Russ57 on 2015-01-30, 17:02:01 (162.224.170.76)
At one time I might have agreed with some of your conclusions/observations. Rest assured what he does now is well tested....by tektronix, fluke, and aligent plus his golden ears. He has learned it has .......
107: Tube DIY Asylum, RE: Perfect time for me to jump in here:) (0.00)
Posted by Russ57 on 2015-01-30, 15:30:45 (162.224.170.76)
A little history. Wheezer and I know each other. He was into audio before I was. I'm a maintenance guy at a hospital and consider electrical skills my strong suit. I get to see a lot of fancy stuff. W .......
108: Vintage Asylum, RE: Dynaco A25/A25XL (0.00)
Posted by Russ57 on 2015-01-30, 00:31:27 (165.214.11.68)
Last time I checked you could still buy the seas woofer. IIRC the Morel MDT20??? tweeter was a near perfect replacment. .......
109: Tube DIY Asylum, RE:The only thing you can say for sure about science is.... (0.00)
Posted by Russ57 on 2015-01-29, 22:57:19 (165.214.11.68)
What is true today probably won't be 100% of the total truth tomorrow. I could just imagine having a talk with some of the great minds from the past and trying to convine them of subatomic particles w .......
110: Tube DIY Asylum, RE: That part that bothers me more... (0.00)
Posted by Russ57 on 2015-01-29, 15:52:14 (162.224.170.76)
Hery had been through wars with Jute in the past so he saw something coming that I didn't. He was right. Regardless I can live with Jeff and his power supply idea. Two thgings really bother me though. .......
111: Vintage Asylum, RE: You picked the ugly one! (0.00)
Posted by Russ57 on 2015-01-27, 15:32:15 (162.224.170.76)
Not aware of any modern mainstream commerical amps using CCS's. Can't say I keep up anymore honesty. Bottlehead has long been using them though. The EL34 is pretty easy to drive as a pentode, little m .......
112: Vintage Asylum, RE: Why integrated?....or must it be integrated? (0.00)
Posted by Russ57 on 2015-01-26, 15:48:49 (162.224.170.76)
I could write a fricking essay and started to. At the end of the day it isn't about brand name but circuit design and tube choice. I'm going to tell you there is no shortcut and you need to educate yo .......
113: Tube DIY Asylum, RE: Jeff, of all the people...... (0.00)
Posted by Russ57 on 2015-01-25, 19:32:07 (162.224.170.76)
I would have understood if you objected. After all there are speakers, like Altecs (and others), that don't need threee drivers to get the job done. One might argue they aren't 20-20khz but I'll be th .......
114: Vintage Asylum, RE: Fair enough (0.00)
Posted by Russ57 on 2015-01-25, 19:24:42 (162.224.170.76)
I did mention the 4PL1 would likely require a bit more work. There is long thread on diyaudio about one they have developed. The problems are solveable and the results are worth the effort. Still I ca .......
115: Tube DIY Asylum, RE: Dirty truth about many speakers (0.00)
Posted by Russ57 on 2015-01-24, 22:11:24 (162.224.170.76)
Disclaimer, I don't know enough to make this post but I'll try and point you in the right direction. Take a look around at places that sell all the big name drivers (not finished speakers but raw driv .......
116: Vintage Asylum, RE: wirewound resistors question... (0.00)
Posted by Russ57 on 2015-01-24, 20:44:38 (162.224.170.76)
The 12 watt mills can be had up to 100K. Most tubes that use high resistance are running very low currents, like 12AX7's. Aside from suggesting avoiding such tubes:).....just use a decent metal or car .......
117: Tube DIY Asylum, RE: I don't see that cap listed on their web site (0.00)
Posted by Russ57 on 2015-01-23, 13:50:54 (162.224.170.76)
I doubt you will have a problem but it mostly depends on how long the over voltage lasts. If for a fraction of a second...or one full second...pretty much sure it will be no problem. If several second .......
118: Tube DIY Asylum, RE: Ever get to scrounge any musical amp speakers? (0.00)
Posted by Russ57 on 2015-01-23, 08:37:46 (165.214.11.77)
Most of them are wide range and efficent. Could make the start of a good set of speakers. We all know a 6v6 guitar amp can play pretty loud. .......
119: Tube DIY Asylum, RE: One hard lesson, speakers are everything (0.00)
Posted by Russ57 on 2015-01-22, 17:23:43 (162.224.170.76)
Tube watts are precious. To get more forces you into pentode, ultralinear, or tetrode mode. Doing that forces you into feedback. All of that forces you into a much greater understanding of electonics .......
120: Tube DIY Asylum, RE: how much power do you need? (0.00)
Posted by Russ57 on 2015-01-22, 14:57:52 (162.224.170.76)
One of my favorite amps is a 6V6 in triode mode. 6CG7 voltage amp direct coupled to a 6cg7 split-load invertor. No feedback, B+ around 300 volts, 10K output transformers. Very simple and straight forw .......
121: Vintage Asylum, RE: The bottlehead smash in in that price range (0.00)
Posted by Russ57 on 2015-01-22, 09:08:39 (165.214.11.72)
The only "stability" issue of I know of with the 4PL1 tube is it is prone to micro-phonics. Think tube dampers or resilient mounting. It also requires a clean power supply. Bottlehead's kit should add .......
122: Vintage Asylum, Ping airtime (0.00)
Posted by Russ57 on 2015-01-21, 16:01:04 (162.224.170.76)
Review on a 4PL1 preamp like I suggested below. Don't miss out on a good thing:) Feel free to email if you have questions. http://www.6moons.com/audioreviews2/supratek/1.html .......
123: Vintage Asylum, RE: Mike, no idea what "goop" is but I can say for sure that..... (0.00)
Posted by Russ57 on 2015-01-21, 15:26:10 (162.224.170.76)
standard silicone caulk is corrosive. No need to take my word for it. A simple web search will provide all the answers needed. They do make acetic free silicone and that is fine. Did find this in a MS .......
124: Vintage Asylum, RE: Caution (0.00)
Posted by Russ57 on 2015-01-21, 14:07:30 (162.224.170.76)
Standard silicone is corrosive. Make sure to use an electronics grade like Wheezer posted. The smell with associate with silicone is acetic acid. .......
125: Vintage Asylum, RE: No this one (0.00)
Posted by Russ57 on 2015-01-16, 16:33:02 (162.224.170.76)
I was suggesting the beepre, built around the 300b tube. http://bottlehead.com/?product=beepre-300b-preamplifier-kit For less $$$, the smash, built around the 4P1L tube, might have more sonic potentia .......
126: Vintage Asylum, RE: Dynaco PAS 3 kit with modern amp question (0.00)
Posted by Russ57 on 2015-01-15, 16:37:24 (162.224.170.76)
Charles, why not try something different? Something that may turn your world upside down. Bottlehead has always offered good value. Their current top line preamp is in a different leauge. See what dir .......
127: Tube DIY Asylum, RE: Perhaps the reason is.... (0.00)
Posted by Russ57 on 2015-01-15, 10:37:12 (165.214.11.68)
Mike does work for others on vintage gear. Those owners often grow to think the sound of old out of tolerance parts is that "tube magic sound". Repair their amp and they may feel it has been ruined. S .......
128: Tube DIY Asylum, RE: I would have agreed with your first post Jim (0.00)
Posted by Russ57 on 2015-01-05, 15:43:43 (162.224.170.76)
Really depends on the transformer. Today many parts are made to compete on price. On the other hand; sometimes it pays to make one part, speced for the most rigourous service, and re-label as needed. .......
129: Tube DIY Asylum, RE: The other half...inductors (0.00)
Posted by Russ57 on 2014-12-30, 15:20:24 (162.224.170.76)
Caps and inductors are both energy storage devices. For an overly easy concept I like to say: caps supply an infinite amount of current to keep voltage a constant....and inductors supply an infinite a .......
130: Tube DIY Asylum, RE: I think you have to look at it in a different light (0.00)
Posted by Russ57 on 2014-12-30, 14:22:00 (162.224.170.76)
I would argue that the cap will always be charged to 1.4. If too small it will simply be charged to that value for too short of a time period to be measured by a multimeter. So now we have to ask how .......
131: Tube DIY Asylum, RE: What tubes are you using (0.00)
Posted by Russ57 on 2014-12-24, 09:31:50 (165.214.11.74)
Good tubes are often the most cost effective upgrade. Hard to advise much without knowing what parts were used. The power supply diodes might be a good place to target. The feedback cap and resistor ( .......
132: Tube DIY Asylum, RE: Beat me to it (0.00)
Posted by Russ57 on 2014-12-24, 08:51:06 (165.214.11.74)
Even if he wants to keep the bypass caps he could make them half the size (uF) and keep the same roll off point (IIRC). He just needs to remember to keep both resistors but only one cap. .......
133: Vintage Asylum, RE: My 22222 cents (0.00)
Posted by Russ57 on 2014-12-11, 18:12:27 (162.224.170.76)
IMHO tube gear is all about having something you can "fuss with". From simple upkeep like setting the bias, to rolling different tubes, to trying different capacitors and resistors. It is part of the .......
134: Tube DIY Asylum, RE: Just thinking out loud here (0.00)
Posted by Russ57 on 2014-11-26, 10:13:02 (165.214.11.78)
From what I gather the front panel is thick, like 1/2" but everything else is much thinner (like what, 1/4" or 16 gauge?). Could you do something like cut a female dovetail in the thick part and epoxy .......
135: Tube DIY Asylum, RE: A few things to consider (0.00)
Posted by Russ57 on 2014-11-24, 13:12:02 (165.214.11.75)
Oh trust me....240 single phase is the least you will get away with....and think stove receptacle:) For 1/2" you'd likely be well into 3 phase 480 volt range. Aluminum is a huge heat sink and takes a .......
136: Tube DIY Asylum, RE: A few things to consider (0.00)
Posted by Russ57 on 2014-11-24, 07:28:00 (165.214.11.75)
First, you would be talking about a very powerful machine in order to weld 1/2". I think it will be out of your budget and beyond the limits of your electrical supply (assuming we are talking about wo .......
137: Tube DIY Asylum, RE: Why bother when the answer is already known? (0.00)
Posted by Russ57 on 2014-11-17, 15:00:42 (162.224.170.76)
Far and away....bulk metal foil is your best bet....assuming it is noise you are concerned with. The next best is wirewound but now inductance becomes a major issue (perhaps). Now that doesn't mean th .......
138: Tube DIY Asylum, RE: 6V6 triode strapped fits the bill (0.00)
Posted by Russ57 on 2014-10-31, 09:53:55 (165.214.11.73)
New production tubes aren't bad and lots of good old ones. Love the way mine sounds. Easy to drive too! .......
139: Vintage Asylum, RE: Shouldn't be surprised....and the value of search function (0.00)
Posted by Russ57 on 2014-10-17, 17:51:45 (162.224.170.76)
Over the years we have been blessed with some very good people posting. I always appreciated hearing joe rosen rant and rave. He once told me that Sherwood tube gear had a sound that would appeal to S .......
140: Tube DIY Asylum, RE: Didn't want to put words in your mouth (0.00)
Posted by Russ57 on 2014-10-04, 15:37:16 (162.224.170.76)
....something it seems I'm guilty of at times. You are a good man and I hope nickelcore understands you have his best interests at heart. Some people get emotionally invested in their ideas and don't .......
141: Tube DIY Asylum, RE: The elephant in the room (0.00)
Posted by Russ57 on 2014-10-04, 14:58:15 (162.224.170.76)
You as using type 83 tubes, not solid state diodes. Therefore you can't take (full) advantage of ultra low DCR and a huge first cap. I'm sure Tre wouldn't be saying as much if you were using different .......
142: Tube DIY Asylum, RE: You sell yourself short (0.00)
Posted by Russ57 on 2014-10-04, 08:56:49 (162.224.170.76)
If you can understand how a cap forms a filter you can certainly learn how a resistor effects a tube. A little ohm's law, a little reading on load lines, etc. Pete Millet, at one time, had a lot of bo .......
143: Tube DIY Asylum, RE: I think this is a great idea (0.00)
Posted by Russ57 on 2014-10-03, 15:59:31 (162.224.170.76)
It is your preamp and if learning is more important than resale value (and it should be IMHO) go for it. My 2 cents on what you say and how to move forward: 1) Try to change one thing at a time in ord .......
144: Tube DIY Asylum, RE: Value of current inrush resistor (0.00)
Posted by Russ57 on 2014-10-01, 18:30:48 (162.224.170.76)
A diode shuts off when the voltage is higher on its output side than its input side (you also have to consider the diodes own voltage drop, about 15 for yours). With a cap input filter your voltage on .......
145: Tube DIY Asylum, RE: The way I see it (0.00)
Posted by Russ57 on 2014-09-25, 18:30:35 (162.224.170.76)
There will always be a certain crowd that will "buy" what someone posts on line but will reject what others say on line. Cleet buys what Hagerman says but rejects what others here say. Never mind the .......
146: Tube DIY Asylum, RE: Look at the whole picture. (0.00)
Posted by Russ57 on 2014-09-21, 20:07:06 (162.224.170.76)
The power supply needs to provide ripple reduction, energy storage, and low impedance return at audio hertz. The ripple reduction is best handled by a combination of caps and chokes. Chokes store ener .......
147: Tube DIY Asylum, RE: What do you need? (0.00)
Posted by Russ57 on 2014-09-21, 09:52:08 (162.224.170.76)
There is a better selection of high voltage caps these days because of things like variable speed drives for motors. The CDE brand 947C series caps are rated at and above the 1200 VDC you mentioned. T .......
148: Tube DIY Asylum, RE: valid part and link to data sheet (0.00)
Posted by Russ57 on 2014-09-20, 19:04:49 (162.224.170.76)
http://www.hitachiaic.com/docs/products/HCGWA_Series_Screw_Terminal_Aluminum_Capacitors.pdf .......
149: Tube DIY Asylum, RE: To make matters more damning (0.00)
Posted by Russ57 on 2014-09-20, 17:08:08 (162.224.170.76)
Hitachi doesn't make a "FA" series cap. They make FA5 and FA6 IIRC. Cap is clearly a fake. The non-polar, polypro, motor run stuff is enough of a clue. .......
150: Tube DIY Asylum, RE: use care (0.00)
Posted by Russ57 on 2014-09-19, 16:45:57 (162.224.170.76)
First off, why is a non polar cap marked with a positive terminal. Also: http://www.hitachiaic.com/news/Alert .......
151: Tube DIY Asylum, RE: Because (0.00)
Posted by Russ57 on 2014-09-05, 18:16:54 (98.77.240.63)
The screw, if conductive, can't touch one of, the heatsink or to220 tab. So...for a tapped hole..you want a bushing that the screw goes thru....that fits through the hole in the to220 tab....and exten .......
152: Tube DIY Asylum, RE: Tapped hole huh? (0.00)
Posted by Russ57 on 2014-09-05, 16:01:09 (98.77.240.63)
I'm thinking that could be a problem. Most mounting kits are made for through hole. .......
153: Tube DIY Asylum, RE: I have to say (0.00)
Posted by Russ57 on 2014-09-02, 14:47:52 (184.33.98.234)
Once upon a time I had a girlfriend who taught aerobics out of our house. One lady (client) used to bring her boyfriend with her (she didn't drive) and we listened to my stereo drank/smoked/BS'ed. One .......
