gonzothegreat
Super Member
I ordered a SANKEN substitute 2SA909 and 2SC1586 for the blown outputs (2sa679/2sc1079) in my Au-9500 and installed them Monday night. I wasn't sure if I could get away with just replacing the two outputs that were shorted or if I had to replace all four devices. The idea of dropping another $25 on outputs was not a pleasant one. I'm just glad they weren't SX-1980 outputs - I'm fresh out of Unobtainium (atomic number 666 - look it up for yourself)
Anyways...
I threw in a pair of 7A fuses and fired it up. The left channel was OK but the right (with the new outputs) had 1.5 volts DC on the speaker terminals. Thank goodness I had the sense to use a DMM before toasting some speakers.
I thought about it for a moment and 1.5vdc seems too high to be something I could null out with a DC offset pot. Not even sure if the amp has one. My gut tells me this is due to the different transistors but I don't know for sure. The next time I look at it, I'm going to swap the outputs between channels and see if the problem moves.
Before you ask, no I don't have the schems. As for the other obvious question, the serial number sticker reads 215050. Not sure if that's the complete number as my cleaning job soaked the sticker and might have erased a trailing digit or two
Anyways...
I threw in a pair of 7A fuses and fired it up. The left channel was OK but the right (with the new outputs) had 1.5 volts DC on the speaker terminals. Thank goodness I had the sense to use a DMM before toasting some speakers.
I thought about it for a moment and 1.5vdc seems too high to be something I could null out with a DC offset pot. Not even sure if the amp has one. My gut tells me this is due to the different transistors but I don't know for sure. The next time I look at it, I'm going to swap the outputs between channels and see if the problem moves.
Before you ask, no I don't have the schems. As for the other obvious question, the serial number sticker reads 215050. Not sure if that's the complete number as my cleaning job soaked the sticker and might have erased a trailing digit or two
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