Mesa Tremoverb intermitent issue. HELP!

[Leroy Crow]

Hello everyone,

I recently purchased a mesa tremoverb a couple of months ago. It sounds great and all seemed to be good with it (at least for the first week or so) then out of no where I started to get a strange sound from it. It only seems to happen at higher volume levels like those when using in a full band setting, and not at practice/bedroom volumes. What happens is I get a strange warbling sound, most noticeable when you have the gain at moderate levels about half way or so on vintage/modern and maybe 3/4 or so on blues. It does it too on clean but it isn't as bad. It sounds almost like a chorus effect with the depth and speed turned all the way up, like a bad modulation effect. It comes and goes and works properly more than it messes up probably 99% of the time. I have also had a couple of times where it sounded really weak and distorted even on clean when it should sound crystal clear. I have since replaced all the preamp tubes, and put all new power tubes in, I have a new set of EL34 and 6L6s tried both. When it is doing it I have tried every possible variable, switched every switch, knob, and output. And it has done it after just warming up and after several hours of playing with no problems. Very strange I know. I had a guy look at it but he didn't want to open it up without hearing the issue and of course it never did it when I left it with him. Im probably going to end up leaving it with him until he hears it do it and can hopefully figure it out. In the mean time I figured I would post on here and see if anyone had any possible ideas about what this could be. I realize Im probably going to have quite a difficult time with this one so and input any one has would be greatly appreciated. thanks.

 

[mandoismetal]

The only thing I could think of, since you already mentioned that you've replaced all the tubes across the board, is maybe an out of phase effect in the loop?

This used to happen to me when playing with my ROV with a delay in the loop. Luckily my pedal had a kill-dry feature.

I hope you get this sorted out!

 

[Leroy Crow]

Yeah when it has done it i have unplugged everything and just went in straight guitar no effects in the loop or in front of amp. I've even tried unplugging the reverb unit and still it will do it....

 

[mandoismetal]

I'm sorry to hear that, man.

I would probably phone Mesa. They probably know about it. It won't be cheap if you end up deciding to have them check it.

Shipping lone would be at least a couple of hundred.

Best of luck!

 

[Leroy Crow]

Update for those who care or for anyone else with similar concerns. A quick note before I explain what it ended up being, I have been a player for over 20 years and have never seen this before. Also the the tech that ended up figuring it out has probably 30+ years in repairs alone and he said he never saw anything like it before either. Also I felt kind of dumb for not being more thorough with my own trouble shooting before taking it in but I guess it was worth paying the 60$ to have the whole amp gone over and have the problem finally figured out....so enough with my ramble and on with the cause....DUMBROLL please........it was the friggin speakers!!!! I feel like such a dummy for not trying to plug in a different cab but I have never seen/heard anything like it! Apparently the speakers were just sooooo worn that they were actually producing extra oscillations in there causing extra sound, it sounded like a crappy modulation effect, wierd. At least that's the best explanation my tech could come up with...as he said he had never seen a speaker do it either. I had a bit of trouble believing it for myself but plugged into my 4x12 mesa cab sounds perfect. But this amp is almost 20 years old and two vintage thirties can handle the power of the DR TOV (barley) apparently they were just worn to the point of no return.... Anyways just wanted to update cause I found this quite interesting/puzzling

Also one other note, as far as the intermittent nature of the problem, not really sure why it was worse sometimes more than others...but it definitely seemed to eventually get more consistent and pronounced as time went on, one reason why I think I finally was able to get it figured out cause when it started it didn't do often, maybe temperature and humidity playe a role I'm sure there are many variables at play here....hopefully someone will take something valuable away with this one I know I sure did

 

[Leroy Crow]

Dang! I just realized I never really ever mentioned that it is/was (speakers removed at the moment) a 2x12 combo....hard to get help when I never fully disclosed all the details.