154: Tube DIY Asylum, RE: IMHO (0.00)
Posted by Russ57 on 2014-08-20, 11:29:10 (165.214.11.77)
It has a lot to do with safety. 1) If I have you build something that I know darn well is going to blow up in your face I think that is a "safety" issuse. 2) If I have you build something that I know .......
155: Tube DIY Asylum, RE:Are you willing to build it first? (0.00)
Posted by Russ57 on 2014-08-20, 10:04:07 (165.214.11.70)
If you are going to suggest something it seems only right that you have first hand positive experience with it. So build the darn thing:) Who knows, maybe it will be prone to oscillations or something .......
156: Tube DIY Asylum, RE: I think it starts with this (0.00)
Posted by Russ57 on 2014-08-19, 18:58:38 (98.77.240.226)
1) It is much less dangerous to build it right the first time. The real danger is in trouble shooting, especially if it must be done with power on. This is where you can help Jeff. Make sure he has a .......
157: Tube DIY Asylum, RE: Consider this (0.00)
Posted by Russ57 on 2014-08-19, 09:33:26 (165.214.11.75)
Using a higher voltage cap (than needed) results in longer life. No problems at all other than increased size and cost. I like to avoid series caps when I can. Not long ago it was hard to find high vo .......
158: Tube DIY Asylum, RE: Consider this (0.00)
Posted by Russ57 on 2014-08-19, 04:28:28 (165.214.11.74)
The two caps in series, 220uF and 47uF, add up to 38.73uF. What I'd think you would want is a cap within the rating of the rectifier tube and rated above the no load voltage on the transformer. You co .......
159: Amp/Preamp Asylum, RE: What? (0.00)
Posted by Russ57 on 2014-08-15, 19:18:03 (184.33.100.20)
Power factor can range from negative 1 to positive 1. It is the ratio of real and apparent power. A purely resistive load would have a power factor of 1. A power factor of -1 would be something that i .......
160: Amp/Preamp Asylum, RE: What? (0.00)
Posted by Russ57 on 2014-08-15, 18:10:30 (184.33.100.20)
if you have a Non-Resistive load (PF Volt amps goes down. Current is used more efficently. That is what the power company cares about and why they charge for poor power factor. .......
161: Amp/Preamp Asylum, RE: What? (0.00)
Posted by Russ57 on 2014-08-15, 15:35:35 (184.33.100.20)
I'll deal with the second part first. As I understand it, YOUR formula is wrong. Watts = VA * PF Watts does equal volt amps times power factor. That is a fact. PF is always The absolute value of power .......
162: Amp/Preamp Asylum, RE: Your question is flawed (0.00)
Posted by Russ57 on 2014-08-15, 10:35:34 (165.214.11.72)
First off, watts = power factor × amps × volts. So when you say 1 amp at 120 volts equals 120 watts.....that would only be true with a power factor of 1. If you had something that drew 1 amp at 120 vo .......
163: Tube DIY Asylum, RE: Quite the opposite (0.00)
Posted by Russ57 on 2014-08-07, 12:20:43 (165.214.11.73)
While your transformer might not be "enough larger" to matter.... larger transformers are more efficent. Really big ones (think electric company) are up around 99%. Little bitty (few volt-amps) might .......
164: Tube DIY Asylum, RE: -33?????? (0.00)
Posted by Russ57 on 2014-08-01, 14:46:28 (98.77.241.136)
If true that is biased really cold. On course it would depend on plate to cathode voltage. But given the 400 VDC max plate voltage rating it seems very cold to me. Perhaps they were going for maximum .......
165: Tube DIY Asylum, RE: Measure your voltage on pin 5 (0.00)
Posted by Russ57 on 2014-07-31, 08:38:55 (165.214.11.73)
Verify adjustment pot changes pin 5 voltage. Suspect you will see a range from negative high teens to mid twenties. I assume you read my post below? .......
166: Tube DIY Asylum, RE: bias is set rather differently (0.00)
Posted by Russ57 on 2014-07-29, 20:58:30 (98.77.242.77)
Most amps set the output tubes bias point through one of two methods. A) There is a resistor from cathode to ground. It may be shared between both tubes in one channel, or even all four tubes. Or ther .......
167: Tube DIY Asylum, Try this (0.00)
Posted by Russ57 on 2014-07-29, 08:33:09 (165.214.11.72)
http://www.recordcrate.net/diy/ClassRoom/ga400ac.pdf It should help a lot. In push pull as one tube's current goes down (and so plate voltage goes up) the other tube is doing the opposite. It is only .......
168: Tube DIY Asylum, RE: I'll add a couple of things (0.00)
Posted by Russ57 on 2014-07-17, 10:01:41 (184.33.95.193)
The power factor of the load has a bearig on voltage regulation. It is something that is often overlooked. The smaller the VA, the worse the regulation. You can pay for better regulation but the trasf .......
169: Tube DIY Asylum, Having been down this path (0.00)
Posted by Russ57 on 2014-07-05, 21:27:51 (184.33.95.37)
The problem isn't the signal your amp has to handle.....it is the signal your speaker (individual drivers) have to handle. Let that sink in real good and hard. The simple solution you are after leaves .......
170: Tube DIY Asylum, RE: No, not at all (0.00)
Posted by Russ57 on 2014-06-20, 11:31:00 (165.214.11.69)
Fisher used very nice parts. Tubes were Tele's and Mullards. Coupling (film type) caps and resistors were often top grade German parts. Never needed to replace much in their units. .......
171: Tube DIY Asylum, RE: Much better, one question (0.00)
Posted by Russ57 on 2014-06-19, 14:18:32 (184.33.98.230)
Those seem okay (without going back to the schematic and loking up tube data). Big question, did you have to change any wiring? Was everything only related to a misunderstanding as to what pin was cal .......
172: Tube DIY Asylum, RE: No, not at all (0.00)
Posted by Russ57 on 2014-06-19, 13:31:49 (184.33.95.181)
Some amps used very high quality parts. There is no need to replace them. You might find it hard to better them. You may laugh at this but yet you know it is true when it comes to the tubes. Some part .......
173: Tube DIY Asylum, RE: What would help (0.00)
Posted by Russ57 on 2014-06-18, 16:35:21 (74.233.29.54)
Above you listed pin voltages to ground. Now we know that you reported the wrong pin numbers. Please tell us the voltage you now have on which pins. I'd do this with no tubes in place and then with al .......
174: Tube DIY Asylum, RE: Theory help from the guru's please..... (0.00)
Posted by Russ57 on 2014-06-17, 19:12:26 (98.77.241.37)
You should be reading zero volts from pin 3 to ground. The volume pot (VR1) has a certain resistance value to it. You could replace it with a pair of resistors and connect your CD player to the juncti .......
175: Vintage Asylum, RE: Quick question (0.00)
Posted by Russ57 on 2014-05-30, 11:18:20 (165.214.11.82)
Do you offer a "parts kit" for the power supply caps for a Fisher 400? Never thought to ask....just "assumed" you only offered kits for the citation. .......
176: Tube DIY Asylum, RE: I'll try (0.00)
Posted by Russ57 on 2014-05-29, 01:09:18 (184.33.98.45)
You may think I'm being evasive here but the simple fact is....its not easy. First I'd suggest you take a multi-step approach. You wouldn't use only one over current device to protect everything in yo .......
177: Tube DIY Asylum, RE: And I would say this is caused by a lack of understanding. (0.00)
Posted by Russ57 on 2014-05-28, 15:44:34 (184.33.95.4)
One of the neat things about my job is I get to actually test things. Nothing like taking a 2,000 amp breaker and pumping 20,000 amps through it to test how long it takes to trip. Most people don't un .......
178: Tube DIY Asylum, RE: You are really starting to scare me (0.00)
Posted by Russ57 on 2014-05-21, 17:48:27 (184.33.102.77)
Mike, we have seen each other in person. I know you aren't dumb. I really am having a hard time telling if you are being obtuse to cover up for your original post.....or if you are really that clueles .......
179: Tube DIY Asylum, RE: IIRC (0.00)
Posted by Russ57 on 2014-05-19, 17:35:56 (184.33.96.185)
That is a fast acting fuse....roughly same as 3AG series. I suggest you try a slo-blo fuse. .......
180: Tube DIY Asylum, RE: Welllllll...... (0.00)
Posted by Russ57 on 2014-05-17, 13:24:07 (184.33.100.217)
The 8 amp through you heart part was tounge in cheek. I thought it would be obvious....sorry. Your first post made reference to connecting ALL equipment to this isolated/unbonded ground rod. That is w .......
181: Tube DIY Asylum, RE: I'm trying to help here (0.00)
Posted by Russ57 on 2014-05-15, 21:11:57 (98.77.241.167)
The ground rod MUST be bonded to the neutral in order for the circuit breaker to work. Since the ground and neutral bus can ONLY be bonded at the main service then ALL ground rods must be bonded back .......
182: Tube DIY Asylum, RE: Here is a much better link from Mike Holt (0.00)
Posted by Russ57 on 2014-05-15, 19:40:17 (98.77.241.167)
http://www.mikeholt.com/mojonewsarchive/GB-HTML/HTML/Grounding-Part-1-of-12~20041005.php You are missing the important part about ground rods being bonded together....and going back to main panel wher .......
183: Tube DIY Asylum, RE:I think I do (0.00)
Posted by Russ57 on 2014-05-15, 13:55:34 (165.214.11.73)
I "think" wheezer is trying to say....if impedance between new unbonded ground rod and neutral was 25 ohms.....and if potential was 240 volts....then one could not draw more than 9.6 amps in a dead sh .......
184: Tube DIY Asylum, RE: Michael, lets dicusss whats wrong and why it made an improvment (0.00)
Posted by Russ57 on 2014-05-15, 10:50:17 (165.214.11.76)
By now many have run you through the ringer. I would like you to understand why those grounds rods are dangerous. In typical Russ fashion I'll try to lead you to the discovery rather than saying somet .......
185: Tube DIY Asylum, RE: Only an audiophile..... (0.00)
Posted by Russ57 on 2014-05-14, 18:11:54 (184.33.102.200)
Why is it that audiophiles will suppose something that all other disciplines have rejected is right for them? NEC is there for a reason. You don't need to understand those reasons but you do should fo .......
186: Vintage Asylum, RE: I have to ask (0.00)
Posted by Russ57 on 2014-05-12, 13:53:31 (184.33.100.71)
Why this unit? You saw/smelled smoke (yikes). 23 tubes, loads of parts, all in one small chassis (double yikes). I could see a ton of labor in it....60...100 hours perhaps. For the money spent I think .......
187: Vintage Asylum, RE: I'm close (0.00)
Posted by Russ57 on 2014-05-06, 16:15:25 (184.33.102.20)
Duane, what happened when you plugged it in? If you saw smoke and there was a burning tar smell the outlook is....well pricey. FWIW, I work at Mercy Hospital (in the grove) and wheezer is a friend (he .......
188: Tube DIY Asylum, This is so important I hope others don't skip over it (0.00)
Posted by Russ57 on 2014-04-03, 18:26:46 (184.33.98.233)
No big admission here, but I'm not some famous tube amp designer hiding behind an internet moniker. What I am is a glorified "fix-it-man" who has worked in hospitals for the last 40 years. I can tell .......
189: Tube DIY Asylum, RE: I don't think so (0.00)
Posted by Russ57 on 2014-03-25, 11:51:39 (165.214.11.68)
IIRC the west-cap paper in oils have a CPO prefix in the part#. .......
190: Tube DIY Asylum, RE: What are some suggested solder iron temps... (0.00)
Posted by Russ57 on 2014-03-22, 22:04:29 (184.33.98.218)
I typically run between 600-700 for such work. The real answer is to have a good soldering iron that has enough power to complete the process in a few seconds....under five ideally. Solder melts aroun .......
191: Tube DIY Asylum, RE: I reckon you have seen the data sheet (0.00)
Posted by Russ57 on 2014-03-14, 18:33:47 (184.33.96.174)
But if not... http://www.mif.pg.gda.pl/homepages/frank/sheets/095/5/5Z3Pa.pdf I think you will conclude heater current is 3 amps (plus/minus 0.3), cap size is 4uF, 1,700 volts PIV, 250ma cont./750ma p .......
192: Tube DIY Asylum, RE: Do yourself a favor (0.00)
Posted by Russ57 on 2014-03-14, 16:02:02 (184.33.96.174)
Go find some "coke bottle" black plate RCA 5U4GB tubes. At least I think they are 5u4gb....the ones with those curvy sides. Just need to make sure you can supply the 3 amps for the heater (5R4 is only .......
193: Tube DIY Asylum, RE: Shuggie 5z3pa... (0.00)
Posted by Russ57 on 2014-03-14, 13:34:53 (184.33.96.174)
You will see it is also listed as a 5R4 type....which is limited to 4uF as well. What are you looking to do with it? .......
194: Tube DIY Asylum, RE: Shuggie 5z3pa... (0.00)
Posted by Russ57 on 2014-03-14, 11:49:46 (165.214.14.22)
According to the chinese data sheet (keeping in mind I can't read it).....it seems that 4uF is the limit. Any claim in regards to cap size needs to consider the power transformer too. .......
195: Tube DIY Asylum, RE: parallel rectifies (0.00)
Posted by Russ57 on 2014-03-12, 15:27:55 (184.33.102.203)
There are pros and cons to both ways. Call it a personal choice that nobody but you can make. How big is your input cap? A 274B is very limited in that regard. IIRC they are rated for something really .......
196: Tube DIY Asylum, RE: Do you have a schematic? (0.00)
Posted by Russ57 on 2014-03-06, 09:12:27 (165.214.14.22)
A tube rectifier works with a center tapped secondary. A bridge rectifier doesn't. If you have a center tapped secondary you can the bias supply work. If you don't, it is time for plan B. .......
197: Tube DIY Asylum, RE: My bad (0.00)
Posted by Russ57 on 2014-03-02, 16:35:21 (98.77.241.186)
Didn't check his page and didn't mean to put words in your mouth. .......
198: Tube DIY Asylum, RE: I'm with Mr. Death....get horn speakers:) (0.00)
Posted by Russ57 on 2014-03-02, 13:03:29 (108.132.18.82)
Do you have another amp that gives you the slam you are looking for with the same speakers? If so, what is different about it? If not, maybe it isn't the amp. If the amp is basically stock you should .......
199: Tube DIY Asylum, RE: Certainly related (0.00)
Posted by Russ57 on 2014-02-28, 04:42:37 (165.214.14.22)
Check the mounting of the bias supply cap. A lot of folks don't understand it's case is live/hot and needs to be insulated. Needless to say plus end of the cap goes to ground and negative end to bias .......
200: Tube DIY Asylum, RE: Certainly related (0.00)
Posted by Russ57 on 2014-02-27, 17:01:39 (108.132.18.209)
The grid must be negative to the cathode or tube is in full conduction. This can be done by having grid at ground potential and elevating catode with resistor....or by having cathode at ground and gri .......
201: Tube DIY Asylum, RE: Try this (0.00)
Posted by Russ57 on 2014-02-26, 20:43:06 (98.77.242.85)
Look up "J" or "U" style tinnerman nuts. Probably need a 4-40 thread size. http://www.amazon.com/C8114-1024-4-Tinnerman-Style-U-Type-Steel-Carton/dp/B0012XP4B4 .......
