Traynor YCV40 Standby switch problem

Standby switch not working on this amp. I investigated but could not fix economically. Wirth watching though.

[@alexdeleon7135]

All things considered, this was still a successful episode. It informs any owners, or future buyers of this particular model Traynor of what to expect as a common defect of their design. Although the owner decided against a repair, I hope you at least charged a bench fee. The time it took to disassemble ,and research a schematic took time; which in turn has value. Stay safe, and healthy, Stuart. Cheers!

[@stuartukguitarampguy5830]

Thanks Alex. Yes I chrged a modest amount and also for a new valve of course. Happy Christmas!

[@ThomasACarlos]

I rebuilt a YCV80. The Standby circuitry is a mess, no doubt about it. The button triggers an opto coupler device that does two things. It changes the lamp color between red and yellow (which is two small LED devices in the jewel cover) and then biases up a circuit that turns on the FET. Part of this circuity is a string of 5 (or so) zener devices. If someone really wants the standby to work properly, ditch this circuit, install a regular ole DPDT switch, run two wires to the outer edges of where the FET resides (removing the FET of course), and then add small LED to indicate the amp HT is connected and the amp is on. You will want to figure out how to make the Red indicator stay on when you apply the power button.

[@stuartukguitarampguy5830]

Hi Thomas. That's crazily over complicated for what it does!

[@rockettcrawford890]

I've just recently discovered your channel and I just love it. I'm making my way through all of your videos. I find your combination of experience, skill and honesty about it all makes your videos fun. I also like that you don't give away the endings in your titles like some. I enjoy your "who done its" finding out in the end what was going on. I enjoyed this video just as much as the others. Thank you from Texas.

[@stuartukguitarampguy5830]

Awesome I;m pleased you like it. Thanks for the very useful feedback.

[@michaelevans3852]

Stuart, I thought it was a successful video. I'm sure there are many times the customer will opt to not spend money on something like this. Good to know it happens. It's also nice to see the inside on another amp we haven't looked at before. Thanks for another good show.

[@stuartukguitarampguy5830]

Thanks Michael.

[@richwallace6854]

I think Traynor reccommends changing ALL the active components in the stand-by circuit. the FET, Opto-coupler, I think there's a transistor, and whatever. I don't think any Zeners were involved. They probably offer a kit you can buy.

[@williamgombert7710]

Once again, very intresting Stuart!!! Let me also wish you all the best for 2022! Hope to see a lot of your video's

[@stuartukguitarampguy5830]

Thanks William!

[@3MonkeysGarage]

Merry Christmas Stu. I hope you are having a great year and a better one next year

[@stuartukguitarampguy5830]

Many thanks! Have a great Christmas yourself.

[@edwardhannigan6324]

Very informative Stuart, but time is money as they say and you're right about the cost of repair compared to it's worth as an amp. Nice one..! Ed..uk..😀 Happy Xmas..!

[@stuartukguitarampguy5830]

Thanks Ed Merry Christmas!

[@Pentode3000]

If the amp comes back one day try changing the optocoupler U3 4N35 as it shuts off the gate of the fet in combination with the standby switch.

[@stuartukguitarampguy5830]

Ah, interesting. Thanks I will.

[@rgbplumbinghilton]

Merry Christmas Stuart

[@stuartukguitarampguy5830]

Cheers Richard!

[@kedsinger67]

The one I have on my bench doesn’t have the feta. They probably corrected the problem. Love your vid though. I’m in the US.

[@stevehead365]

Hi Stuart, I hope you had a pleasant break. MOSFETs are extremely static sensitive, one false move and they will be damaged, only to bite your bum sometime later, they are sneaky like that. JFETS are almost as tricky. MOSFETS also tend to fail short circuit which caused the end of a friend's Fender Passport system, both sets of speakers blown and then the power supply, RIP, distinct lack of fuses. The original Traynors were built with maintenance in mind but since the owner died....... Happy new year.

[@stuartukguitarampguy5830]

Hi Steve. Ok thanks for that. Happy New Year to you as well.

