DC-2 + Preamp problems

[AllNothing]

Hi guys, I'm new here.

I have a Mesa Boogie DC-2 Studio Caliber.
I love its sound but I also want a different one... and I bought a marshall preamp.

I use it in this way:

Guitar-> Marshall Preamp -> Return of DC-2 (with FX MIX at 100%)
so it skips the DC-2 preamp.

It works fine, but sometimes the sound gets a lot brighter for a few seconds, then the normal sound comes back.

Maybe there's a better way to use the preamp and to skip the DC-2 preamp.. bur I don't know how.

Can somebody help me ?

Sorry for bad english, I'm Italian.

 

[blutac]

Hi

the effects return on my DC-3 is having problems too

if i plug my effects box (GT8) in it sounds great then the volume levels drop and then it goes back to normal.

i've replaced all the tubes and it's still doing it, could it be a dodgy connection ?

any advice

cheers Dave

 

[AllNothing]

A friend of mine told me that the problem should be the electric tension, which must be constant. When there are peaks of tension, the amplifier sounds louder and brighter.
In fact, to me the problem only happened with storms outside...