202: Tube DIY Asylum, RE: Mk III PIO Cap Values question (0.00)
Posted by Russ57 on 2014-02-26, 14:40:13 (184.33.100.95)
Without getting too technical.....the coupling cap (along with some other parts) determines the lowest (bass) note the amp can play. I would use the Solens to begin with. Give them a couple of months .......
203: Tube DIY Asylum, RE: I would defer to Mr. McShane (0.00)
Posted by Russ57 on 2014-02-25, 16:38:04 (98.77.242.194)
First, glad to know I was wrong and you own an original. Take care of it and know you own something special. Jim has experience with Stu's designs and you would be foolish to overlook that resource. F .......
204: Tube DIY Asylum, RE: I didn't say it was a "POS" :) (0.00)
Posted by Russ57 on 2014-02-24, 19:34:58 (184.33.98.33)
Sometimes you never know if a guy is tweaking an amp he owns....or if he has picked a schematic to follow for a DIY attempt. I thought it might be the latter. I felt that schematic wouldn't be easy to .......
205: Vintage Asylum, RE: This might be painful (0.00)
Posted by Russ57 on 2014-02-24, 19:09:44 (184.33.102.98)
Sometimes we come by something so we decide to build around it. Nothing requires more compromises than building around a set of speakers. IMHO speakers took a drastically wrong turn once solid state a .......
206: Tube DIY Asylum, RE: That is a feedback resistor (0.00)
Posted by Russ57 on 2014-02-24, 18:21:12 (108.132.19.34)
"IF" I wanted to follow that schematic, and that is a big if, I would stay with the values speced. .......
207: Tube DIY Asylum, RE: This is a much bigger question than you imagine (0.00)
Posted by Russ57 on 2014-02-24, 13:37:04 (184.33.103.105)
A signal ground is often thought of as a signal point (or plane), all at the same potential, that serves as a reference for the entire system. The problem with that thought process is it says nothing .......
208: Tube DIY Asylum, RE: And drain the residual voltage (0.00)
Posted by Russ57 on 2014-02-24, 08:01:28 (165.214.14.22)
It is a power supply filter cap. It's job is to attempt to keep the voltage a constant (called good regulation). Its other job is to allow the AC ripple voltage to be shunted to ground insuring you ha .......
209: Vintage Asylum, RE: I see nothing out of order (0.00)
Posted by Russ57 on 2014-02-23, 19:51:26 (184.33.100.179)
The original resistors and caps are what I am used to seeing in fisher equipment. He does mention power supply caps and "paper in oil caps" aren't original (which are obvious). Unit appears very clean .......
210: Tube DIY Asylum, RE: Lets try a different way (0.00)
Posted by Russ57 on 2014-02-23, 19:06:25 (184.33.100.179)
All of what you are saying is correct. However you are only thinking in one direction, the forward direction, when the diode/rectifier is conducting. You liken the diode to a one-way valve, which is 1 .......
211: Tube DIY Asylum, RE: mod to ST-70 (0.00)
Posted by Russ57 on 2014-02-23, 17:07:42 (184.33.100.179)
Yes, the diodes are functioning even if the GZ34 is working correctly. They are not a simple piece of wire regardless of the GZ34. Yes, 1N4007 is okay (diode rating should be 2.8 times the RMS voltage .......
212: Tube DIY Asylum, RE: Wait a sec (0.00)
Posted by Russ57 on 2014-02-23, 11:45:28 (98.77.240.231)
The diodes are in series with the GZ34. The diodes will function as diodes as long as the voltage on the input side is higher than the output side (typically at peak of sine wave after cap is charged .......
213: Tube DIY Asylum, RE: Mostly right (0.00)
Posted by Russ57 on 2014-02-23, 11:19:26 (108.132.18.254)
In addtion....I think it would help with a quick on/off power blink. When amp is first turned on, tube is cold and B+ takes some time to ramp up. Kinda of a built in slow start circuit. On a quick pow .......
214: Tube DIY Asylum, RE: Might be an easier way (0.00)
Posted by Russ57 on 2014-02-22, 21:55:18 (108.132.18.254)
You mention you have a fluke meter. Most of the better ones can measure AC and DC voltages together. The cap is there to block DC voltage from going through it while allowing AC voltage to pass throug .......
215: Tube DIY Asylum, RE: Tube Power Supply question.... (0.00)
Posted by Russ57 on 2014-02-22, 10:51:05 (98.77.241.171)
Perhaps but I don't think it is in your best interest. Better to add capacitance after the choke. A ten uF motor run cap would be a nice choice for that first cap. .......
216: Tube DIY Asylum, RE: Can you measure voltages? (0.00)
Posted by Russ57 on 2014-02-21, 13:59:06 (184.33.94.82)
An o-scope is ideal but a multi-meter will take you a long ways. Looking at the link for the schematic you posted....see the input 12ax7 called v200a? Notice it has 300VDC on the top of R202, a 150K r .......
217: Tube DIY Asylum, RE: With shared resistor doesn't this give DC bias voltage to your speakers? (0.00)
Posted by Russ57 on 2014-02-18, 08:47:16 (165.214.14.24)
With a shared resistor he has no idea what each tube is doing. If both tubes work right and are perfectly balanced all is well as the DC voltages cancel. But assume the worse. Say one tube is darn nea .......
218: Tube DIY Asylum, RE: With shared resistor doesn't this give DC bias voltage to your speakers? (0.00)
Posted by Russ57 on 2014-02-18, 04:41:02 (165.214.14.24)
I would replace the speakers with a dummy load resistor. Fire up the amp with the input shorted (take RCA and connect hot and cold side together). Then measure across that dummy load resistor. You sho .......
219: Tube DIY Asylum, RE: Time Delay (0.00)
Posted by Russ57 on 2014-02-18, 04:28:39 (165.214.14.24)
No, it would not be suitable for what you want. It can't handle that voltage and it is just a delay....no soft start about....just bam, full on. .......
220: Vintage Asylum, RE: It kinda depends (0.00)
Posted by Russ57 on 2014-02-17, 16:10:54 (184.33.97.210)
Some amps used very good parts that age well. Granted those are sorta far and few between. Still I have made some mistakes "upgrading parts" that weren't an upgrade at all! I won't agrue most any elec .......
221: Tube DIY Asylum, RE: With shared resistor doesn't this give DC bias voltage to your speakers? (0.00)
Posted by Russ57 on 2014-02-17, 14:56:33 (184.33.97.210)
Do your have the portion of the secondary connected to the speakers "floating"? Are you determining that you have oscillation because speaker cones are pulsing? Have you tried a dummy load in place of .......
222: Tube DIY Asylum, Did you say "use CFB wiring on the output transformers"? (0.00)
Posted by Russ57 on 2014-02-16, 08:39:04 (184.33.102.212)
If so I'm having a hard time understanding why there would be a cathode bypass cap at all. I'm assuming a CFB winding on the primary of the OPT. I haven't posted, nor been building for quite awhile, s .......
223: Tube DIY Asylum, RE: FWIW (0.00)
Posted by Russ57 on 2014-02-15, 16:15:00 (184.33.100.37)
Guessing you didn't follow the link? "I don't have that schematic in electronic format to send you, but if you buy yourself a copy of my "TubePreamp CookBook" you will find a whole chapter devoted to .......
224: Tube DIY Asylum, RE: Me thinks you are in the wrong forum (0.00)
Posted by Russ57 on 2014-02-15, 10:09:40 (184.33.95.125)
The drivers you own are rather "special". I can now understand your desires. You might do better to ask over on the High Efficiency Speaker Asylum. I'll assume you know some have had bad experiences w .......
225: Tube DIY Asylum, RE: 1/2 wave selenium rectifier with 3 terminals (0.00)
Posted by Russ57 on 2014-02-14, 18:07:07 (184.33.101.214)
Okay, so dumb question here. You only need 151 VDC and likey a lot less amps than 400ma. Again, why use that rectifier? Darn things don't age well, have poor reverse voltage performance, and a whole h .......
226: Tube DIY Asylum, FWIW (0.00)
Posted by Russ57 on 2014-02-13, 16:56:42 (184.33.98.159)
http://www.audioasylum.com/forums/amp/messages/14/146079.html Maybe you could buy the book and get a schematic, some free education, and a better preamp all in one:) .......
227: Tube DIY Asylum, RE: 1/2 wave selenium rectifier with 3 terminals (0.00)
Posted by Russ57 on 2014-02-13, 15:39:27 (184.33.98.159)
Part# would help. It should be on the box. Usually AC input terminals are color coded yellow and DC outputs are red and black for plus and minus. So given that the box says it is half wave....if you h .......
228: Tube DIY Asylum, RE: Question about a resistor on negative feedback circuit (0.00)
Posted by Russ57 on 2013-11-25, 14:53:27 (184.33.99.249)
Well said. Haven't been around in a long time. Warms my heart to see some still around giving solid advice and information. .......
229: Tubes Asylum, RE: Basic speaker matching question (0.00)
Posted by Russ57 on 2013-08-19, 15:52:36 (98.77.241.44)
I just hate to see you make lateral moves. Seems to me you have been down the ST70/A25 path and know where it ends. I'm not saying it isn't an enjoyable walk in the woods. Just that it isn't the only, .......
230: Tubes Asylum, RE: Basic speaker matching question (0.00)
Posted by Russ57 on 2013-08-18, 02:31:07 (165.214.14.21)
Hello Charles, it has been awhile. I'm not that involved with audio these days but I'll share what I learned. I don't think you will like it, but it is what I have found to be true. Speakers are proba .......
231: Vintage Asylum, RE: THORENS TURNTABLE OPINIONS (0.00)
Posted by Russ57 on 2011-04-27, 11:12:10 (72.46.240.196)
Matter of opinion. Many pay more to have the all metal setup. I like the plastic. To me it is better damped and being lighter works better with the stock springs assuming you add some mass from teakin .......
232: Vintage Asylum, For the frugal and cheap guys (0.00)
Posted by Russ57 on 2011-04-25, 05:38:32 (72.46.240.196)
Try motor run caps. You can get them out of old AC's and motors. I like the GE 97F series in particular. The older the better. Just make sure they are run caps, not start caps. .......
233: Tube DIY Asylum, RE: Quiz time to have arguments over :-) (0.00)
Posted by Russ57 on 2011-04-22, 09:44:29 (72.46.240.196)
A transformer is a passive device and a voltage amp is comprised of active devices. A transformer doesn't amplify, it converts or transforms. You might wish to call it an impedance matching device. A .......
234: Tube DIY Asylum, Measure if you can (0.00)
Posted by Russ57 on 2011-04-15, 12:18:57 (72.46.240.196)
A Y connector and a signal generator along with a good meter proves what you "think" you "may" be hearing. .......
235: Tube DIY Asylum, RE: What's the formula for maximum system detail? (0.00)
Posted by Russ57 on 2011-04-12, 11:23:00 (72.46.240.196)
I have never found a true full range speaker. At least nothing I could afford. On the other hand going to a line level crossover and letting each driver have its own amp has been worthwhile for me. :: .......
236: Tube DIY Asylum, Can we agree on this statement then? (0.00)
Posted by Russ57 on 2011-04-12, 11:19:23 (72.46.240.196)
An autotransformer is an electrical transformer in which there is one winding, a portion of which is common to both the primary and the secondary circuits. In other words, the primary and secondary co .......
237: Tube DIY Asylum, RE: Nice question (0.00)
Posted by Russ57 on 2011-04-11, 12:24:26 (72.46.240.196)
I'll await the answer. I'm curious to hear about your speaker plans. I found them much harder than amps. No doubt aggravated by the fact that I didn't have a clue what I was getting into! When do you .......
238: Vintage Asylum, Question, why should a vintage tube receiver sound different than a new tube receiver? (0.00)
Posted by Russ57 on 2011-04-11, 11:51:20 (72.46.240.196)
I will tell you that (IMHO) Sherwood vintage tube products have a cleaner and less "vintage" sound than most. Personally I consider that a good thing:) All the Sherwoods I worked on had caps that I de .......
239: Tube DIY Asylum, RE: It sounds bad for other reasons, not because it is stranded (0.00)
Posted by Russ57 on 2011-04-08, 07:56:32 (72.46.240.196)
Dan, I think you are reaching conclusions not supported by the evidence. I bet if you took that zip cord and had solid wire installed inside it, it still wouldn't sound as good as other options. ::: T .......
240: Vintage Asylum, Hospital engineering wasn't it? (0.00)
Posted by Russ57 on 2011-03-23, 10:01:49 (72.46.240.196)
Mind telling me who you worked for and where? My hospital is about to be sold to one of those evil corporations. I'd hate to be looking for a job right now but it would beat being fired shortly after .......
241: Vintage Asylum, RE: Pioneer D23 electronic crossover (0.00)
Posted by Russ57 on 2011-01-05, 08:04:39 (72.46.240.196)
Marchand. I'd encourage you to consider going 2-way and using a passive network on the tweeter. Everyone is jumping on the digital bandwagon so don't overlook used pro audio equipment. .......
242: Tube DIY Asylum, RE: Nice to see this topic brought up again (0.00)
Posted by Russ57 on 2010-10-29, 10:46:11 (72.46.240.196)
Maybe I'll have to put dust off my learning cap and sit in on this one. Have to see if I kept a pic of that one circuit that Allen called "seriously slick". It was beyond me as I avoid understanding t .......
243: Vintage Asylum, Nice job Jerry, care to comment on horns? (0.00)
Posted by Russ57 on 2010-10-14, 12:11:03 (72.46.240.196)
. .......
244: Tube DIY Asylum, Wimp:) (0.00)
Posted by Russ57 on 2010-10-13, 10:49:48 (72.46.240.196)
I have been busy with other things. First it was target shooting. Lately I have been building fishing rods. A friend is doing his best to drag me back into audio. I see you have gotten the itch again. .......
245: Tube DIY Asylum, Think joules per watt (0.00)
Posted by Russ57 on 2010-10-12, 07:27:06 (72.46.240.196)
Only you can decide what is enough. I tend to side on more is better and like a couple of joules per watt if I can fit it. I don't like electrolytics so space is a limiting factor. Loved the comments .......
246: Tube DIY Asylum, RE: small electrolytic exploded next to cooked 7w resistor- shall I replace? (0.00)
Posted by Russ57 on 2010-09-22, 09:54:15 (72.46.240.196)
It is almost certain that you have a bad EL34. .......
247: Tube DIY Asylum, I'm only an email away:) (0.00)
Posted by Russ57 on 2010-08-11, 08:36:46 (72.46.240.196)
I think you have mine. If not Mitch can put you in touch. I don't remember the schematic you mention. Got a link? I haven't been playing with audio much. I got sidetracked with some other stuff. First .......
248: Tube DIY Asylum, RE: motor run cap - DC voltages... (0.00)
Posted by Russ57 on 2010-08-04, 08:55:43 (72.46.240.196)
I can tell you the 440VAC caps used to have a 1,000VDC rating on the label....FWIW. .......
249: Tube DIY Asylum, I suggest you look at mitsubishi(nt) (0.00)
Posted by Russ57 on 2010-05-03, 10:00:41 (72.46.240.196)
. .......
250: Vintage Asylum, The "other caps in the radio that come off different tubes " (0.00)
Posted by Russ57 on 2009-11-13, 08:55:57 (72.46.240.196)
Are often from the heater connections to ground. Check and see what tube pim numbers they are on and we can advise. If they are what I think the original small ceramics should still be fine. ::: TOPIC .......
