I usually play around home, and when the Traynor was on, there was typically a bit of white noise coming from it. It was NOT the case that it sounded like something was "wrong" with it. Rather, the noise floor was a little higher than I liked --- higher than the Peavey Classic 30 it replaced --- although I felt like I might be being picky. I sent it to the main Traynor U.S. service center, and they told me that this was a common observation, and that it was due to the pre-amp design. I guess that pre-amp tubes are always "full on" or something like that, and the clean channel volume just determines how much signal to let through. Hence the noise level didn't change much as you turned up the clean volume.
Anyway, they did what they said was a very common mod for this amp, and put in the overall master volume. They also put a special "master" label sticker over the presence knob label. They told me the mod was easily reversible. They said that the presence pot is still inside the chassis and in the circuit, but it is locked down on "5." I never looked at it. It seemed like it was something I could have reversed myself, but I of course can't take any responsibility for anyone else opening it up and modifying it, especially if you haven't worked on tube amps before. Be very careful if you do so, and read all the stuff out there about draining caps. Shouldn't be a problem on a modern amp with bleeder resistors, but it's best to be safe.
Honestly, the presence control isn't vital on this amp, to my ears anyway. It wasn't a major part of the overall tone control like it is on, say, a vintage Plexi. Perhaps that's why there is an overall master but not a presence on the YCV50. Also, if you DO end up switching the control back to a presence control, because the noise comes from the pre-amp, you can kill it by putting a noise suppressor pedal in the effects loop. I tried this with a NS-2, and it certainly did take care of the issue.
I recently got a Mesa Express 5:25, and I also tried out a Rivera R55 here for a while. By comparison, with the master volumes on the clean channels turned up all the way up, each of those amps is noisier than the stock YCV40. Just didn't want to give the impression that it's ridiculously noisy or anything --- I'm just picky.
