Buzz appears after a couple of hours playing...

[KimGT99]

Hi there.
Since the buzz comes right of the cab, I'll post my question here...

After a +/- 2 hours of playing, I get an annoying buzz which also causes my tuner to display a constant "G" in the display. The buzz also alters the tone generally.

Here's my current setup:
Bass > Rocktron patchmate loop 8 > Ibanez TS9B > MXR Black label chorus > Boss BF-2 > MXR Carbon copy > EHX Micro Pog > Ampeg SVT 2 pro (Korg DTR in Ampeg tuner in/out)> cab.

Here's what I've done so far:
- switched the amp off > still a constant G in the tuner display , so the buzz is still there
- changed all the cables > still buzz
- switched off all stompboxes > yep, buddy buzz still hangs around
- went directly through the amp > no buzz, but altered, thin slightly distorted tone...

I didn't have the impression that one of the devices is exposed to heat (Ampeg is 4 he under the next device).

What I don't understand is that it mostly appears only after a couple of hours....?

The whole rig is in our rehearsal room, so that I can't immediately change things after getting ideas. The only thing I haven't done is to put the stompboxes through another patch device (got an RG16 spare).
Any good ideas?

[Marton]

Did you changed the battery in your bass ?

Maybe one of the tube is starting to go bad and have some problems when getting too hot ?

[KimGT99]

No, I didn't change batteries. Haven't thought about that one though
No, even when the amps' turned down, the buzz signal remains.

[KimGT99]

It seems that my T-rex fueltank is getting too hot after a couple of hours and then it can't deliver full power to the pedals what causes the buzz...