Official Blackstaramps Forum

Not turning the amp up cannot do that to an amp. You likely just have bad tubes that need replacing.

Replace the tubes.

You could just use a footswitch with a TRS type output, then split that output with a “TRS to 2 TR” adapter, one going to each amp.

Not dangerous.

Not many guitar amps use 15 inch speakers.

Static on amps is usually one of three things:
- bad tubes
- dirty tube sockets
- cold solder joints at the tube sockets

Given that your problem gets worse over time I’d think it’s the cold solder joints (as the amp warms up the solder joints change). I’d touch up all the joints.

Not really. If you go to a tube supplier you’ll find a version of 12AX7 with higher gain, but it has minimal impact. Biasing only relates to power tubes, which you don’t get most of your distortion from. Changing biasing will just impact whether the amp sound thin vs has a short tube life (it’s a ba...

If a tube amp uses 12AX7 preamp tubes then other tubes won’t really increase the gain. You can increase gain by using a Boost or Overdrive pedal in front of the amp.

What footswitch connectors/jacks are on the amp?

Preamp tube.