251: Tube DIY Asylum, An easy one to sub (0.00)
Posted by Russ57 on 2009-10-11, 11:16:35 (12.77.249.62)
Try an american blackplate 6cg7. GE is my least favorite and raytheon my most. Sylvania are easier to find and pretty nice. They have a chrome divider shield so are easy to spot. Only require a change .......
252: Tube DIY Asylum, RE: Questions about the rectifier (0.00)
Posted by Russ57 on 2009-08-29, 11:02:53 (209.214.1.247)
The transformer resistance is intended to limit the current draw through the rectifier at startup when used with a cap input filter. The Dynaco 70 violated that rule and the mullards often lasted 30-4 .......
253: Tube DIY Asylum, RE: Questions about the rectifier (0.00)
Posted by Russ57 on 2009-08-29, 00:34:18 (209.214.1.245)
If you can afford a mullard great. If not, one of the russians will do (sovtek). I don't like JJ...had nothing but trouble. Stay with the GZ34 and don't worry about transformer resistance as long as y .......
254: Tube DIY Asylum, Danger (0.00)
Posted by Russ57 on 2009-08-27, 07:23:13 (72.46.240.196)
You need to read up on how a voltage doubler works. The big point is the outside case of one of those caps has a couple hundered volts on it and needs to be well insulated. Russ .......
255: Tube DIY Asylum, RE: New Problem (0.00)
Posted by Russ57 on 2009-08-26, 12:57:12 (208.60.249.63)
A few things. First off when you say the transformer is rated for 300ma is that its AC rating or its DC rating into a cap input filter? Those are very different things. A bad cap, a bad rectifier tube .......
256: Tube DIY Asylum, RE: Troubleshooting Push-Pull 2A3 (0.00)
Posted by Russ57 on 2009-08-23, 20:52:17 (209.214.0.197)
The polarity of the feedback loop. We are talking AC so maybe it would be better for me to say reverse phase?? Just reverse the transformer leads to the plates of the 2A3's to fix. It is easy to do an .......
257: Tube DIY Asylum, RE: Troubleshooting Push-Pull 2A3 (0.00)
Posted by Russ57 on 2009-08-23, 20:14:10 (209.214.0.197)
My first two suggestions would be to remove the feedback loop on both channels and on the 76 tube to remove the volume pot and place a 100K resistor from grid to ground (at the tube socket and no conn .......
258: Tube DIY Asylum, Nah, I think you miss Doug's point (0.00)
Posted by Russ57 on 2009-07-28, 17:40:53 (209.214.1.85)
The 6n1p would have a hard time getting much under 100 volts on its plate. The 6n6p could run much lower, down around 50 volts. It is a worthwhile point. Mu and bias point have a lot to do with swing .......
259: Tube DIY Asylum, Wagner's Der Ring des Nibelungen or .... (0.00)
Posted by Russ57 on 2009-07-17, 07:29:10 (72.46.240.196)
what Doug mentioned. Piano is generally good too. Most recordings are limited/compressed so Tom's fireworks recording is going to have a higher crest factor. Russ .......
260: Tube DIY Asylum, We don't want the truth, we want GREEN(nt) (0.00)
Posted by Russ57 on 2009-07-09, 06:34:40 (72.46.240.196)
. .......
261: Tube DIY Asylum, Please describe how you would measure (0.00)
Posted by Russ57 on 2009-07-05, 20:29:56 (76.108.133.227)
As in; what you would measure, where, and with what. Russ .......
262: Tube DIY Asylum, RE: How perfect can you make one? (0.00)
Posted by Russ57 on 2009-07-05, 20:28:28 (76.108.133.227)
It might prove interesting to show a plot of a "good supply". It would have to use values realistic for tube amps so no 10,000 uF caps:) Russ .......
263: Tweakers' Asylum, FYI (0.00)
Posted by Russ57 on 2009-06-26, 21:21:33 (209.214.0.82)
Take a look at the link provided. It is for a type GMA, 5 by 20mm fast acting fuse. If you look at the graph on page two you will see the 1 amp fuse will hold about 1.5+ amps at 100 seconds. Stating t .......
264: Tube DIY Asylum, RE: There is a logical progression (0.00)
Posted by Russ57 on 2009-06-26, 16:49:59 (209.214.0.82)
Most of us start off the same way. We "refine" what we have. Over a period of time some gain knowledge and understanding. They invest in test equipment and formal training. It does not take long befor .......
265: Tweakers' Asylum, On the metal ends of the fuse... (0.00)
Posted by Russ57 on 2009-06-26, 16:28:19 (209.214.0.82)
there will be a series of letters, like AGC or MDL......or a series of numbers, like 312 or 311. That is the type of fuse and you can look it up on-line. Contray to what was said above, all fuses will .......
266: Tube DIY Asylum, You have very serious problems... (0.00)
Posted by Russ57 on 2009-06-18, 11:41:36 (72.46.240.196)
with your amp and your attitude. Try being polite and making an effort to learn. Frankly most of us couldn't give a crap if you blow up your amp and burn down your house with the way you are acting. J .......
267: Tube DIY Asylum, RE: Tech help needed (0.00)
Posted by Russ57 on 2009-06-18, 04:46:04 (72.46.240.196)
I'm not quite sure what you are asking. A 0.6 amp draw on a 3 amp transformer shouldn't cause the voltage to change much if at all. Perhaps you want to know what resistor you would have to use to deli .......
268: Tweakers' Asylum, RE: How to measure input/output impedance (0.00)
Posted by Russ57 on 2009-06-16, 19:38:20 (209.214.1.41)
No, you don't need this device. Tubes amps typically have very high input impedances with 470,000 ohms a common value. A simple way is to use a pot at least ten times the expected output impedance. Us .......
269: Tube DIY Asylum, I have never seen a VTL schematic (0.00)
Posted by Russ57 on 2009-06-13, 21:51:57 (208.60.248.2)
Like you said...just the little black book. It seems they used the same design for all their amps. Every one I have seen has a 12at7....and they always ran the output tubes way beyond rated specs..... .......
270: Tubes Asylum, Off topic but.... (0.00)
Posted by Russ57 on 2009-06-12, 07:05:33 (72.46.240.196)
Any experience with digiscoping? I have a spotting scope and the Ex has cameras...both point and shoot as well as DSLR's. Seems a waste to use the scope only to see bullet holes. I need some info to g .......
271: Tube DIY Asylum, I don't know about that (0.00)
Posted by Russ57 on 2009-06-05, 14:39:32 (72.46.240.196)
Fuses don't blow when people think they will. Fuses are required to carry a certain % over their rated voltage for a certain period of time. Look into and I think you will be surprised. One could also .......
272: Tube DIY Asylum, RE: So you guys may think !! (0.00)
Posted by Russ57 on 2009-06-05, 07:38:13 (72.46.240.196)
If the bias supply is derived from a tap off the B+ winding it will change the same % per wall voltage changes. If I was looking for maximum safety I'd think in terms of a relay coil wired to the bias .......
273: Tube DIY Asylum, Is it possible to ask why you like low current driver tubes? (0.00)
Posted by Russ57 on 2009-06-03, 19:49:17 (208.60.249.60)
Jeff, I'm looking to learn and not to find fault. As you may have noticed I avoided saying how a bias supply should be built for such a reason. However I do find it curious that you should come to fin .......
274: Tube DIY Asylum, I'll take a different approach (0.00)
Posted by Russ57 on 2009-06-02, 09:11:09 (72.46.240.196)
Others can fight about how to design a good bias supply. In theory little current is needed and in push-pull you get to cancel equal noise. So often they were wimpy and half wave with small caps. Inst .......
275: Tubes Asylum, The 12AT7 is the place to start (0.00)
Posted by Russ57 on 2009-06-01, 17:05:30 (209.214.0.101)
IMHO the differences between a bad 12AT7 is much larger than the difference between a bad 12AX7. The GE 5star 6201 is the best cheap 12AT7 I have found. They towards strong bass but the highs suffer c .......
276: Tube DIY Asylum, Why no mention of a transformer? (0.00)
Posted by Russ57 on 2009-05-25, 01:00:39 (209.214.0.167)
Wouldn't that be the commercial solution to the problem (I'm assuming phase = polarity in this discussion)? For the brave at heart, try making a recording of what comes out of your speakers. Play that .......
277: High Efficiency Speaker Asylum, A good, cheap, cool running bass amp huh? (0.00)
Posted by Russ57 on 2009-05-23, 07:22:48 (209.214.1.28)
For those of us the bi/tri amp and live in the tropics that doesn't sound bad at all. How many watts can I get? Do they handle a reactive load okay? Russ .......
278: Tube DIY Asylum, Are they both built and operated to the same standards? (0.00)
Posted by Russ57 on 2009-05-21, 09:25:45 (72.46.240.196)
It isn't fair to compare a cap input class AB1 push-pull with a choke input class A1 SET. Keep the field level and I'd say they are close enough to be considered equal. If one went by measured distort .......
279: Tube DIY Asylum, I want to audition them too! (0.00)
Posted by Russ57 on 2009-05-20, 16:47:22 (209.214.1.170)
It appears they don't export:( Maybe we can arrange a group buy if enough of us call and express interest? Maybe we need to ask to speak to Jack in person? Russ .......
280: Tubes Asylum, What about the output transformer? (0.00)
Posted by Russ57 on 2009-05-20, 16:39:26 (209.214.1.170)
We could argue about rather or not adjusting a phase inverter to give the best distortion spectrum (as in more 2nd) is de-tuning or tuning! Am I reading your post correctly? You seem to say one should .......
281: Tubes Asylum, RE: What's the best output pentode/tetrode strapped as a triode? (0.00)
Posted by Russ57 on 2009-05-19, 05:54:58 (72.46.240.196)
Don't overlook the lowly 6V6. Triode strapped it is a very nice tube. Power is low. I only get about 2 watts in push pull class A1. Russ .......
282: Tube DIY Asylum, I don't jam in, I jam on! (0.00)
Posted by Russ57 on 2009-05-15, 09:45:24 (72.46.240.196)
Your questions have already been answered by me in the past. I'm sorry you don't remember. In any event I did not ask you a question. Even if I did I see no need to justify anything. The bottom line i .......
283: Tube DIY Asylum, Oh it gets better (0.00)
Posted by Russ57 on 2009-05-15, 04:27:58 (72.46.240.196)
Just ask him what his equipment is. Or better yet, look over his previous posts and determine for yourself. Given what he admits to owning I don't see how he can make the claims he does about "picky h .......
284: Vintage Asylum, no high end on Lowthers? (0.00)
Posted by Russ57 on 2009-05-10, 18:11:30 (209.214.1.40)
Dang, the ones I heard were ear drillers. Interesting. The guy has since turned them in basszillas, a 3-way design with the lowther run open baffle and a ribbon up top, electronic crossover on the low .......
285: Vintage Asylum, Way to go Bro! (0.00)
Posted by Russ57 on 2009-05-10, 17:52:30 (209.214.1.40)
Hunting sucks where I am....deer are the size of a starved dog. In the northern part of the state they do have some nice ones but not where I am:( The only thing close is wild boar....and I don't mean .......
286: Tube DIY Asylum, On air dielectric (0.00)
Posted by Russ57 on 2009-05-10, 10:30:17 (208.60.249.84)
Awhile back I posted about a somewhat different wiring method I decided to try. In a nutshell I glued the caps upside down under the top plate in a tall chassis. I used shielded twisted pair run in fr .......
287: Vintage Asylum, LOL.... (0.00)
Posted by Russ57 on 2009-05-10, 10:08:16 (208.60.249.84)
You know, there are a lot of ways to skin a cat:) The snob factor can get you thinking it has to have chokes and directly heated triodes. Don't get me wrong, I do think they are best. But pentodes hav .......
288: Vintage Asylum, Not really (0.00)
Posted by Russ57 on 2009-05-04, 05:24:32 (72.46.240.196)
It just depends how much work you want to do and what your skill level is. A 12BH7/12AU7/6CG7 with a common CCS on the cathodes tied to the negative rail would certainly do the job. I'd wager it would .......
289: Vintage Asylum, If we assume it to be correct (0.00)
Posted by Russ57 on 2009-05-03, 09:19:04 (209.214.1.123)
In the interest of helping, why do you think that tube was chosen? Fisher was well engineered and didn't do things on a lark. I see a 12ax7 voltage amp direct coupled to a 12ax7 split-load cap coupled .......
290: Vintage Asylum, Actually (0.00)
Posted by Russ57 on 2009-05-02, 18:19:39 (209.214.1.2)
This is what I found. Site wasn't in english. Seems like a lot to drive 8417's. Most have cost a pretty penny in its day and just about impossible to retube today. If one had the 8417's I don't think .......
291: Vintage Asylum, Uh....none (0.00)
Posted by Russ57 on 2009-05-02, 16:00:13 (209.214.1.2)
That tube is a twin pentode not a twin triode. You could add extra sockets and use el84's.....or something along this line....but this requires a fair amount of work and knowledge. Without knowing mor .......
292: Dynaco-Doctor Forum, Might want to verify the cathode resistor value (0.00)
Posted by Russ57 on 2009-05-01, 06:59:31 (72.46.240.196)
If voltages are holding steady as you adjust the bias pots....and the transformer is humming more....I'd want to be sure that resistor is really 15.6 ohms. Personally I like each EL34 to have its own .......
293: Tube DIY Asylum, Why tin? (0.00)
Posted by Russ57 on 2009-05-01, 06:10:25 (72.46.240.196)
Because it is corrosion resistant. Sometimes those qualities are important and sometimes it doesn't matter. Good luck trying to resolder unplated stranded copper wire after it has been in the bilge of .......
294: Tube DIY Asylum, It is hard to get good info (0.00)
Posted by Russ57 on 2009-04-29, 16:23:56 (209.214.0.184)
Actually a lot of their caps have paper......but they may also have a film layer too:) So I guess it depends upon what someone means by a "paper in oil" cap. GE has made their web site impossible over .......
295: Tube DIY Asylum, Ever think of building one? (0.00)
Posted by Russ57 on 2009-04-28, 13:45:25 (209.214.1.120)
I wish I knew more about them. I'd like to build one, tube based of course, that didn't require all that feedback on the low pass. I guess that would require inductors??? Paul Joppa has mentioned he h .......
296: Tube DIY Asylum, Which cross-over? (0.00)
Posted by Russ57 on 2009-04-28, 07:23:17 (72.46.240.196)
I'd like to hear what you are using. I'm not thrilled by my options and haven't been able to decide. Line level passive is just too much of a load for any sane tube preamp. Russ .......
297: Propeller Head Plaza, Wow, I'm sorry (0.00)
Posted by Russ57 on 2009-04-19, 14:09:15 (209.214.0.186)
Dang, who am I to pass judgment:) If I came across in such a manner I sincerely apologize. I was only mentioning my experiences. I have been caught up in systems, with great resolution, where I found .......
298: Tube DIY Asylum, Dear Jeff, (0.00)
Posted by Russ57 on 2009-04-18, 16:44:52 (209.214.1.156)
Why is it so impossible for you to believe that many of us are happy with what we have? Why do you remain convinced that we are wrong and would change our minds if only we had the experiences you had? .......
299: Propeller Head Plaza, I wonder what question you are trying to resolve (0.00)
Posted by Russ57 on 2009-04-18, 16:10:47 (209.214.1.156)
Reading between the lines, and considering your post below, I get the feeling you are trying to judge things by comparison. Personally I don't care if system A is “better†than system B I only care ab .......
