Traynor YCV40 Clean Channel Issue

[twilightofthedogs]

Howdy folks, first post here on the Music Electronics Forum. I have a Traynor YCV40 that I have been doing righteous battle with for a while now and I can't figure it out. I have any angry buzz type sound that comes through on the clean channel only. It does not effect the signal, and the amp sounds quite nice if you can ignore the buzz. It does come and go as well. Sometimes it will go away for minutes at a time. The dirt channel does not seem to be affected. I have already checked all the easy stuff. It isn't the tubes, and I replaced the caps the 82uf/450v and 10uf/450v caps in the power supply. Any other ideas? I have attached a link to a video of the issue and a link to a PDF of the manual. Any ideas? Thanks!

Ycv40 - YouTube

http://www.traynoramps.com/downloads...an/smycv40.pdf

[Chuck H]

There is quite a bit of remote switching in that amp. That made me think it could be a failed switch. But since it's intermittent it's more likely a dirty contact. One that is only relevant to the clean channel. This could include any unsoldered cable connections or jack switch functions that are only used by the clean channel. It's that, abad relay contact or a cold solder joint.

[twilightofthedogs]

Thanks for the reply Chuck. Am i right in thinking that since it is not affected by the clean channel volume pot that the problem must exist somewhere in the small area between the volume pot and the place where the two channels come back together before the pre-amp out. The noise is present if I plug the preamp out (FX out) into another amp. My suspicion had been on cap 24, which couples the plate of v2b to the phase inverter. Anyway, this at least gives me an area of focus for next time I have the gumption to take the dang thing apart. I have to say, this is right up there as one of the least fun amps to work on. They layout makes testing with the amp on very tedious. Unless I am missing something clever they did. Anyway, thanks!

[Chuck H]

Am i right in thinking that since it is not affected by the clean channel volume pot that the problem must exist somewhere in the small area between the volume pot and the place where the two channels come back together before the pre-amp out.

That sounds right.

My suspicion had been on cap 24, which couples the plate of v2b to the phase inverter.

I don't think it's that cap. The symptoms are wrong for a bad cap in that position. It's probably a bad volume pot or the volume pots ground connection, a dirty contact (are there ribbon cables?), cracked solder at a tube socket or a dirty socket pin contact. Have you tried giving it a whack to see if there's a mechanical reaction? Wiggle the volume knob, ball up your hand and thump the top of the amp, wiggle the clean channel preamp tubes a little in their sockets. Any noises?

[dranem]

Hi,
I know it has been a few years since you posted that problem but I have a problem similar to the one you described in your post. Where you able to solve the problem?
My YCV40WR shows additionnal symptoms: the buzz is present on both channels and when I lightly tap on the controls (any of them, including the switches) I hear the tapping in the speaker.
The other symptoms are similar. I have resoldered everything but the problem is still there, however the sound does not go away anymore and the buzz is less important.
Any hints?
Thanks

[Chuck H]

Piggybacking a post is "ok". It's become generally accepted because of it's frequency. Learning to navigate the forum and starting a new thread is better.

If tapping or whacking the amp makes a noise like a microphone (you can hear an accurate audio representation of the noise you created) the problem is a microphonic tube. If the noise from tapping or whacking is more of a crackle, pop or otherwise unrelated noise the problem is most likely a bad connection or a dirty, non soldered contact (like a jack, switching jack, switch, pot wiper ,dirty tube pins or sockets) or an intermittent fault in the hard wiring (cracked trace or solder contact or a cold solder joint). Unless the problem is microphonic power tubes, in which case the noise would be a sort of grunt or PFFfft, sound. You get use to the different noises when you hear them a lot

[twilightofthedogs]

Alas, I never did figure this one out. Kinda lost interest then sold it to a guy (for cheap) who didn't mind the buzz. Here's to guys who don't mind the buzz!