My beautiful SX-1980

Monday, January 30, 2012

Pioneer SX-1250 score!!!!!!

I just got a SX-1250, beautiful cosmetic condition and working, but only through the power amp. The preamp, or specifically the tone amp is shot, it has bad caps on it and when you flip the tone switch, it goes into protection. Also the indicator lamps are not working, that fault lies in the power supply, some transistors have gone belly up and are no longer supplying voltage to them.

The price? $75, and he was asking that even though he know that they were worth triple that, even with the bad preamp and transistors on the power supply. So if you read this Mark, thank you, thank you, thank you!

Here are some photos, I'm going to be giving this a drool worth restoration in the near future, so stay tuned!








Here are some before photos of the boards and other stuff, I'll keeping adding stuff as I get into it.

Equalizer amp


Flat amp


Control amp


Filter amp


 Left power amp board


Pins before



Right power amp board


Protection board


Stabilizer board


Power supply


Left channel filter caps


Right channel filter caps


A loose cap top


Right side of chassis before cleaning


Left heatsink before cleaning


Right heatsink before cleaning


I forgot to get a photo of the left side, but it looked like the right side above.

I just got my parts today (02/07)! The filter caps however won't be here for another couple of days.

Here are the parts:


And after recap and cleaning!

Equalizer amp board, 12 caps and 14 transistors on this board



Control amp board, 26 caps and 4 transistors were replaced on this board, also the controls were given a Faderlube treatment and the switch Deoxited.


Filter amp board, 4 caps and 2 transistors on this one, Deoxit was applied on all the switches as well.


Flat amp board, 12 caps and 6 transistors replaced, also Deoxited all the switches.


Left amp board, all the pins were cleaned and the board dusted and cleaned as well. 5 caps, 2 transistors (the input pair) and 2 variable resistors were replaced.




Right amp board, same thing done as above.


Protection board, new relay, replaced three transistors, upgraded two of them to bigger TO-126 case styles and replaced 6 caps. Also cleaned the board.


Stabilizer board, 16 caps, 13 transistors, 6 diodes and 2 variable resistors were replaced. Board was cleaned as well.


Power supply board, only 4 caps on this one, also checked the fuses for proper rating and any corrosion.


Left side of the chassis cleaned up


Left heatsink after cleaning


Left heatsink and boards put back in


Right side of the chassis cleaned up


Right heatsink cleaned up


Right heatsink and boards put back in


New filter caps in place!


Bottom view, left channel


Bottom view, right channel


Old versus new


And all back together!


It has been powered up and works great, tuner and indicator lamps are back on, I've now started the burn in process! Woohoo!

And here are the pics of it put back together! Warning, major drool alert, protect anything that maybe damaged by drool. You have been warned. :-D










This is hands down the best Pioneer receiver I have ever heard, the depth, clarity and power that the restoration has given it is something else, I can't describe it, it's something that must be heard to appreciate it. It will have a permanent place at the head of my rack, I don't think I will ever sell it.