oldtubes
Active Member
I have a Yamaha R-500 with a bad STK2040 module. The STK2040 is hard to find but I see the STK2240 is more common. Comparing the to chips on the internet the STK2240 looks like a STK2040 with internal emitter resistors. Has anyone tried to substitute the STK2240 for the STK2040 by removing the external emitter resistors?