300: Propeller Head Plaza, What "designs" do you like now? (0.00)
Posted by Russ57 on 2009-04-15, 22:27:14 (209.214.0.164)
Given what you say, if you like solid-state gear, I wouldn't bother. If you like tubes then there are compelling reasons to consider building you own stuff. If you feel there is no inherent advantage .......
301: Tube DIY Asylum, Having seen some Quicksilvers (0.00)
Posted by Russ57 on 2009-03-25, 05:40:28 (72.46.240.196)
The original F-dyne caps are pretty good so don't throw the old ones away. The first cap I'd replace would be the big blue one on the top of the amp. The original is way too big. Try to fit a small ch .......
302: Tube DIY Asylum, But aren't those curves... (0.00)
Posted by Russ57 on 2009-03-22, 06:54:29 (209.214.1.78)
taken on a plane wave tube? That isn't the way one would listen to them. FWIW I run an 18sound compression driver with their XT1086 horn. I much perfer it to my morel dome tweeters (but I don't have t .......
303: Tube DIY Asylum, Hmmmm...interesting comment (0.00)
Posted by Russ57 on 2009-03-21, 19:15:44 (209.214.1.70)
I might be inclined to agree if we are talking full/wide range cone drivers. But then I'd say one is trying to get too much out of a single driver. When I think about efficiency in speakers my mind go .......
304: Tube DIY Asylum, Only Mike can say (0.00)
Posted by Russ57 on 2009-03-20, 18:52:37 (209.214.0.211)
Or better yet, show us as you did. I must admit I am curious. Russ .......
305: Vintage Asylum, Very good guess AJ. (0.00)
Posted by Russ57 on 2009-03-20, 07:44:03 (72.46.240.196)
The only 24 ohm resistors I see on the schematic are just that. I do like the sound of a wire wound resistor but for protection purposes a metal film is a better choice. I don't know the actual operat .......
306: Tube DIY Asylum, The solution is easy (0.00)
Posted by Russ57 on 2009-03-18, 18:17:13 (209.214.0.228)
Russian mail order caps give the prettiest waveforms by far and per dollar. American ones are ugly gold diggers by comparison. Anyone who claims the Russian mail order caps cause direct currency leaka .......
307: Tube DIY Asylum, On the one that is reversed (0.00)
Posted by Russ57 on 2009-03-12, 07:37:01 (72.46.240.196)
That creates a negative voltage supply. It is a very important supply as it controls the output tubes (guessing bias supply from info provided). You want to replace those bias supply caps. Use care as .......
308: Tube DIY Asylum, You can't test them that way (0.00)
Posted by Russ57 on 2009-03-12, 04:37:59 (72.46.240.196)
When testing devices it is always best to un-solder one side if you aren't sure. Some of the digital meters have a diode check function. A diode is intended to pass current in one direction but block .......
309: Tube DIY Asylum, Maybe I can help a little (0.00)
Posted by Russ57 on 2009-03-11, 20:43:51 (209.214.0.176)
The TO-220 you mention isn't a rating. It is the "package" or physical dimensions. Compare it with a normal diode which is a DO-41 package. Basically diodes and rectifiers are the same thing as far as .......
310: Tube DIY Asylum, No doubt a lot is missed on me (0.00)
Posted by Russ57 on 2009-03-11, 18:22:01 (209.214.0.176)
I just got off the phone with my daughter who was asking about some speakers she saw at a thrift store. I asked if she had hooked up the last ones I got for her. She said she hadn't even hooked up the .......
311: Tube DIY Asylum, Dude (0.00)
Posted by Russ57 on 2009-03-11, 17:30:40 (209.214.0.176)
That reads like you are trying to convince yourself! Women on fishing boats! Say it ain't so. If she gives a darn what the boat looks like, how is she gonna handle the smell of rotten bait not to ment .......
312: Tube DIY Asylum, And the data sheet says???? (0.00)
Posted by Russ57 on 2009-03-10, 16:02:13 (208.60.249.111)
You are over. But you already knew I knew that or I wouldn't be asking:) More to the point, a lot of the new producton tubes can't handle the maximum allowable values. I'd like to think we can get by .......
313: Tubes Asylum, My bad(nt) (0.00)
Posted by Russ57 on 2009-03-10, 04:36:54 (72.46.240.196)
. .......
314: Tubes Asylum, Only if you limit the choices (0.00)
Posted by Russ57 on 2009-03-09, 17:07:59 (208.60.249.54)
If you include directly heated tubes, those with rim lock bases, those with top caps (and the list goes on). Then the tubes you have named might not crack some people's top 100 leave alone top five. T .......
315: Tube DIY Asylum, Speakers? (0.00)
Posted by Russ57 on 2009-03-08, 18:05:10 (208.60.249.42)
Did I mention speakers?? I know we have both been playing with speaker design for a bit. Are you still running open baffle? I need to get off my lazy ass and give the open baffle bass a try. Boy is it .......
316: Tube DIY Asylum, I'd say he is over the limit (0.00)
Posted by Russ57 on 2009-03-08, 17:57:46 (208.60.249.42)
Jim, what would you advise for a grid leak resistor value (cathode bias) for the 6550/KT88 family? I'm pretty sure he has GE 6550 tubes. I'd rather he pick a value that is safe for all the new tubes. .......
317: Tube DIY Asylum, So are we all friends again? (0.00)
Posted by Russ57 on 2009-03-08, 05:57:51 (209.214.1.205)
Dang I didn't mean to start a cat fight. Like I said, the post was supposed to be about GE 97F caps. Okay, I'll admit that I did get my panties in a wad when I felt you discounted the asylum members t .......
318: Tube DIY Asylum, For the record Jim (0.00)
Posted by Russ57 on 2009-03-07, 15:36:45 (209.214.0.119)
I have not bought, nor used, the K40's. A friend of mine has. While working on his amp, I pointed out to him that one of the K40's had about 1.5VDC on the downstream side of it. Others here have repor .......
319: Tube DIY Asylum, Tell me about the rest of the speakers (0.00)
Posted by Russ57 on 2009-03-06, 18:07:14 (208.60.249.87)
I'm just beginning to find out you are into bi/tri-amping. I went that way a couple/few years ago. Let's just say I had a life changing speaker experience at a fellow inmate's house! Russ ::: TOPIC:: .......
320: Tube DIY Asylum, Wrong (0.00)
Posted by Russ57 on 2009-03-06, 17:58:42 (208.60.249.87)
The 97F series are not paper in oil caps. They are metallized polypropylene. The big difference is the new ones are made in Mexico. Mike I think you have a bad case of paper and oil of the brain syndr .......
321: Vintage Asylum, RE: One critical point (0.00)
Posted by Russ57 on 2009-03-06, 17:44:19 (208.60.249.87)
Many amps of that vintage used a selenium rectifier for the bias supply. They often decrease in voltage output as they age. Plus they spew posion gas when they go. Make sure you look into that and rep .......
322: Tube DIY Asylum, How much work do you want to do? (0.00)
Posted by Russ57 on 2009-03-05, 17:17:15 (209.214.0.156)
Personally I'm not a fan of can caps. I'd rather see you clean out the old can caps and re-stuff them with new electrolytics. Panasonic makes a good resonable priced cap. Try to get a 105C rated cap. .......
323: Vintage Asylum, That is better:) (0.00)
Posted by Russ57 on 2009-03-05, 16:15:51 (209.214.0.156)
No a regular EL84 won't do in this amp. It seems to me they run the 7189 well over its rating!! The only new tubes that I'd consider trying are EL-84M. Jim McShane is a good guy to contact. He would p .......
324: Vintage Asylum, Hmmm (0.00)
Posted by Russ57 on 2009-03-05, 09:32:50 (72.46.240.196)
Try this one then. It might be the same, I didn't look. http://hhscott.com/pdf/sd/299B_3_4s.JPG EL34's are totally wrong for that amp. Do you know anything about its history? Is it possible someone ma .......
325: Vintage Asylum, Let's locate a schematic. (0.00)
Posted by Russ57 on 2009-03-05, 07:22:37 (72.46.240.196)
Does this look right? Just what is the problem? Russ .......
326: Tube DIY Asylum, You will have to forgive CJ (0.00)
Posted by Russ57 on 2009-03-04, 11:32:52 (72.46.240.196)
Having never heard a Sherwood he actually thinks he gets better sound with his PAS preamp. Those that have heard Sherwood tube gear.....try not to talk too much:) Russ .......
327: Tube DIY Asylum, If you use new production tubes (0.00)
Posted by Russ57 on 2009-03-04, 06:12:52 (72.46.240.196)
The new tubes have no problem with that voltage. The EH sound good and are cheap. Don't worry about it. Do measure the heater voltages though and add dropping resistors as required. If the output tube .......
328: Vintage Asylum, RE: If you had to choose... power supply caps question (0.00)
Posted by Russ57 on 2009-03-04, 04:42:09 (72.46.240.196)
The voltage doesn't matter as long as it is equal or higher than the original. Ditto on capacitance unless you have a tube rectifier. If so the first cap needs to be within ratings of the rectifier. L .......
329: Tube DIY Asylum, And that is why we share experiences here (0.00)
Posted by Russ57 on 2009-03-03, 08:42:32 (72.46.240.196)
I'll watch out for things. I reckon most of my stuff never sees more than a fraction of the rated watts and that may help. I have used a few Caddocks but mostly in DAC's and such. Mills are clean but .......
330: Tube DIY Asylum, Interesting, never had a Mills fail (0.00)
Posted by Russ57 on 2009-03-03, 06:00:41 (72.46.240.196)
Any idea why they failed? Perhaps too many volts across them? Russ .......
331: High Efficiency Speaker Asylum, RE: active filter subwoofer (0.00)
Posted by Russ57 on 2009-03-02, 17:50:00 (209.214.1.212)
You can make a high pass filter within the SET amp with coupling cap choices/grid leak resistors, cathode bypass caps, and the like. There is no need for any op-amps. Rather or not this is needed woul .......
332: Tube DIY Asylum, I don't think you can reach that conclusion (0.00)
Posted by Russ57 on 2009-03-01, 17:45:38 (209.214.0.7)
I have records recorded way before the Beatles that are fantastic. It has been my experience that many rock & roll recordings suck. Most jazz records from the same time period are superior, so I don't .......
333: Tube DIY Asylum, I'd us the tooth brush and alcohol (0.00)
Posted by Russ57 on 2009-03-01, 17:22:15 (209.214.0.7)
Your friend can better advise you. Ultrasonic cleaners that run alcohol are rather special. If he has one he would know best. All I can say is ultrasonic cleaning isn't as gentle a process as one migh .......
334: Tube DIY Asylum, I have some small knowledge (0.00)
Posted by Russ57 on 2009-02-28, 15:20:05 (209.214.1.48)
I work at a hospital and it is used to clean surgical instruments. I have heard it claimed that it will dull the edge on a scapel. My brother has one to clean his guns and is unconcerned about dulling .......
335: Tube DIY Asylum, more likely it is tin plated (0.00)
Posted by Russ57 on 2009-02-28, 14:40:18 (209.214.1.48)
It never hurts to have clean surfaces. On the other hand you don't want to remove plating nor use something corrosive that will cause problems later on. I'd try and solder normally and see how it goes .......
336: Tubes Asylum, Nope, pure garbage, I'll dispose of them for you:) (0.00)
Posted by Russ57 on 2009-02-27, 18:51:32 (209.214.1.222)
I really have to wonder where some of these stories got their start. Russ .......
337: Tube DIY Asylum, IMHO (0.00)
Posted by Russ57 on 2009-02-27, 15:39:16 (209.214.0.125)
If I had a circuit that had a resistor doing 4 watts at idle I'd want a 16 watt part. For that wattage I'd look at a pair of mills or an aluminum clad dale. All things equal a wire wound resistor has .......
338: Tube DIY Asylum, Hold on Doc (0.00)
Posted by Russ57 on 2009-02-27, 15:26:57 (209.214.0.125)
R1 and R3 are not simple resistors. They are L-pads. Best you keep the originals. Good new ones aren't cheap and cheap new ones aren't good. Russ .......
339: Tube DIY Asylum, In case you couldn't tell (0.00)
Posted by Russ57 on 2009-02-27, 10:14:20 (72.46.240.196)
Those of us that are into tubes hate the association with "warm vintage sound". Tubes done right have clean treble with good range but without that grating sound common to poor quality solid state and .......
340: Tube DIY Asylum, Wagner's "Tristan und Isolde" (0.00)
Posted by Russ57 on 2009-02-26, 14:15:44 (209.214.0.123)
Knowing you Mike I doubt that it where you picked it up but one never knows. Russ .......
341: Vintage Asylum, No, not a SX-88 (0.00)
Posted by Russ57 on 2009-02-25, 09:18:45 (209.214.0.213)
I'm a nice guy and all but I ain't stupid:) If I had one of those I'd restore it and pocket the money. I have a SX-28, considered one of the best pre WWII units, and the SX-42, the one that won awards .......
342: Tube DIY Asylum, We need a double blind test (0.00)
Posted by Russ57 on 2009-02-24, 17:15:01 (209.214.0.113)
Interesting that statement was made here. As you no doubt know the results are not clear cut. It is one of those things that seems simple but proves not to be so easy after all. And we wonder why we c .......
343: Tube DIY Asylum, Maybe there is another solution? (0.00)
Posted by Russ57 on 2009-02-24, 16:55:10 (209.214.0.113)
I have to assume your speaker bass modules are line powered and derive a signal from the output transformer of your SET amp. Have you tried lifting the ground on the power going to the bass modules? W .......
344: Vintage Asylum, Save your money, see me next time you are down here (0.00)
Posted by Russ57 on 2009-02-24, 16:31:02 (209.214.0.113)
I have two. Both are in rough condition comestically but both are very desirable models. I'm sure we can work out a deal. Russ .......
345: Tube DIY Asylum, Go here (0.00)
Posted by Russ57 on 2009-02-24, 07:18:44 (72.46.240.196)
http://www.illinoiscapacitor.com/ Some people like them a lot. I haven't tried them. I like a polypropylene and tin, film and foil type personally. Russ .......
346: Tube DIY Asylum, Try here (0.00)
Posted by Russ57 on 2009-02-23, 15:20:15 (209.214.0.171)
This looks like it should do. Russ .......
347: Tube DIY Asylum, Is it a cap input filter? (0.00)
Posted by Russ57 on 2009-02-22, 17:11:23 (209.214.1.59)
I "think" this all about limiting maximum current draw at startup into discharged caps. I also know Dynaco went beyond specs and rectifier life was still okay. I'd say don't worry if into a choke inpu .......
348: Vintage Asylum, Hey Doug (0.00)
Posted by Russ57 on 2009-02-22, 15:25:08 (209.214.1.59)
Could I get you to email me a schematic? It sounds perfect for Wheezer's needs. I'm willing to abide by any agreement you want to protect your work. If nothing else could I send you one to look over? .......
349: Tubes Asylum, Are the original tubes still in place? (0.00)
Posted by Russ57 on 2009-02-21, 05:08:26 (209.214.1.241)
The Fisher came stocked with Tele's and mullards. You basically can't buy better. Jim McShane has some good info on circuit changes required when running new production output tubes. Russ ::: TOPIC:: .......
