Volume drop off when using effects loop

i know I read about this issue here before. But, I cannot find it in a search...

When using the effects loop on my DR3Ch (2011), the volume will drop to almost zero... Then after a few seconds... it will come back up.

My feeble memory recalls that it must be a preamp tube (at V4 or V5??). Should I crack it open an start rolling tubes? Or is it likely another issue at play here?

This one still has the stock tubes in it. But, I have a nice assortment of 12AX7's (Tungsol, phillips, and Russians) to play with.

Cheers

search for cathode follower on this board

Thanks, I will do that straight away.

pokerrules47 said:

search for cathode follower on this board

Click to expand...

Here you go

http://www.forum.grailtone.com/viewtopic.php?f=4&t=25102&start=19

Dom

did you get to solve your amp problem?

mine started to have this problem today... i was going to test a chorus pedal when out of the sudden the volumen dropped big time...i thought it was a cable so i change it... went on standby and connect directly to the amp... ufff same issue... then i started to toggle the switches in the channel strips.
when i notice that this problem came from the FX on/off switch...

so i started freak out... really freak out... i knew for a minute that it had to be a tube problem but them again i couldn't search for the issue online and in here...

so after this post and the link Dom gave... i'm feeling a bit cooler but then again... i have to buy preamp tubes...

ironjose said:

did you get to solve your amp problem?

Click to expand...

Yes and no actually.

It's been a while waiting for an assortment of new tubes to arrive via post from several stateside vendors (I even got some TungSol 5U4Gs to try out later)... I have inserted the suggested chinese pre-amp tubes (GT chinese). And, rolled through several combinations of the others.

Right now, I have this...
V1- TungSol
V2- Mullard
V3 and V4 - Groove Tube Chinese
Edit <I also tried JJs in V3 and V4>

(I also have a quantity of EH and JJs and Sovteks still available if needed.)

While this config does correct the volume drop off from the effects loop. This particular configuration has spawned other problems with tone in general and channel 3 in particular. The tone is really weak on CH3 - much weaker than CH2 with the same settings. Both channels seem to have been de-nutted compared to the stock tubes... And, the volume rolls up and down on CH3 when using effects in front of the amp. CH1 however, it absolutely SCHWEET! especially when pushed.

I haven't had time to sort out the proper combinations of the other tubes I have. At some point I will post back the details of my eventual success... or my complete surrender in just putting the stock mesa tubes in with a couple of mesa chinese in V3 and V4.