Pioneer SX-626 Rebuild

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
Hello all,
I stumbled onto this forum today, and let me tell you, you guys make me feel pretty stupid. I thought I knew something about audio :p

I picked up a Pioneer SX-626 reciever about 3 years ago. When it started to have some problems with noise etc, I started thinking about building something out of what DID work. I ended up removing the power supply board and the power amp board, and using them by themselves after I took them out of the original unit. After the amp stopped working, I looked at it and saw that one of the 2200uf caps on the board had literally exploded. The resistor that was next to it had burned up, but nothing else looked damaged. I replaced the cap and resistor, but instantly burned up the new resistor upon power-up.

Now, I don't know honestly much electronically about this amp design, but it has (4) 2SC793 transistors on it, and I would love to know if you guys think it would be possible to either troubleshoot this existing board, or build an amp from scratch using some of these parts. I also have the power transformer, but I have no idea what it's rated. It's super heavy though, and I've always told people that when it comes to amps, generally speaking the ones with the heavier power transformers are better-built. Am I off-base here??

If any of you think it's worth repairing the original board, I'd love some guidance as to troubleshooting this, as I don't really know where to start.
If not, I have some background in electronics, and my father is an EE, so I have access to test equipment and such. I'm not afraid of high voltage or a soldering iron, so I guess that's a decent start.

Jon
 
I like the old Pioneers (and have some in fact).

I would be tempted to stick a Class T amp in there however - or an el84 based tube amp if you were a bit more adventurous..

Well, see I don't have the original chassis, just the power amp board, power transformer, and the original 3300uF cap, which seems to just be a filter on the power leads.

That's why I was considering just building something different with these parts, assuming they are not totally fried.
 
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.