350: Tube DIY Asylum, Unrelated Mitch (0.00)
Posted by Russ57 on 2009-02-20, 12:19:03 (72.46.240.196)
If you want to turn that circuit I sent you into a pic file and post it here for review that is cool with me. Just don't put values on the resistors as I didn't calculate those yet. It was just a "con .......
351: High Efficiency Speaker Asylum, I don't know if this will help (0.00)
Posted by Russ57 on 2009-02-12, 16:20:08 (209.214.0.80)
You have guys here that know so much more than I do about speakers. What I found is the pro audio crossovers tend to be harsh on the trebel. For me it was better to go passive between the mid and horn .......
352: Tweakers' Asylum, One point to keep in mind (0.00)
Posted by Russ57 on 2009-02-12, 05:27:11 (72.46.240.196)
If you can wire your gear for 240VAC you get code approved balanced power for free in the USA:) Russ .......
353: Tube DIY Asylum, I think you got confused a bit (0.00)
Posted by Russ57 on 2009-02-11, 16:00:32 (208.60.249.95)
Understandable since we have been talking about two different amps. Lets start with the 6550 stereo amp. Now you know I insist on a list Mitch so: 1) Circuit is limited to one 9 pin socket per channel .......
354: Tube DIY Asylum, That is even stranger Jack (0.00)
Posted by Russ57 on 2009-02-11, 11:50:26 (72.46.240.196)
Either the schematic is wrong, you need new glasses, or there is something important you left out. Russ .......
355: Tube DIY Asylum, And most of the amps he references... (0.00)
Posted by Russ57 on 2009-02-11, 09:49:01 (72.46.240.196)
have to sound like crap. I'd say he has a lot of balls to put down your work but frankly I doubt he has a set to be found. Russ .......
356: Tube DIY Asylum, What is the bandwith of a 5687? (0.00)
Posted by Russ57 on 2009-02-11, 09:36:45 (72.46.240.196)
I rather doubt you are hearing past 100kHz and a 5687 will do well beyond that. Russ .......
357: Tube DIY Asylum, Mighty strange operating points (0.00)
Posted by Russ57 on 2009-02-11, 09:30:37 (72.46.240.196)
I have a hard time seeing how a 12ax7 with 125 volts can drive an EL34. I also have a hard time seeing how an ultra-linear EL34 works with 128 volts. If these are the actual operating voltages I think .......
358: Tube DIY Asylum, And that is the problem (0.00)
Posted by Russ57 on 2009-02-09, 07:37:10 (72.46.240.196)
He only has one 9 pin socket per channel and there are no dual pentodes in a 9 pin tube. Sure, you can make a split load inverter swing close to 20% of the B+. Now try finding a 9 pin triode that will .......
359: Tube DIY Asylum, On the 12AT7 (0.00)
Posted by Russ57 on 2009-02-08, 14:07:51 (209.214.1.34)
Eli, what plate load and bias point would you pick for the 12at7? How would it be coupled to the LTP? Russ .......
360: Tube DIY Asylum, If there is no best..... (0.00)
Posted by Russ57 on 2009-02-08, 11:04:05 (209.214.1.34)
Maybe we can tell him which ones aren't up to the task? I should mention that Wheezer is a friend and I have made suggestions. I would be the first one to tell him not to take my advice as gospel. My .......
361: Tube DIY Asylum, But if they leak..... (0.00)
Posted by Russ57 on 2009-02-04, 05:19:15 (72.46.240.196)
you might decide they weren't so cheap after all if they take out a set of output tubes. Call me silly but I think parts should do their intended job. A cap should block DC. Period. 100%. End of story .......
362: Tube DIY Asylum, That is what doesn't add up for me either (0.00)
Posted by Russ57 on 2009-02-02, 07:50:05 (72.46.240.196)
The 12AX7 is running a little over 1ma. It is direct coupled to the 12BH7 which should have a gain of about 0.9. Hard to see miller as the problem. I'm not sure what the problem is but I'd think a 12A .......
363: Vintage Asylum, RE: Need a good replacement for a Mylar capacitor (0.00)
Posted by Russ57 on 2009-02-01, 04:48:51 (209.214.1.53)
Charles, I don't know what values you need. 200 volts is a very high for solid state and there is no need to go higher than the rail voltage. Have you looked at the panasonic ECQ-P series I mentioned .......
364: Tube DIY Asylum, Just say wow:) (0.00)
Posted by Russ57 on 2009-01-30, 15:19:34 (209.214.1.195)
Isn't it interesting how different people can experience the same thing and draw very different conclusions? .......
365: Tube DIY Asylum, Do you have one of these switches on your amp? (0.00)
Posted by Russ57 on 2009-01-30, 14:59:06 (209.214.1.195)
I think you are assuming the switch compromised the sound when thrown a certain way. Isn't it possible that the switch improved the sound when thrown one way? Have you added a switch to your amp and l .......
366: Tube DIY Asylum, I have a question for you (0.00)
Posted by Russ57 on 2009-01-30, 14:36:59 (209.214.1.195)
I should know this but I think I'm getting dumber in my old age:) Say you have an amp with a 5U4 rectifier and due to todays higher line voltages the heater voltages are too high. A couple of resistor .......
367: Tube DIY Asylum, So you feel there is no such thing as talent? (0.00)
Posted by Russ57 on 2009-01-30, 14:29:15 (209.214.1.195)
Dennis, my dad grew up on a farm in northern michigan. He left after he served in WWII and moved to florida where I was born. Now my two brothers and I can fix anything we need to. We can hunt and fis .......
368: Tube DIY Asylum, Depends on the cap (0.00)
Posted by Russ57 on 2009-01-30, 10:27:38 (72.46.240.196)
Most electrolytics have a surge rating. Check your caps. If you put caps in series be sure to put a resistor across each cap. Russ .......
369: Vintage Asylum, You think the wife would fall for that? (0.00)
Posted by Russ57 on 2009-01-28, 07:27:33 (72.46.240.196)
You might have just hit on the perfect excuse by mistake. Don't advertise or abuse it. Wait until it is something you really want. Blame it on the damn drugs the doctor prescribed. Might even be good .......
370: Tube DIY Asylum, The ones in my friend's amp leaked too(nt) (0.00)
Posted by Russ57 on 2009-01-27, 08:15:45 (72.46.240.196)
. .......
371: Tube DIY Asylum, If I can but in:) (0.00)
Posted by Russ57 on 2009-01-26, 15:00:51 (209.214.0.6)
Dave, there have been a few things going on with the amp. Last time I was vsited some things were ironed out and the rest I have tried to help with over the phone. Mitch has been experimenting with di .......
372: Vintage Asylum, Lot of choices (0.00)
Posted by Russ57 on 2009-01-25, 09:19:11 (208.60.249.81)
First off, I haven't tried alot of the following options because I wanted to keep all my gear full range capable. So I have mostly been using line level active. In that case I have leaned towards liki .......
373: Vintage Asylum, Where do you live? (0.00)
Posted by Russ57 on 2009-01-23, 17:51:46 (209.214.1.108)
You might find someone is close by. Pretty much everyone starts off with vintage amps. First they rebuild them, then they modify them, then they build from scratch. Each step is a huge advance. You do .......
374: Vintage Asylum, Have you tried.... (0.00)
Posted by Russ57 on 2009-01-23, 17:40:02 (209.214.1.108)
any of the Sansui's? I find them warmer than the "B" series Marantz's but not as vieled as the blue faced ones. All mylar caps are NP. A true film and foil is best but if you don't have room stacked f .......
375: Tube DIY Asylum, Well said (0.00)
Posted by Russ57 on 2009-01-14, 08:32:15 (72.46.240.196)
I can't think of a single person that hasn't felt better about their equipment once they have made the plunge and learned how to measure things. They were all plently happy before. An ignorance is bli .......
376: Tube DIY Asylum, CJ, that is some fantastic B.S. but we know better(nt) (0.00)
Posted by Russ57 on 2009-01-13, 08:24:43 (72.46.240.196)
. .......
377: Tube DIY Asylum, Consider this (0.00)
Posted by Russ57 on 2009-01-12, 14:14:35 (209.214.0.250)
A SE transformer must carry all the DC current. A push-pull transformer operates under the assumption that it only has to carry the unbalanced current (which should be as small as possible). A SE tran .......
378: Tube DIY Asylum, Not really (0.00)
Posted by Russ57 on 2009-01-12, 14:00:13 (209.214.0.250)
I see a lot of misunderstanding with regards to ground fault outlets. Contray to what many assume a GFI receptacle does not measure current on the ground wire in any way. Instead it compares current o .......
379: Tube DIY Asylum, But the ST70 isn't pentode(nt) (0.00)
Posted by Russ57 on 2009-01-08, 11:07:37 (72.46.240.196)
. .......
380: Tube DIY Asylum, Perhaps an example will prove Doug's point (0.00)
Posted by Russ57 on 2009-01-08, 10:47:01 (72.46.240.196)
CJ, there are many ways to derive and inject feedback. If the goal is to reduce to output impedance of an EL34 why do you consider it best to inject a signal from the output transformer secondary into .......
381: Dynaco-Doctor Forum, Let me ask you this (0.00)
Posted by Russ57 on 2009-01-08, 10:36:22 (72.46.240.196)
I just want to check something to be sure. Todays wall voltages can often have the heater voltages higher than ideal. Running those prized EL34's at 7 volts isn't going to help them last. Easy enough .......
382: Tube DIY Asylum, Use a resistor in series with CCS (0.00)
Posted by Russ57 on 2009-01-03, 04:45:22 (208.60.249.121)
Make the grid voltage of the LTP what your voltage amps plate is. For these reasons best to use a voltage amp that does well at a lowish plate voltage like a 6922 (or others). Russ .......
383: Tube DIY Asylum, You don't need to get that fancy (0.00)
Posted by Russ57 on 2009-01-02, 18:00:21 (209.214.0.123)
A medium mu triode direct coupled to a LTP with a CCS cathode load will be far more than adequate. The 6SN7 is a fine tube and I use the 9 pin version, a 6cg7, with good results. The LTP should be run .......
384: Tube DIY Asylum, You are correct (0.00)
Posted by Russ57 on 2009-01-02, 14:12:25 (209.214.0.123)
I have not looked at the Blackburn board. What you are describing is a cascode direct coupled to a concertina inverter. The concertina "should" drop 1/4 of the B+ across its load resistors and 1/2 acr .......
385: Tube DIY Asylum, Where I think it gets done a lot..... (0.00)
Posted by Russ57 on 2009-01-02, 13:44:56 (209.214.0.123)
is inside a push-pull amp. You can use a long tailed pair as a first stage. Drive one grid with a single ended input and ground the other grid. Then have your two outputs feed the grids of a different .......
386: Tube DIY Asylum, Jeff I mean no disrespect (0.00)
Posted by Russ57 on 2009-01-02, 07:04:56 (209.214.1.162)
In some ways your own post proves my point. At one time you might have argued that stiff regulation was best. Now, due no doubt to new experiences, you have changed your mind. It is only logical that .......
387: Tube DIY Asylum, I have another question for him too (0.00)
Posted by Russ57 on 2009-01-01, 21:53:44 (209.214.0.97)
I get the feeling that a lot of what he says is based on an amp built a long time ago. This isn't so with regards to the power supply stuff but maybe it is when it comes to grid leak resistors and suc .......
388: Tube DIY Asylum, What tube do you like? (0.00)
Posted by Russ57 on 2009-01-01, 21:47:29 (209.214.0.97)
I'm forced into having to use one on a friend's amp to drive 6550's. I was leaning towards a 5687 direct coupled to a 12B4 but I felt I couldn't justify the added cost. I think we will end up with a 6 .......
389: Tube DIY Asylum, Jeff (0.00)
Posted by Russ57 on 2009-01-01, 21:33:59 (209.214.0.97)
You can probably do it but they won't be clean punches and you might mess up your punch. I use an impact wrench and have to rotate the punch a few times. Also you have to punch twice unless you drill .......
390: Tube DIY Asylum, You say normal is 25 volts on that 300 ohm cathode resistor (0.00)
Posted by Russ57 on 2008-12-30, 04:34:48 (72.46.240.196)
Watts = volts squared divided by resistor value. So 625/300=2.083 watts. A 3 watt part is not adequate. I would use a 10 watt wire wound resistor. Chris has some good suggestions. Russ .......
391: Tube DIY Asylum, I guess you saw the scope pics?? (0.00)
Posted by Russ57 on 2008-12-29, 14:24:55 (209.214.0.83)
I'll admit it took me a few minutes to see why there was such a profound change when he only drove one channel. Each pair of EL34's had a 500 ohm cathode resistor and I didn't notice the jumper wire l .......
392: Tube DIY Asylum, Hey Gents (0.00)
Posted by Russ57 on 2008-12-27, 22:29:56 (208.60.249.35)
With luck I'll get over there tomorrow and have a look see. The basic circuit is a 12ax7 voltage amp direct coupled to a 6922 split load inverter. I don't know what plate voltages these tubes are seei .......
393: Vintage Asylum, In a feedback loop (0.00)
Posted by Russ57 on 2008-12-17, 05:44:01 (72.46.240.196)
You can do some reading and get a handle on how phase shifts are created in an amp and how that can cause trouble for a feedback loop. The important part is to make sure that the gain of an amplifier .......
394: Tube DIY Asylum, Hey Bud (0.00)
Posted by Russ57 on 2008-12-15, 16:45:54 (209.214.0.99)
Refresh my memory please. What do you have for an amp and preamp these days? You still have the KEF speakers right? Russ .......
395: Tube DIY Asylum, The dryer plug should be on a 30 amp breaker (0.00)
Posted by Russ57 on 2008-12-13, 13:43:44 (209.214.0.16)
12 gauge is okay for 20 amps but if you have a 30 amp breaker go with 10 gauge. 240VAC is balanced power already! No need to compromise that monster transformer by cheaping out now:) Russ ::: TOPIC:: .......
396: Tube DIY Asylum, It will work great put you need more than a 120 volt outlet (0.00)
Posted by Russ57 on 2008-12-13, 13:03:33 (209.214.0.16)
Sure it is nice to have overhead put you won't have anymore than what you put into the transformer. A standard wall receptacle won't cut it. You really should move up to a 240 receptacle on at least a .......
397: Tube DIY Asylum, I'll probably head in your direction (0.00)
Posted by Russ57 on 2008-12-09, 19:27:12 (209.214.1.25)
If I am honest with myself I'd have to say I'm looking for a "sexy solution". I'll have to see if I can get Wheezer to post a pic of the inside of the amp. You will get a better idea of why I am bent .......
398: Tube DIY Asylum, I don't think so (0.00)
Posted by Russ57 on 2008-12-09, 19:09:28 (209.214.1.25)
I can't see the 6V6's making that. EL84's might make it in class AB1. But if you push the el84's to that point the distortion will be high and I doubt you will be satisfied. Russ .......
399: Tube DIY Asylum, How much do you need? (0.00)
Posted by Russ57 on 2008-12-09, 17:03:52 (209.214.1.201)
That may be your deciding factor. I have a triode strapped PP 6V6 amp and is not quite 2 watts in class A1. Might not seem like much but they are "magic watts":) Russ .......
400: Tube DIY Asylum, I know what you mean (0.00)
Posted by Russ57 on 2008-12-09, 05:42:06 (72.46.240.196)
I told the owner he needs to identify what he wants to change. I suspect what he really wants is to gain an idea of how different circuits sound. He recently obtained some measuring gear and found he .......
