Ampeg SVT-IIP preamp problem

[BassPlayer3187]

I recently received an Ampeg SVT-IIP preamp and have began to incorporate it into my setup. I love the tone I get from the tube preamp and everything sounds great, most of the time. The preamp begins to overdrive and distort the signal after running for a few minutes. This problem seems to come and go as I play through it. I have taken it apart and cleaned the inside and still have the same problem. Has anyone else had this issue with these preamps? Does anyone know what could be causing this or how to fix it to be more reliable? Thank you!

[RickenBoogie]

How are you using it, and with what other gear?

[BassPlayer3187]

I've tried it both directly between the bass and the input as well as running the preamp through my effects loop. I also used several different basses and amps with it, but mainly am using my GK700rb-II with a GK 4x10 and my fender jazz bass.

(is that what you meant by how am I using it?)

Originally Posted by RickenBoogie

How are you using it, and with what other gear?

[RickenBoogie]

So, do you have the same problem either way you hook it up? Putting it "in line" or between the bass and main amp input, CAN overload the GK's preamp, but going in through the effects return should NOT.

[BassPlayer3187]

yes i have the same problem either way. That is what I figured which is why I've tried it both ways, but I usually have it hooked up through the effects loop. Also it happens with other amps as wells (both combos and stacks). This is why I'm confused...

[MIJ-VI]

Ampeg SVT-IIP schematic?
Ampeg SVT-IIP schematic?

SVT-IIP Bass Amplifier Owner's Reference Guide SVT
http://www.ampeg.com/pdf/SVTIIP.pdf

[BassPlayer3187]

Thank you, I had found the Owner's Reference Guide and that was no help. Hopefully this schematic will be!

Originally Posted by MIJ-VI

Ampeg SVT-IIP schematic?
Ampeg SVT-IIP schematic?

SVT-IIP Bass Amplifier Owner's Reference Guide SVT
http://www.ampeg.com/pdf/SVTIIP.pdf