Traynor YBA-1 oscillating!

[waspclothes]

Hey guys,
I have a Traynor YBA-1 head that just makes an audio frequency oscillation at the output. The frequency changes based on the settings of the volume knobs and tone knobs.

The first thing I did was pull tubes to figure out where the oscillation is. With V1 pulled, the oscillation still happens. If I pull V2 though, the oscillation stops. I also tried swapping out V2 just to make sure it's not the tube itself. I've also cleaned all the sockets and pots.

The schematic for the amp is here: http://www.lynx.bc.ca/~jc/YBA1Schems.pdf (specifically, page 6)

V2 A and B just seem to be straight-up amplification stages after the volume control, but before the tone control. I'm pretty new to this, but I don't see any big oscillation potential (no feedback loops). I did poke around the lead dress on V2, but nothing seemed to make the oscillation go away.

Is there anything else you guys suggest I should try to make this oscillation go away?

[Jazz P Bass]

My first thought would be to check the power supply capacitors for ripple.
Specifically C22 as it is being used to 'decouple' the signal from the supply.

You should also check for any coupling caps that may be leaking high voltage into the next grid.
A leaky C2 would put voltage on the volume pot and V2 grid pin 2 when the volume control is raised off of ground.