SX-780 question

jordanch68

New Member
Hello,

I bought three non-working stereos on ebay for $9.00 each two Pioneer's (450 and a 780) and a Sansui 5050. I've gotten the 450 and 780 working again and I had a question about the 780.

As part of getting it up and working I had to replace the 8000uf capacitor pair as they were dead. I used caps with a similar value (8000uf 50v). When playing the stereo the bass is good however the highs are a little flat. I was wondering if there are any suggestions on ways I can improve the range a bit.

Besides the two large capacitors I replaced 11 transistors. The three large transistors with heatsinks on the left, the six transistors in the protection circuit in the middle, and the two Darlingtons on the bottom. The Darlingtons were replaced with 80's instead of the stock 50's.

Any advice would be appreciated. Thanks!

CJ
 
You probably have some bad caps. When I got my SA-8800, I replaced about 15 cruddy looking capacitors before I plugged it in. Also clean the board. If any capacitors leaked on the board, they could be shorting out nearby components. I use high-temp Panasonic capacitors for replacements.
 
Thanks mosfet666, do you know of a source where I can get the type of caps you describe? I had a hard time finding the 8000uf 50v caps that I knew were bad.

Thanks!

CJ
 
www.digikey.com
You don't have to use high temp caps, any decent electrolytic will do. Digikey sells Panasonics, both 85 degree and 105 degree. The higher temp caps are mostly for that; applications in power supplies where the external temp is high or high ripple current causes the caps to heat internally. For audio coupling caps and most audio power supply caps it makes no audible difference.
 
Thanks dr*audio, that sounds good. I didn't go to digikey before because they didn't have the 8000uf 50v caps I was looking for at the time but they probalby have the other values.

CJ
 
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