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SX-780 recap done

qprhooligan

qprhooligan

Well-Known Member
I just finished the recap on my sx-780. I used the cap list I found on the site here and I found some differences with my receiver from the list. Some of the caps in the manual call for low leakage caps and the list didn't have those specified as LL just normal caps. I went through the manual and changed some things on my order.

Also I had caps in my receiver that weren't even on the list. C207 and C208 for instance.

Replaced the big caps too, I used 10000uF 50v Nichicon, 647-uvy1h103mrd.

I also replaced the 8 diodes near the voltage regulators. I used 1n4004, and 1n5404 diodes.

Set DC offset.

I'm listening to it right now. It sounds wonderful.
 
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I also added a small heat sink to help with Q25 since it really gets hot. I also insulated it electrically.

You can see the new relay and some of the new caps, and diodes in this pic too.

sink-1.jpg
 
I have a heatsink installed just like you did and looks just like it but just a little bigger. It works well. It doesn't feel torching hot but hot anymore. Your black heatsink might be a little too small. How is the heat?
 
It is a small heat sink but I figured in addition to the original it would provide a bit more cooling. I didn't measure the temps before or after but it should work, and if not I'll improve the design if it fails for me.

I played the receiver for a few hours today and it didn't seem too hot. The receiver sounds great.

The only thing left to do is a bit of cleaning and I want to cover the case with real walnut veneer. I'm looking into how to go about that now.
 
I've got a Pioneer SX-780 and a Sansui 7070. The Sansui never gets played. The 780 is a GREAT sounding receiver. I havent recapped mine yet. Figured I'd do it when I need to. I had to replace the power supply in it when I bought it. I picked it up at a Flea Market for 25 bucks because it didnt play out of one channel. 60 bucks later, works great now.
 
Very nice! :music: I always like the SX-780 receiver. I should have kept one, but had too much gear. I think at one time I had six of 'em when you could get 'em for under $40 as repair units.


A bit off topic, but why don't we have a recap list forum? :scratch2: It would certainly help locating lists folks have put together on recapping projects. Hmmm....just thinking outloud. Sorry.
 
MAXZ28 said:
Very nice! :music: I always like the SX-780 receiver. I should have kept one, but had too much gear. I think at one time I had six of 'em when you could get 'em for under $40 as repair units.


A bit off topic, but why don't we have a recap list forum? :scratch2: It would certainly help locating lists folks have put together on recapping projects. Hmmm....just thinking outloud. Sorry.
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The sx-780 was my first good piece of gear, thats why I got this one. I have much better receivers but I still love the 780.

As for the recap list section, sounds like a great idea. Who do we talk to to get it done?
 
MAXZ28 said:
............ A bit off topic, but why don't we have a recap list forum? :scratch2: It would certainly help locating lists folks have put together on recapping projects. Hmmm....just thinking outloud. Sorry.
Click to expand...
There is in a sense; the AK database has lists people have put together for various makes and models. Just be aware that over the course of production there are often times service bulletins issued and circuit changes made for example.
 
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