trashcanman
Well-known member
- Joined
- Jan 26, 2016
- Messages
- 104
I have a Sansui AU-101 amp that I bought cheap as one channel was dead. Opening it up showed that one of the fuses was blown and it blew immediately again on replacement. I managed to trace down a few dead/shorted transistors and got it going again but the output transistors on one channel were still getting hot so I thought it would be just a matter of time before they died again and went further solving the issue.
The voltage from the power supply was quite a bit off and pretty basic so I replaced it with a diy version, basically that same but with a voltage regulator after the rectifier diodes and a few more smoothing caps. Where I'm at now is one channel works fine and is nice and quiet thanks to the new psu I assume, the other channel however causes the psu to crap out when I have the fuse in and my measurements indicate differences in resistance to ground when comparing channel to channel.
I'm pretty sure the problem is still somewhere into the output section but all transistors and caps test fine. My knowledge is pretty limited so if anyone has any advice about where to look I'd appreciate it. Below is the schematic.
The voltage from the power supply was quite a bit off and pretty basic so I replaced it with a diy version, basically that same but with a voltage regulator after the rectifier diodes and a few more smoothing caps. Where I'm at now is one channel works fine and is nice and quiet thanks to the new psu I assume, the other channel however causes the psu to crap out when I have the fuse in and my measurements indicate differences in resistance to ground when comparing channel to channel.
I'm pretty sure the problem is still somewhere into the output section but all transistors and caps test fine. My knowledge is pretty limited so if anyone has any advice about where to look I'd appreciate it. Below is the schematic.