401: Tube DIY Asylum, Okay, Eli, Ginger, Naz...64K question (0.00)
Posted by Russ57 on 2008-12-07, 19:53:40 (209.214.0.54)
What changes would you make to the amp? There are a couple of fine points on the schematic that aren't right. I suspect there may be a feedback loop from the primary UL tap point back to the 12ax7. I .......
402: Tube DIY Asylum, Glad I asked (0.00)
Posted by Russ57 on 2008-12-06, 17:40:34 (209.214.1.178)
I'd say cap from pot's wiper to grid. Resistor (high ohms) from grid to battery. Battery to ground. Try adding (big?) cap across battery. .......
403: Tube DIY Asylum, battery between pot and ground right? (0.00)
Posted by Russ57 on 2008-12-06, 17:14:50 (209.214.1.178)
. .......
404: Tube DIY Asylum, My 2 cents (0.00)
Posted by Russ57 on 2008-12-06, 17:08:40 (209.214.1.178)
I thought the idea was to run extra current through the cathode resistor to allow it to be smaller and (thereby) have less degeneration of the 12ax7 which would remove the need for the cathode bypass .......
405: Tube DIY Asylum, RE: Please show fixed bias in 2 stage on drivers... (0.00)
Posted by Russ57 on 2008-12-06, 16:31:34 (209.214.1.178)
Now sure I am following. Is there a resistor in series with the battery? The input signal needs an impedance to work into and the battery has little. Russ .......
406: Tube DIY Asylum, How I know you are better:) (0.00)
Posted by Russ57 on 2008-12-06, 16:27:21 (209.214.1.178)
Because you know which book to look in! I wasn't sure if/how resistors from B+ to cathode come into play. If % output power isn't too hard I'll take that (logs always screw me up). TIA, Russ ::: TOPI .......
407: Tube DIY Asylum, Eli (0.00)
Posted by Russ57 on 2008-12-06, 15:06:13 (209.214.1.247)
Can/would you calculate for him how many dB of feedback he has? I told him to post as I'm not so good at feedback calulations. It would be appreciated if you showed the math. Russ .......
408: Tube DIY Asylum, Are you running the foreplay too high? (0.00)
Posted by Russ57 on 2008-12-05, 20:42:07 (209.214.1.202)
You shouldn't have the volume set low on the crossover. I'd leave the volume for the bass off and crank the others to max, turn the preamp down low and play some music. Increase volume to normal level .......
409: Tube DIY Asylum, RE: Stupid SE amp questions (0.00)
Posted by Russ57 on 2008-12-05, 11:32:36 (72.46.240.196)
You said, "I understand that the signal is applied to grid and this modulates the electrons coming off the cathode to the anode, which is the output. Makes perfect sense. I guess I do not get how the .......
410: Tube DIY Asylum, Great amp to learn on (0.00)
Posted by Russ57 on 2008-12-04, 13:51:12 (209.214.0.132)
Tube amps are easy to fix. Sure you can pay but you could buy a soldering iron and give it a go. I'd say new power supply caps are in order. That is the round aluminum cylinder thing on top. It contai .......
411: Tweakers' Asylum, Try a little measuring (0.00)
Posted by Russ57 on 2008-12-04, 13:38:29 (209.214.0.132)
I don't know your schematic. If the 300b's normally have 70 volts on the cathode but saw 200 volts then grid current/A2 operation may have taken place. If the driver was not robust enough it may have .......
412: Tube DIY Asylum, Please read his post again (0.00)
Posted by Russ57 on 2008-12-04, 12:16:58 (72.46.240.196)
Eli, this is a cut and paste. I'd like to use the amp on my speakers and thought it would be nice to add another amp driven by the 222 for a sub. or speakers in another room. I no longer want two syst .......
413: Tubes Asylum, How bad depends on how big (0.00)
Posted by Russ57 on 2008-12-04, 12:08:10 (72.46.240.196)
Dynaco sorta went past the published rating with the stock cap size so adding to it makes matters worse. Plus the old cap is likely to being leaking (compounding the problem). If you are lucky enough .......
414: Tweakers' Asylum, Did you replace the 300B's? (0.00)
Posted by Russ57 on 2008-12-04, 12:04:07 (72.46.240.196)
15 minutes cooking at that current could take a lot of life of the cathodes. But in answer to your question, yes I would replace the bypass caps and cathode resistors. Russ .......
415: Tube DIY Asylum, RE: Question (0.00)
Posted by Russ57 on 2008-12-03, 22:13:54 (209.214.0.40)
Looking quickly at some of the operating points, do you think it is the preamp section giving the sound he likes or the power amp section? I notice the voltage amp pentode is running at a rather low p .......
416: Tube DIY Asylum, delta I viewed over a relatively long period of time (0.00)
Posted by Russ57 on 2008-12-03, 17:01:30 (209.214.0.24)
That is what I said. The average current is a constant but the instantenous current is changing. It is possible to get away from that with CCS/differential/push-pull but it isn't the norm. You darn su .......
417: Tubes Asylum, Sue, come see us at dynaco doctor forum (0.00)
Posted by Russ57 on 2008-12-03, 16:41:12 (209.214.0.24)
Long time no hear. Last I knew you had a fisher?? The big blue (added) cap will stress the tube rectifier as the original is still in place. Joe sells a cap board that will address all your problems. .......
418: Tube DIY Asylum, It's about voltage regulation (sorta/kinda/mostly:) (0.00)
Posted by Russ57 on 2008-12-03, 09:13:59 (72.46.240.196)
As music plays the current goes up and down in a tube even if it is class A. In class A the "average current" is a constant but not what happens instant but instant. So the voltage to the tube will ch .......
419: Tube DIY Asylum, I guess I don't understand ...again (0.00)
Posted by Russ57 on 2008-12-01, 15:29:06 (209.214.1.202)
I have been lucky to hear some great solid state. IMHO good tubes only win out in their ability to create a 3-d soundstage. When it comes to good solid state I'll say tubes also win out in timbre. Whe .......
420: Tube DIY Asylum, CJ, why this love affair with grid leak biasing? (0.00)
Posted by Russ57 on 2008-12-01, 14:22:36 (209.214.1.202)
As I understand it grid leak bias can't help but cause distortion. On a postive going input signal grid current is drawn (so this electron stream never reaches the plate). This in turn means a negativ .......
421: Tube DIY Asylum, You of all people (0.00)
Posted by Russ57 on 2008-11-29, 16:50:29 (209.214.1.197)
Interesting you should mention Mike. I suppose given where I posted it is a logical conclusion. I was thinking more along the lines of....those that disagreeing with result in a lengthy suspension. If .......
422: Tube DIY Asylum, How about voting for "inmate who profits most from asylum"?(nt) (0.00)
Posted by Russ57 on 2008-11-29, 12:26:12 (209.214.0.105)
. .......
423: Tube DIY Asylum, Maybe in time I will "understand" a 45 SET (0.00)
Posted by Russ57 on 2008-11-29, 12:17:13 (209.214.0.105)
I have heard many whom I value sing the praises of a low powered SET amp. Sometimes it makes me doubt my ears and my equipment. I'll admit that it could do for a treble amp with my compression drivers .......
424: Tube DIY Asylum, I guess I see it differently (0.00)
Posted by Russ57 on 2008-11-29, 11:49:35 (209.214.0.105)
Yes, the parts haven't changed. Although I'd argue many are better such as passive parts. Good, current production, iron doesn't take a back seat either IMHO. I'd submit what has really changed is the .......
425: Tube DIY Asylum, How sad (0.00)
Posted by Russ57 on 2008-11-27, 10:08:35 (209.214.1.22)
If what I am hearing out of the mouths of some is what they actually think I have to wonder why they are here. We have parts we can apply to tube circuits that weren't around in the past. We are lucky .......
426: Tube DIY Asylum, You have a vivid imagination! (0.00)
Posted by Russ57 on 2008-11-27, 07:52:07 (208.60.249.59)
“If one's home got the size of an auditorium (not for me, please), then what you heard with your friends some 4000W "active 4-way system" should fit the shoes of the type of "live performance" you wer .......
427: Cable Asylum, FYI, the T&B terminals are copper (0.00)
Posted by Russ57 on 2008-11-25, 15:05:40 (209.214.1.51)
I have been using them for decades. Damn fine terminal. Tin over copper does better than silver in salt air environments too. I don't see (maybe better to say I don't agree with) the reasons for brass .......
428: Cable Asylum, Politics it is (0.00)
Posted by Russ57 on 2008-11-25, 14:35:47 (209.214.1.51)
I'll admit to voting for McCain. I could handle the concept of Sarah dealing with things at home (not that I like it mind you). The idea of her on the international stage scared the hell out of me. Be .......
429: Cable Asylum, ROFLMAO!!!!! (0.00)
Posted by Russ57 on 2008-11-25, 13:08:33 (72.46.240.196)
Fruit plugs....now why didn't I think of that. Every time he brings up fruit the only plug that comes to mind is a triple ripple plug. Russ P.S. And I was doing so well at ignoring.....sigh:) ::: TOP .......
430: Tube DIY Asylum, Different in what way? (0.00)
Posted by Russ57 on 2008-11-25, 13:02:38 (72.46.240.196)
I have been to many concerts. I wouldn't be surprised if it is over a thousand by now. In the past it was mostly rock. Lately it has been more folk. When I lived in Nashville I did my share of country .......
431: Cable Asylum, RCA's have been used for speaker connections (0.00)
Posted by Russ57 on 2008-11-25, 12:08:44 (72.46.240.196)
Maybe you are ignorant of this fact? .......
432: Tube DIY Asylum, Well it could be worse (0.00)
Posted by Russ57 on 2008-11-25, 11:54:51 (72.46.240.196)
I was accused of not knowing what a live concert sounds like! There are probably more live concerts in Miami in a week than there are in Canada in a year:) FWIW, I think the stuff you are doing is a w .......
433: Cable Asylum, There is only one thing worse (0.00)
Posted by Russ57 on 2008-11-25, 11:36:41 (72.46.240.196)
RCA/phono plug. Much worse than a banana plug IMHO. Russ .......
434: Tube DIY Asylum, The AMT (0.00)
Posted by Russ57 on 2008-11-22, 04:50:02 (208.60.249.89)
The cabinets ended up in the garbage. Despite the rosewood they were very poorly built. The heil tweeter was reused. I don't know the fate of the rest of the drivers but the quality did not impress me .......
435: Tube DIY Asylum, Tom, if you have a meter and you can solder you can handle this (0.00)
Posted by Russ57 on 2008-11-21, 14:11:28 (208.60.249.89)
It would appear you have a fixed bias amp. This would mean you send negative bias voltage to your output tubes and then make an adjustment to read a certain voltage across the 10 ohm resistor that ble .......
436: Tube DIY Asylum, An abortion? (0.00)
Posted by Russ57 on 2008-11-21, 13:27:48 (208.60.249.89)
I was already okay on amps. I learned in a hurry that speakers aren't near as easy to build. As I mentioned there were three of us. One guy had Lowthers in a medallion cabinet. He built the basszilla. .......
437: Tube DIY Asylum, While you should replace your speakers (0.00)
Posted by Russ57 on 2008-11-21, 12:03:01 (72.46.240.196)
I had the privilage of visting a local forum member's house. It was the first time I had heard a fully active 4-way system. The tweeters were stage accompany ribbons which, IIRC, are 120dB/watt but ca .......
438: Propeller Head Plaza, Those whales aren't so stupid:) (0.00)
Posted by Russ57 on 2008-11-20, 16:13:42 (209.214.0.56)
IIRC very low hertz in water can travel upwards of 1,000 miles. I have heard low bass (in a house) that was inaudible to my ears but shook the glass windows. I could feel it course through my body. So .......
439: Tube DIY Asylum, A somewhat off topic question for you Jeff (0.00)
Posted by Russ57 on 2008-11-20, 15:09:00 (209.214.0.56)
Jeff, if you don't mind, would you tell us what equipment you listen to these days? I'd like to know sources, preamp, amp, speaker, genre of music, etc. Anything and everything you are comfortable men .......
440: Tube DIY Asylum, Not quite meaningless (0.00)
Posted by Russ57 on 2008-11-20, 14:38:41 (209.214.0.56)
It says a lot about CJ. Too bad nobody gave the guy any help though. Makes me feel like this forum is getting as meaningless as the prop-head forum. Russ .......
441: Tube DIY Asylum, See John Swenson's post below(nt) (0.00)
Posted by Russ57 on 2008-11-20, 14:33:37 (209.214.0.56)
. .......
442: Tube DIY Asylum, Then I apologize as that was not my intent (0.00)
Posted by Russ57 on 2008-11-19, 13:49:45 (209.214.0.237)
I was trying to say that the endless bickering that has been going on (IMHO) does not make anyone look good. I did not intend for anyone to think I was calling them a fool. Russ .......
443: Tube DIY Asylum, Ray to the rescue again (0.00)
Posted by Russ57 on 2008-11-19, 10:37:50 (72.46.240.196)
All I can think to add is something my dad told me long ago. "Son, never argue with a fool in public. People might not be able to tell the difference." Russ .......
444: Tube DIY Asylum, He does have a point and we are trying to help (0.00)
Posted by Russ57 on 2008-11-18, 15:35:39 (209.214.0.94)
Even in the post I made below I could name questions that went unanswered. Please don't think I am picking on you. I could think of a number of things that I know you like and we could find several fo .......
445: Tube DIY Asylum, I wouldn't bother with bucking (0.00)
Posted by Russ57 on 2008-11-18, 15:05:12 (209.214.0.94)
I'm not sure what the design voltages are but you can't be more than a few % high. No big deal just make sure the heater voltage isn't high. For the other things you bring up: You can sub in a tube re .......
446: Tube DIY Asylum, Thanks Ray, I'll take two (0.00)
Posted by Russ57 on 2008-11-18, 10:55:50 (72.46.240.196)
Never heard of that one. Are they common where you are? Russ .......
447: Tube DIY Asylum, I doubt it matters on the B+ (0.00)
Posted by Russ57 on 2008-11-18, 10:50:03 (72.46.240.196)
I can understand that perhaps you are trying to follow a schematic but rarely is anything that critical. If you have a schematic we can comment. Probably all you need to do is use a couple of resistor .......
448: Tube DIY Asylum, Hmmmm, not sure (0.00)
Posted by Russ57 on 2008-11-17, 18:44:12 (209.214.1.73)
I started to say yes but IIRC it was as a voltage regulator. Typically it was choke loads that were used which act much the same (albeit lower Z and limited bandwith). You can't beat a CCS for the cos .......
449: Tube DIY Asylum, You are right, autonomous action(nt) (0.00)
Posted by Russ57 on 2008-11-17, 17:23:52 (209.214.1.73)
. .......
450: Tube DIY Asylum, Do you think tube amps sound better? (0.00)
Posted by Russ57 on 2008-11-17, 17:15:50 (209.214.1.73)
Can I assume it is safe to say it wouldn't be a hobby if you didn't? Wires/cables do make a difference. It is just a matter of how far you go (like a CCS on a tube amp). Like I say silver wire stuff i .......
451: Tube DIY Asylum, A suggestion and some questions (0.00)
Posted by Russ57 on 2008-11-17, 16:34:19 (209.214.1.73)
Gusser, if you click on the letter next to Stephen's name you can get a link to his website. From there you can learn a bit about him. Have you done so? If not, why not? It helps if we understand each .......
