Sglaw461
Member
Hi all,
Am servicing a 9050 and have an interesting question. According to the service manual and schematic the emitter resistors are all 0.47ohm but on the amp boards in this unit 2 are 0.47ohm and the other 2 are 0.22ohm. Picture below. This looks like it came from the factory like this, and is surely not correct, would be very difficult if not impossible to bias and balance the outputs. Output transistors are all tested and working and are original Sanken 2SA1116 and 2SC2607. Drivers also tested. The only other anomaly is R25 and corresponding R26 have been changed from 680ohm to 470ohm. I cannot find any service bulletins that mention a build change so am hoping someone who has rebuilt one can enlighten me.
Many thanks.
Am servicing a 9050 and have an interesting question. According to the service manual and schematic the emitter resistors are all 0.47ohm but on the amp boards in this unit 2 are 0.47ohm and the other 2 are 0.22ohm. Picture below. This looks like it came from the factory like this, and is surely not correct, would be very difficult if not impossible to bias and balance the outputs. Output transistors are all tested and working and are original Sanken 2SA1116 and 2SC2607. Drivers also tested. The only other anomaly is R25 and corresponding R26 have been changed from 680ohm to 470ohm. I cannot find any service bulletins that mention a build change so am hoping someone who has rebuilt one can enlighten me.
Many thanks.
