Acoustic 370 - troubleshooting power amp

[Matt C]

I'm working on repairing an old Acoustic 370 bass amp. I am stumped and here to seek advice. The problem seems to be within the power amp section (I've attached a schematic.) When I turn it on, two resistors burn (they are highlighted in the schematic.) This has happened a few different times. At this point I've replaced almost every component in the power amp circuit, and still get the same results. The most recent time, the amp seemed to be stable for a few minutes and the power amp circuit seemed to be biased appropriately, but as soon as I applied signal, these same two resistors burned.

While there could be other issues hiding, I'm fairly sure the power supply and the preamp circuit are working fine.

My understanding of solid state circuits like this is pretty limited, so I'm a bit stumped here. Anyone have a clue for me?

 

[CJ]

Look for a possible solder bridge between traces, I see no logical reason why those two R's would have cooked due to shorted transistor or diode but you might have bridged something when replacing parts.