Traynor YGM3 issues

[JohnHunsucker]

I just acquired a used YGM3. Great amp but I'm having a couple of issues:

1. Reverb/Tremolo are both making "popping" noises.
2. The volume knob won't lock into place, it rotates continuously both left and right, in effect - causing the volume to fluctuate.

If anyone has any person experience with these amps or any knowledge of these problems, please give me some suggestions.
I'd rather fix the problems myself than take them to a tech. Thanks.

 

[cugel]

well first get a new volume pot and it looks like a 1Meg audio taper will do the job. alphas are cheap but i like cts. Of course for the other issues, swapping v5 and/or v6 with tube you know is good is a start, but i doubt thats it. If the amp is original then it will need a cap job: replace the electrolytic caps in the power section. Look at them and see if any are bulging or leaking (i think it uses cap cans so that might not be do-able), including c21. Check the power resistors too: R38-R41, which is a piece of cake.

an answer to your prayers (the guy has multiple vids):

 

[JohnHunsucker]

Thanks for the reply, I will definitely be changing out the volume pots. Do you think that would solve the problem of the continuous spinning?
As far as v5/v6 - I'm buying new preamp tubes to go in so maybe that will address the issue but I'm not banking on it. I just dated it to be a 1970, almost positive all of the caps/resistors are original. By electrolytic caps in the power section, do you mean the filter caps? If so, I am in the process of changing those out for F&T 32uf can capacitors (blue ones with clamps used in Marshalls) at the suggestion of mister Pat Farlun from that video and also a previous post. How would I go about checking the resistors you suggested? I'm sorry if I come off as oblivious, this is my first time ever doing any sort of amp modifications or repairs.

 

[cugel]

if its your first time, take it to a tech would be my advice. sorry to be so negative. But if you don't know how to check a resistor for resistance you could kill yourself repairing an amp! We don't want that!!

 

[JohnHunsucker]

Yeah, I mean.. Once the filter capacitors are completely bled and the DC multi meter reads them at less than a volt - would those resistors still contain voltage? I was under the impression that the amp would be safe after the filter caps are discharged and verified.

 

[xtian]

Correct, once the electrolytics are empty of voltage, you're good to go. Remember to drain the caps with standby switch (if there is one) in RUN position, so it's not isolating the reservoir cap(s) from the circuit.

No, resistors cannot store charge by themselves.

 

[cugel]

What I mean is that, if you are going to fix that amp and have it working properly, you will most likely need to have the amp ON and look at voltages etc.
how else can you measure B+ voltages, determine the bias of the power tubes etc?
maybe you can just solder the parts in and be good to go.

 

[JohnHunsucker]

For the ygm3, how exactly would I go about discharging the filter caps properly? I've seen video tutorials doing it draining from the negative end of the capacitor and then checking the voltage but also have read that you can hook one end of the alligator clips to ground and then the other to the V1 pin and drain them that way? It's kind of ambiguous and frustrating not being able to find concrete answers but I guess it is what it is.

 

[JohnHunsucker]

Cugel, I appreciate the suggestions but I'm confident in my attention to detail enough to figure this out without killing myself or having to hire someone else to do it for me. All I need is the information to gather myself a makeshift SOP. How do I check for voltages on these resistors if it's on? I would assume finding their placement and location is relative to the schematic. But what exactly am I looking for? Are each of the resistors supposed to be outputting a specific voltage

 

[revbb63]

hope a question isn't out of place here...
i love my ygm3 1969 at 45 yrs old it's starting to pop and click and hum. 3 days ago the reverb went from long to short and yesterday the tremolo went dead with a "pop"! it's near stock, been re-tubed of course, the nasty presence cap removed, i put in a V-30 speaker and if you think they are heavy with the marsland (a 2.5 lb spkr haha), well..back off n all get a hand-truck for this sucker.
No cap job ever on it and with my limited knowledge i figure that is probably something that needs doing, as well as what's going on in the rev/trem part of the doohickey.
I need to order the parts myself, so i know what to get for the cap cans but what else would be up for a change after all these years?
please any help much appreciated

 

[axpro]

Hey Revbb63,

Your amp might be fine to be honest. Reverb problems may need a tank repair or a new tank, Going from "long to short" makes me think maybe you lost a spring, or got a short. Tremolo, I thought all the YGM3's were bias oscillating tremolo. Aside from the tube, I don't know much about that one... There wouldn't be a fender type "Tremolo Bug" in there, so you'll have to trace down the problem. As for what most likely needs changing, the power supply (caps and Resistors) most likely, after that you get a little iffy, since changing out ALL the caps would change the amps sound. not necessarily good or bad, but different.

 

[revbb63]

Hey Revbb63,

Your amp might be fine to be honest. Reverb problems may need a tank repair or a new tank, Going from "long to short" makes me think maybe you lost a spring, or got a short. Tremolo, I thought all the YGM3's were bias oscillating tremolo. Aside from the tube, I don't know much about that one... There wouldn't be a fender type "Tremolo Bug" in there, so you'll have to trace down the problem. As for what most likely needs changing, the power supply (caps and Resistors) most likely, after that you get a little iffy, since changing out ALL the caps would change the amps sound. not necessarily good or bad, but different.

Thanks axpro. i like to learn. i fixed the trem with a retube! the reverb hums still and the volume is JUMPING from soft to loud. i'm taking this to a repairman pronto
Best wishes on that guitar collection!!