452: Tube DIY Asylum, I wasn't talking audio really (0.00)
Posted by Russ57 on 2008-11-17, 10:50:41 (72.46.240.196)
Not to put anyone down but audio is pretty easy compared to a lot of other engineering feats. Heck even I can cobble up something on the kitchen table that works. Probably couldn't build a workable lu .......
453: Tube DIY Asylum, If you don't learn from what you do... (0.00)
Posted by Russ57 on 2008-11-17, 09:04:32 (72.46.240.196)
Then that would be a truly close minded and pitiful excuse for an engineer. Some of the comments I read here sure don't sound like engineers I know. Yes some get stuck in their ways and like to stay w .......
454: Tube DIY Asylum, My cat brought me a live bird. (0.00)
Posted by Russ57 on 2008-11-15, 21:31:28 (209.214.1.47)
Does that make him a better cat? My cat said any cat can bring home a dead bird but it shows great restraint to keep it alive and fresh. I offered to put the bird in a cage. He offered to piss on my b .......
455: Vintage Asylum, film caps or electrolytics? (0.00)
Posted by Russ57 on 2008-11-15, 19:12:22 (209.214.0.77)
Personaly, I wouldn't touch a vintage electrolytic despite the fact that a select few wf=here very good quality. Vintage film caps are another story. Some are prized for sound but should be used with .......
456: Tubes Asylum, I will 3rd it (0.00)
Posted by Russ57 on 2008-11-15, 13:46:04 (209.214.0.111)
I see a lot of guys with vintage gear concerned about today's higher wall voltages. I also tell them don't worry about B+ but look at heater voltage. Russ .......
457: Tube DIY Asylum, I don't know if this is related (0.00)
Posted by Russ57 on 2008-11-13, 12:01:30 (72.46.240.196)
I recall a tube that was a pair of triodes in one bottle. It was different as it had two cathodes but one of the grids was connected to the other cathode. It allowed greater power and operated well wi .......
458: High Efficiency Speaker Asylum, BTW (O.T.) (0.00)
Posted by Russ57 on 2008-11-12, 15:17:40 (208.60.249.68)
Well maybe it is on target? Shot my first match on 11/8 and got a 1583 out of a possible 1600. I was hoping for a 1580 so I was quite pleased with myself. My house is a tad too small for a 100 yard ra .......
459: Tube DIY Asylum, It does make you wonder (0.00)
Posted by Russ57 on 2008-11-12, 14:59:59 (208.60.249.68)
The foreplay has never been accused of having too little gain! Allen, if you would, please comment on why you advised not to use a cathode bypass cap on a 6dj8/6922/7308. My friend wheezer would like .......
460: Tube DIY Asylum, Well said, I like that! (0.00)
Posted by Russ57 on 2008-11-12, 14:54:03 (208.60.249.68)
Keep that up and some might get very confused about what the local electrical ultility is selling them:) I tend not to buy the power factor thing. I agree matters get worse all the time and I admit I .......
461: Dynaco-Doctor Forum, RE: HEXFREDS on (0.00)
Posted by Russ57 on 2008-11-12, 04:45:53 (72.46.240.196)
I have used hexfreds before and they are an improvment. These days I'd spend a bit more and go with the cree schottky (1,200 volt ones). If you want a lower priced part the UF4007 is a nice step up fo .......
462: Tube DIY Asylum, LOL! (0.00)
Posted by Russ57 on 2008-11-10, 11:56:04 (72.46.240.196)
You will have to remind me now and then:) Maybe Allen will chime in. Russ .......
463: Tube DIY Asylum, I wouldn't overlook your mood either (0.00)
Posted by Russ57 on 2008-11-10, 04:05:09 (72.46.240.196)
I use a lot of power conditioning and notice the same thing. Also used to have audio get togethers on Sunday mornings. We all found it a little hard to get in the mood that early in the day. Russ ::: .......
464: High Efficiency Speaker Asylum, In that case (0.00)
Posted by Russ57 on 2008-11-09, 15:23:46 (209.214.0.142)
You might want to do a little research and even hire an acoustical consultant type. You know, measure twice and cut once:) Golden ratio seems a good place to start, but what do I know! Russ ::: TOPIC .......
465: High Efficiency Speaker Asylum, And the wife says???? (0.00)
Posted by Russ57 on 2008-11-08, 17:33:52 (209.214.1.101)
I find myself single for the first time in my life well into my 50's. It does let me get into my hobbies but I sure wouldn't let my hobbies ruin a good domestic situation. Just keep things in prespect .......
466: Tube DIY Asylum, I told you this long ago (0.00)
Posted by Russ57 on 2008-11-08, 02:54:23 (209.214.1.46)
You will have less gain, higher output impedance, and (IIRC) a reduction in higher order distortion. Allen is the man with this tube so lets see what he has to say. Best to make him aware of your circ .......
467: Tube DIY Asylum, I use to see "retard chokes" (0.00)
Posted by Russ57 on 2008-11-07, 16:41:25 (208.60.249.69)
I doubt one could buy such a part anymore. IIRC they were more likely to be used as plate stoppers in instrument/organ PPP amps with the danger being from sustained single hertz notes. Could such a pa .......
468: Tube DIY Asylum, While we are at it, what about G2 and anode stoppers? (0.00)
Posted by Russ57 on 2008-11-07, 04:43:10 (72.46.240.196)
I notice some amps have resistors on G2 and some don't. How do you feel about them? What if the amp is ultra-linear (or PPP)? Would you use a resistor on the anode if it was PPP (i.e. four el34's per .......
469: Tube DIY Asylum, brilliant indeed, give that man a guinness (0.00)
Posted by Russ57 on 2008-11-05, 18:07:36 (208.60.249.66)
I'm trying to get a handle on your snivets comment. I have some oddball tubes. One of these days I might have to make use of such things. Do you pick a G3 bias point based on the lowest G2 current? I .......
470: Tube DIY Asylum, I think you have a problem (0.00)
Posted by Russ57 on 2008-11-05, 17:05:14 (208.60.249.66)
You don't have a center tap and I doubt they were made to handle DC current. I hope I am wrong and someone else can see a way to use them for output transformers. Do you have a brand and model#? Russ .......
471: Tube DIY Asylum, In your case (0.00)
Posted by Russ57 on 2008-11-05, 17:00:21 (208.60.249.66)
Galvanic isolation. Hard to think of much else if it is 1:1. You don't need it to do phase splitting but if it was a step up maybe it would allow a reduction in number of stages or different choices i .......
472: Tube DIY Asylum, What Naz said plus.... (0.00)
Posted by Russ57 on 2008-11-05, 16:16:38 (208.60.249.66)
The 6dj8/6922/7308 family is a tough tube to work with. Throw in the fact that (IMHO) only two companies made a good one and things get tougher still. Good ones sell for silly money and still go micro .......
473: Tube DIY Asylum, Never have tried a pentode CF (0.00)
Posted by Russ57 on 2008-11-05, 16:03:26 (208.60.249.66)
Honestly I don't feel the need for a CF all that often but I agree that a pentode should make a better one. After that long winded formula Jack pulled out, and his habit of citing names, I felt the me .......
474: Tube DIY Asylum, I might have already asked this but.... (0.00)
Posted by Russ57 on 2008-11-05, 12:17:24 (72.46.240.196)
Does Marchand publish the schematic? If so, do you have the link? Also, did you buy anything, like the PCB's from Marchand? Russ .......
475: Tube DIY Asylum, I'd say Allen's preamp smokes Bill's any day (0.00)
Posted by Russ57 on 2008-11-03, 13:09:51 (208.60.249.16)
Jack, sometimes I get the feeling you have no idea who some of the people here are. Go buy that preamp if you want. This is a diy forum. We have the gall to think we can build better than what we can .......
476: Tube DIY Asylum, RE: IIRC (0.00)
Posted by Russ57 on 2008-11-03, 12:59:29 (208.60.249.16)
I don't have a calculator handy but they don't appear to have equal energy storage. Make the tube amps cap about 750uF and you are close(r). Throw in the fact that the tube amp might have energy stora .......
477: Tube DIY Asylum, I cheat (0.00)
Posted by Russ57 on 2008-11-03, 12:53:17 (208.60.249.16)
I use my computer. Maybe you don't trust John Broskie's tube cad? The info Eli gave you is correct. Russ .......
478: Tube DIY Asylum, And (0.00)
Posted by Russ57 on 2008-11-03, 10:41:44 (72.46.240.196)
Offhand I'd say the output Z of a 6922 is about 1/8 of the output Z of a 12ax7. Rather or not that makes someone a blockhead for using a 12ax7 might depend on what they need the tube to drive. Russ : .......
479: Tube DIY Asylum, Eric, I wish I could be of more help (0.00)
Posted by Russ57 on 2008-11-02, 20:23:21 (209.214.1.78)
All the more because I'd like to see some nice discussion around here. But as I said I am not qualified. I suggest you search under my name for "current mirror". That thread (about CCS and current mir .......
480: Tube DIY Asylum, Yes, we have a long way to go (0.00)
Posted by Russ57 on 2008-11-02, 19:32:01 (209.214.1.78)
I bet our insurance agent and loved ones are glad though:) Russ .......
481: Tube DIY Asylum, Face it Henry (0.00)
Posted by Russ57 on 2008-11-02, 19:29:27 (209.214.1.78)
One can only accomplish a real break through if they are irrational and uneducated. Any rational and trained person simply has too much baggage to have any original thoughts. It is only natural that y .......
482: Tube DIY Asylum, Reminds me of a question I once asked (0.00)
Posted by Russ57 on 2008-11-02, 18:36:34 (209.214.1.78)
It was about adding a current mirror. Still this might get you thinking. I did not build it and it is not my design. I don't consider myself qualified to discuss it. Russ .......
483: Tube DIY Asylum, John (0.00)
Posted by Russ57 on 2008-11-02, 18:23:01 (209.214.1.78)
I would confirm the PCB info from an independent source. I have some Vit.Q caps that were made in the 70's by Commonwealth Sprague. A lot of people like the Russian POI caps. I have not heard them. To .......
484: Tube DIY Asylum, IIRC (0.00)
Posted by Russ57 on 2008-11-02, 05:26:39 (208.60.249.93)
Energy storage in capacitors goes by the square of the voltage. The voltages in tube amps are much higher. In addtion the current requirements are far lower. Caps are also used for ripple reduction an .......
485: Dynaco-Doctor Forum, What does a pair of 1N4007 diodes cost? (0.00)
Posted by Russ57 on 2008-11-02, 05:10:20 (208.60.249.93)
I just went through this with a guy on vintage. At the risk of repeating myself I'll make the following points. 1) The price is silly for what you get. If someone can't solder a couple of diodes in pl .......
486: High Efficiency Speaker Asylum, Not only do I have those wire nuts... (0.00)
Posted by Russ57 on 2008-11-01, 16:14:51 (209.214.0.80)
I think I have the same speaker wire. I wanted a pair of those bowties but the guy wouldn't sell them without the bass cab. I'll have to start looking on epay, 25 bucks is a nice price:) How low will .......
487: Tube DIY Asylum, Okay (0.00)
Posted by Russ57 on 2008-10-31, 06:25:55 (72.46.240.196)
Hello Henry, it is nice to see you posting. I can own being wishy-washy. Of course I prefer to see it as being diplomatic but your point is taken. You are right; the forum is dumbed-down. It pisses me .......
488: Vintage Asylum, I'll see if I can post a pic (0.00)
Posted by Russ57 on 2008-10-30, 09:00:51 (72.46.240.196)
Notice the logo? Some call it a winged C. Svetlana name is owned by someone else. The tubes are called SED now but the logo remains the same. Russ .......
489: Vintage Asylum, FWIW (0.00)
Posted by Russ57 on 2008-10-30, 07:58:12 (72.46.240.196)
IMHO the EH EL34's have a hotter top end as in more treble. I like them. The "flying c" EL34's are well rounded and well built. I'd advise most to start with them. The 6CA7 has a reputation for strong .......
490: Vintage Asylum, Okay, next round of tests (0.00)
Posted by Russ57 on 2008-10-30, 05:42:25 (72.46.240.196)
First i'll say I don't trust JJ brand tubes:) I don't know what your KT77's are. Okay, aside from a bad tube the most common reason for your problems are tube sockets and bias supply. 1) Over time the .......
491: Vintage Asylum, Try the following (0.00)
Posted by Russ57 on 2008-10-29, 11:44:37 (209.214.0.80)
1) Remove all tubes and replace fuse with a fast blow 1 amp. Then turn the amp on and see if the fuse blows. It shouldn't. 2) Put the normal fuse back in and just the 5AR4. If the fuse blows it is eit .......
492: Tube DIY Asylum, You know what is pathetic about all of this? (0.00)
Posted by Russ57 on 2008-10-28, 20:01:39 (209.214.1.160)
I may have this all wrong and maybe a lot of folks only want to make fun of the situation. Instead, I have decided to feel that there are many who want to give this concept a fair shake but can't get .......
493: Tube DIY Asylum, Stephen (0.00)
Posted by Russ57 on 2008-10-24, 12:13:26 (72.46.240.196)
He did give you an explanation. He said, "Run the standard 'defeat placebo' testing and see if there is a real difference found. Do please report back in full." "Defeat placebo" could be double blind .......
494: Tube DIY Asylum, Eupen (0.00)
Posted by Russ57 on 2008-10-24, 04:57:04 (72.46.240.196)
Hey Mitch, When you get time look into Eupen's offerings. You know I am not a fan of magic wire. I feel their stuff is worth looking into. A certain company rebrands their stuff and sells it for stup .......
495: Tweakers' Asylum, If you want to be legal (0.00)
Posted by Russ57 on 2008-10-24, 04:42:34 (72.46.240.196)
Code (in most areas anyway) requires you to pigtail. What this means is you use wire nuts to connect the entering and leaving wiring together along with a short piece that goes to an outlet. This way .......
496: Tube DIY Asylum, have you tried them? (0.00)
Posted by Russ57 on 2008-10-23, 08:43:49 (72.46.240.196)
I have a friend who swears by the rikens. I'm too cheap to try them. I didn't care for the kiwame when I tried them. Huntington are worth a try. The 5 watters are mills under another name if you ask m .......
497: Vintage Asylum, Maybe one from a microwave???(nt) (0.00)
Posted by Russ57 on 2008-10-21, 08:13:30 (72.46.240.196)
. .......
498: Vintage Asylum, 40 or 50 caps isn't that many (0.00)
Posted by Russ57 on 2008-10-17, 20:13:15 (209.214.17.149)
I started off thinking like you, all I need is enough for what I now own. A few years later I have rebuilt several items and would have come out ahead if I went ahead and bought a quantity. Add in the .......
499: Tube DIY Asylum, I thought you were talking about a CCS:) (0.00)
Posted by Russ57 on 2008-10-15, 16:49:28 (209.214.16.200)
No, I wouldn't put all 12 tubes in series for a lot of different reasons. Mark Kelly has posted some good stuff with regards to CCS's and a combination of voltage and current regulation. I agree with .......
500: Tube DIY Asylum, What do you make of... (0.00)
Posted by Russ57 on 2008-10-14, 17:08:42 (209.214.20.85)
G2 resistors on only half the tubes? Given what else I see in the schematic it is hard to buy it was a "cost cutting measure". I could see a lot of little things to do. Looks like a fun project. I alw .......
Found total of 500 records, Query: , Author: Russ57 in All Forums, Time: 2 sec.