[@goodun2974]

Perhaps when the tube lost vacuum and burned up, it either drew too much current and damaged the electronic high-voltage switching, or the loss of one working tube meant that current draw was halved and so the unregulated H-T voltage soared and damaged the switching circuit. BTW, Traynor are an old and venerable Canadian company that used to build very rugged hand-built amps (a few were purportedly tested by dropping them from the factory roof!) but I dont know who owns them now and these days they use PCB construction like everybody else.

[@stuartukguitarampguy5830]

Interesting thanks. Yes you may be right about that valve.

[@MrOlion]

I thought the same thing (one damaged tube and one damaged MOSFET). Stuart, while you had the amp open, were you able to measure the transistor you initially suspected? I understand that some Traynor amps have an auto-biasing circuit in them. Could it be that the section you were looking at controls the bias? I recently bought a very similar amp and wanted to do some research on it. Great content. Cheers for the video!

[@stuartukguitarampguy5830]

@@MrOlion It's been a while since I did this and alas I cannot remember. Sorry.

[@zbaby82]

Happy Christmas Stuart.

[@stuartukguitarampguy5830]

Thanks Zack, have a good one!

[@kedsinger67]

Also, I can’t believe the customer was playing with one valve working lol

[@richwallace6854]

I bought oe of these amps new, back in the early 2000's. I never liked it. I was some how informed of it needing a "mod". Had that taken care of and had all the tube replace with something better. It sounded O.K., but still nothing really GOOD. I thought of changing the Celestion. but for a $329 amp,I'd rather just sell it.

[@stuartukguitarampguy5830]

Hi Rich. Yes I don't really like these amps much.

[@TheEricsnet1]

Merry Christmas!

[@stuartukguitarampguy5830]

Many thanks, I hope you have a great one.

[@tjsogmc]

Interesting. I wonder if the complexity of the circuit is there just as a red herring in case somebody wants to reverse engineer the amp? It wouldn't surprise me if that was the case.

[@stuartukguitarampguy5830]

Hi. No I doubt it, they have better things to do! I always laugh at these companies who refuse to hand out schematics, as though that would protect them against someone seriously wanting to steal the design.

[@montygore]

Your a cool guy Stuart.

[@stuartukguitarampguy5830]

Cheers Monty!

[@rhysmorgan6192]

Hi Stuart. I sent you a mail a few weeks/months ago on the recommendation of Mark Silk about my vintage early 70’s Traynor YGL-3. It could do with a general service but also would like to know if it’s possible to add an fx loop. I wonder if my mail made it to you? I’m just outside Newbury so pretty close to you. Regards, Rhys

[@stuartukguitarampguy5830]

Hi Rhys I don;t recall getting that. Anyway, I don't do things like add FX loops as it can take hours and also not work for various reasons. Sorry.

[@andrewdenine1685]

Traynor website for the schematic of the ycv series

[@Mark-ry3ij]

I have the same exact amp but i sold it coz the fuse keeps blowing. I didn't bother fixing it because of the hassle to open it 😅

[@stuartukguitarampguy5830]

Interesting thanks Mark.

[@jernejkurincic9050]

There is a suspiciously high number of "thermally cut" power tube envelopes in your videos. Bad batch of tubes in some local shop?

[@stuartukguitarampguy5830]

Didn't quite understand that. What did you mean by 'thermally cut'?

[@jernejkurincic9050]

@@stuartukguitarampguy5830 Yes, I put it awkwardly, sorry ...The way cracks appear on those tubes looks like when you cut a bottle in half with a hot wire. I kept thinking what could be wrong with those JJs to fail on 100W Marshalls.

[@stuartukguitarampguy5830]

@@jernejkurincic9050 I think it's just a plate voltage problem. Although they SAY it can take 600V+ some fail at about 450V and arc over.

[@kedsinger67]

I meant to say FET

[@stuartukguitarampguy5830]

Got that thanks.

[@lesliel1182]

Dioxit