Trem-o-verb lossing gain.

[metalmarlon]

So it seems that the trem-o-verb that I got is having gain loss over all the channels and modes.

It was great at first, then after a while of playing (about 15-30min) the gain would drop. It is kind of like having a Marshall JCM800 that is boosted and and then taking the boost off.

OK... maybe not that extreme, but close.

Well... now it seems to have become permanent.

Any ideas? From what I have read it does not sound like it is the LDRs. But I don't know.

I am going to call Mesa tomorrow.

 

[rectofried]

i have a 96 recto that was doinmg what u describe as well as volume loss/harsh sound..got a clean bill from a tech, swapped chinese tubes in v3/v4 and problem went away for awhile..went to practice tonight and pushed amp hard, same crap again. im at wits end. i have had amps with intermittent problems in the past and never found a tech that could fix them.. even mesa could never fix the last 2 channel recto i had that did the exact same thing..volume and gain loss. im saving cash to get the entire amp redone,thats all i know to do.. im gonna send it to andy when he gets moved. maybe he can do something with it. im about ready to sit it out in the yard and put 30 rounds of ak-47 ammo in it.

 

[metalmarlon]

Ouch!!! That sucks.

Also, I forgot to add. I replaced all the preamp tubes and still have the same problem.

It is not a volume drop, just a loss of gain and some treble.

 

[rectofried]

yep, sounds like somebody threw a blanket over the cab and gain goes out the window..lucky i have another 2 channel that is jam up.

 

[mikey383]

There are two things you can do.

1. Replace all the tubes. Preamp, power, rectifier if you're using them...if you're not, then don't worry about them.

2. Take it to a reputable tech.

From what you describe, it either sounds like you have a bad tube, or there is a cold solder joint somewhere. Being a TOV, you may have a bad LDR. Send it to Mesa, and they will upgrade them for a minimal fee.

 

[metalmarlon]

There are two things you can do.

1. Replace all the tubes. Preamp, power, rectifier if you're using them...if you're not, then don't worry about them.

2. Take it to a reputable tech.

From what you describe, it either sounds like you have a bad tube, or there is a cold solder joint somewhere. Being a TOV, you may have a bad LDR. Send it to Mesa, and they will upgrade them for a minimal fee.

I did replace all the pretubes and I don't use the rectifiers. So all that it could be is the power tubes. I just have a gut felling that they are not the problem.

So it look #2 for me. Cold solder joint is probably the problem. The preamp board was loose when I got it. I had to replace v1 to get sound out of it. It was not the pretube itself because I put the old one back in and it was fine.

I looked at the guts to see if I could visually see something wrong. I could not see anything though.

 

[94Tremoverb]

It sounds like you've tested most of it anyway, but for anyone else with a Tremoverb with the same sort of problems, here's what to do before you spend any money on more tubes or take it anywhere:

First select Silicon Diode rectifier on the back panel. Now test the amp - if the problem persists, it's not the rectifier tubes which are completely out of the circuit when not selected (on this amp and the 2-channel Dual Rectifier, 3-channels are different).

Now remove one pair of power tubes - either the inner or the outer pair. Connect the speakers/cab to the jack for *half* the correct impedance, eg 4 ohms for the combo version with its 8-ohm (2x 16-ohm speaker) load. Now test the amp. If it's still showing the problem, it's not the two tubes you've pulled, so put them back and pull the other pair instead. Test again. If it does it no matter which pair of power tubes is in, it's not a power tube issue.

Now, select Bypass with the FX loop switch in the back (not the footswitch, if you're using one). If it still does it, it's not V4 so you can use this as a spare to test the other five positions in sequence, checking each time. V4 is the one furthest from the input jack in the row of four at the front of the amp.

If after all that the problem is still present, it's not a tube problem!

 

[metalmarlon]

It sounds like you've tested most of it anyway, but for anyone else with a Tremoverb with the same sort of problems, here's what to do before you spend any money on more tubes or take it anywhere:

First select Silicon Diode rectifier on the back panel. Now test the amp - if the problem persists, it's not the rectifier tubes which are completely out of the circuit when not selected (on this amp and the 2-channel Dual Rectifier, 3-channels are different).

Now remove one pair of power tubes - either the inner or the outer pair. Connect the speakers/cab to the jack for *half* the correct impedance, eg 4 ohms for the combo version with its 8-ohm (2x 16-ohm speaker) load. Now test the amp. If it's still showing the problem, it's not the two tubes you've pulled, so put them back and pull the other pair instead. Test again. If it does it no matter which pair of power tubes is in, it's not a power tube issue.

Now, select Bypass with the FX loop switch in the back (not the footswitch, if you're using one). If it still does it, it's not V4 so you can use this as a spare to test the other five positions in sequence, checking each time. V4 is the one furthest from the input jack in the row of four at the front of the amp.

If after all that the problem is still present, it's not a tube problem!

Wish you would have posted this earlier. LOL!!!

Just took it to a local Mesa repair place. The guy said that it is probably the LDRs. And the Mesa factory told me that there is a LDR/resitor update for my series of Trem-o-verbs. So we will see.

The guy that I took it too seems to be really on top of the issues with Trem-o-verbs. So I'm sure he will fix it.