Purchased completely gone-through '72 Traynor YBA-1 - DOA

[CherryFive]

I just won this auction here, assuming the amp would come in working. Unfortunately it arrived and while it powers on, the sound coming out is extremely quiet. The volume knobs need to be cranked to ten, and you can barely hear sound coming out, and it's clipped and weak/ ugly sounding. As you can see by the auction, lots of components were replaced and the power tubes new.

http://www.ebay.com/itm/Traynor-YBA-1-B ... 3aa3a4f3d4

Work Preformed:
All potentiometers [pots] removed, disassembled, cleaned, re-tensioned, re-lubed, and treated with 100% Deozit then reinstalled
Replaced all Diodes
All electrolytic capacitors replaced and upgraded
Replaced ceramic capacitor with mica cap
Replaced all foil filter capacitors with polypropylene Illinois capacitors
Replaced all old resistors with matched carbon resistors
All tube sockets cleaned and treated
Chassis cleaned and polished
Ground power cord added

The three 12AX7s are tung-sol USA made tubes
Two new matched Russian made electro-harmonix EL34EH tubes that are very similar in design and sound of the old German RFT Siemens tubes of the 60s and 70s with same dimple-top bottle larger base and almost same construction

I'm prepared to take this amp to my tech Larry and see if he can figure it out. I just don't feel like dealing with returning and waiting. Rather just get this thing fixed asap. But let me ask you, what do you think would cause such a failure? I replaced the three- pre -amp tubes with others I had and the sound was still the same. Very quiet when cranked to ten. I know my speakers and cables are GOOD because I have a 1978 Music man head that works like a champ and tests perfect on this gear (1971 15" 8-ohm Electro voice).

I just want to know if this is something I can fix myself? money and time is always an issue. Thanks

[jelle]

Sounds like the output transformer

[CherryFive]

Really? no kidding? The buyer assured me it wasn't the transformers. What leads you to believe that? I am hearing a noise when I turn the amp on - it's like the transformer are buzzing like on old bogen tube amps.

[CherryFive]

Seller said the transformers were fine and he bench tested this thing for weeks? I just need some insight so I can decide what to do here. Whether to get a refund or just have a tech fix it.

[Richie]

make sure you are plugged into the speaker jack, and NOT the ext jack.

[CherryFive]

Through the speaker jack, I hear the signal faintly cranked to TEN! When I use the other "external speaker" jack guess what? A loud frightening sounding hum. I don't think that's normal? I'm not inexperienced to using vintage tube amps, but I'm inexperienced at troubleshooting that's for sure. All I can do is report what I found. I hate to do a refund but if this guy thinks the transformer is out, that's not good

[romberg]

If you were one of my friends I would advise you to send it back ASAP. But if you insist on keeping it then I'd take it to your tech. I think something went wrong in the "restoration" process. It may be a simple fix. But who knows the quality of the work that has been done. There are no images of the parts inside the chassis. The insides may be a mess.

Mike

[CherryFive]

Thanks Mike. Actually the images of the inside look beautiful! I even opened it and the work looks amazing:

[cbass]

Im sorry but that looks like pretty shoddy work to me. Probably a bad solder joint. Oh an those cap cans are junk

[danman]

Have you tried a new set of power tubes yet? It's possible that they could have been damaged during the shipping.

Edit...After reading your description of the sound through the output jacks, you may have bigger issues like the guys have mentioned.

[CherryFive]

No, I haven't tried a new set of power tubes, although I do have a set in my Music Man 1978. Should I pull them out and try it?

[R.G.]

I have to apologize first. I think I'm getting old and curmudgeon-ly.

It has started to amaze me how very many posts in amp forums say something very much like:
" My [insert amp here] is doing [insert symptom here]. Any idea what it could be?"
Very often the next sentence is"
"It's the output transformer going bad, isn't it?"

It is true that there are some few casues that can be diagnosed from that cryptic description, and almost none from the OT question.

I have likely contributed to this state of affairs by writing up "The Tube Amp Debugging Page" at geofex, although this is so long ago that probably few people go there any more.

But there are really very few conditions that a non-technically inclined person without at least a volt-ohm-meter can deal with. And the question "my amp is doing X, what could it possibly be?" is a huge indicator that the person asking is not technically adept enough to deal with it.

While it is fascinating to play a game of thousand-guesses about what it might be, the truth is it may be almost anything, from a bad jack to a broken wire, to a bum tube, to - yes, wait for it! - a bad output transformer. All of the guesses you get in the game will ultimately have to be checked out, and that's where you run into needing to do something skilled and technical, perhaps involving instruments, to find out if the guess is correct.

Again, I apologize if this sounds harsh. But I believe it's realistic. Unless you can do diving into a powered-on tube amp chassis with a meter and know what you're doing well enough to know you're going to come out alive, then the limits of what you can do to debug your own tube amp is to replug all the connectible things, including fuses, tubes, cords and speakers, and if that doesn't fix it, haul it into a competent tech. People with the necessary skills don't ask the questions this way.

I'm not putting you down. I'm just trying to keep you safe. There are really dangerous things lurking in the tube amp chassis. If you do have the skills, I apologize again, and ask again with more technical information for us to go on.

[Leo_Gnardo]

+1 for R.G.'s post ^^^ and I think jelle was just winding you up. You devil you.

Yes, I get lots of crustomers who whine about "it must be the transformer(s)". This speaks to a mindset implanted by those clever rogues at Mercury, masters of deceit. If there was bird poop on your car's windshield do you jump to the conclusion you need a new muffler, because there's so many muffler shop ads on TV? Gosh, a new engine or transmission, woe is me! No, address the problem, it often turns out to be simpler and cheaper to fix than you thought.

How about those pre tubes. Do you see two filaments glowing in each? There's a place to start. Doesn't happen often but it's about the easiest problem to fix. Don't ya know it, I had two amps cross my workbench last week with a filament out in a preamp tube. Fast. Easy. Cheap.

edit: Faint signal from the main speaker out, and lots o hum from the ext speaker out? That is bizarre. Makes me wonder if mister fixit swapped 'em around, and there's another problem besides. Yes I'd recommend bring it to your friendly local tech. Bet you half a donut it's not a transformer.

[Cameron]

Through the speaker jack, I hear the signal faintly cranked to TEN! When I use the other "external speaker" jack guess what? A loud frightening sounding hum. I don't think that's normal? I'm not inexperienced to using vintage tube amps, but I'm inexperienced at troubleshooting that's for sure. All I can do is report what I found. I hate to do a refund but if this guy thinks the transformer is out, that's not good

Check the wiring of those speaker Jack's. These days "amp tech" does not always mean ....good amp tech that can repair .....nowadays it means paint by numbers copy...not repair or fix..

[Teleguy61]

You spent $600 for an amp represented as working 100%, and you get it and not only does it not work, all original parts have been removed and shoddily replaced with commonly available parts?
And you don't think you should demand your money back?
This is a joke right?