I am repairing a Threshold 4000. The left channel had some blown transistors. I replaced all of them with MJ15024/MJ15025. Furthermore, I found 2x transistors (1x MPSA42 and 1x2N4250) and 2x resistors blown on the driver pcb (CFE 379).
Before powering up with variac I'd like your support on the bias setting. The emitter resistors are 1R. What voltage should I be measuring on them? I have found contradicting directions on the web from threshold owners/diyers and just wanted to know if there is any official bias procedure.
Any support will be really useful to finish this project and finally enjoy the amp. Regards!!
Before powering up with variac I'd like your support on the bias setting. The emitter resistors are 1R. What voltage should I be measuring on them? I have found contradicting directions on the web from threshold owners/diyers and just wanted to know if there is any official bias procedure.
Any support will be really useful to finish this project and finally enjoy the amp. Regards!!
