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Pacific's Restorations You can see all of Pacific's vintage gear restorations here.

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Old 02-10-2013, 11:33 AM
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Pacific Stereo Pacific Stereo is offline
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SX-1280 restore... time for another one!

Lots of photos in this one.

Time for another SX-1280. This one came in working, and this customer wanted a no-holds barred rebuild, and that's what he got! I'll start with some eye-candy...



OK, now that your "beauty shot" appetite is whetted, let's take a look at this one. I mostly remembered to take "before" shots.

UPDATE: I now replace almost all small-signal transistors on all boards with the exception of the tuner board.

This unit was in pretty good shape, and happily, it was working, so I could just dive right in and get to work. The first thing we do on these is the power supply. The supply runs really hot, and is the cause of many-a-problem when they get on in years. Here's the crispy critter:



and



Ugh, that bad boy is baked, baked, baked. We replace all of the pass transistors, the zener and regular diodes and of course, all of the capacitors. Note that the axial parts have been replaced by radials. I do this for two reasons. One is that I don't stock axial parts. The second is that the radial capacitors are generally better. Of course, we double-check all the resistors under the heat-tubing to make sure they are still good.

One thing that's nice about modern parts is that they are smaller. This is good because it gets them a little farther away from heat sources and also allows for better airflow. Oh- the surge relay gets a contact refurbishment, too.



All right, the power supply is happy again, so let's take a look at one of the power stages.



Nothing too remarkable here, just a rebuild with new caps and bias and offset pots. Film caps replace tantalum and the low-leakage input cap. Happily, none of the rare dual-transistor parts need to be changed out.



The next step is the protection board. We want to renew it and we want to change the relay transistor, because it runs in saturation all the time and can get tired. I change it for a more robust part. The other transistor gets changed, too.



This is where one either refurbishes the speaker relay contacts or replaces it. In this case, all this one needed was a little TLC. Here's the board after.



After the protection board, we start on the flat amp and tone boards. Here's the tone board before (I forgot to take a photo of the flat amp before):



And after. Because the tone amp is full of tantalum and low-leakage electrolytics, we can't use audio-grade capacitors in this circuit, as they are too leaky. I also don't particularly like the sound of tantalums, so I use all new low-leakage parts in this circuit. Look at those gorgeous precision attenuators!



And the flat amp. Here, we can use audio-grade electrolytics in some spots, and we do. I so wish all amplifiers had attenuators like these...



I forgot to take a before of the tuner board (duh), but here's what it looks like when it's done. These have great FM sections in them. This one also had some trouble in the AM section, which turned out to be some bad solder.



The phono board gets a little TLC, too.



Mmmm, like those film caps!



After all of the boards are rebuilt (switches and controls are cleaned and treated while we do that), of course she gets a full AM, FM and MPX alignment. Also, the power switch is torn down and serviced. And here's a look at the bottom:



Heh. You can also see my goofy collection of Sony badges, the Kikusui scope, the Leader millivolt meter and the Tektronix power supply in there too. And here's the back:



After a 12-hour burn in, power and distortion are measured, and she gets an audition. Perfect! And here's the Pile O'Parts:



All that's left is to put up more beauty shots (and send her back)!







What a lovely receiver. Her owner is just ecstatic, he loves how she turned out. I do, too.

All photos copyright 2013 Pacific Stereo. All rights reserved. No unauthorized use, and specifically, NO EBAY USE.
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I RESTORE VINTAGE AUDIO AND VIDEO GEAR. Master technician for Concept, Quadraflex, Calibre, Pioneer and Sony. Endorsed by Richard Schram for Concept product restoration. Factory technician for both Yamaha and JVC. Sonics consultant for Denon. Pacific Stereo store manager, service manager, Central Service lead tech, liquidator at our demise. Pacific Stereo curator. Infinity IRS dealer. Music buyer for one of the first CD retailers in the USA. Authorized servicer for virtually every brand on the planet at one time or another. Music addict. Mastering & recording engineer, weaned on a Neve (no other console sounds like a Neve!). Industry-respected ears. Head Tapehead.

Need vintage audio & video repair and restoration, or unobtanium semiconductors and parts? Ask me! And do visit the website: pacificstereo.net

Last edited by Pacific Stereo; 07-13-2016 at 08:30 AM. Reason: Updated
  #2  
Old 02-14-2013, 08:25 AM
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Socal Sam Socal Sam is offline
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Another Showboat! Good to go for another 30 years.

I see you did not replace the main filters.
  #3  
Old 09-09-2013, 08:10 AM
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Pacific Stereo Pacific Stereo is offline
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Yes, depending upon their particular condition, they may stay or they might go. In this case, they stayed.
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pacificstereo.net "Make your own kind of music!"



I RESTORE VINTAGE AUDIO AND VIDEO GEAR. Master technician for Concept, Quadraflex, Calibre, Pioneer and Sony. Endorsed by Richard Schram for Concept product restoration. Factory technician for both Yamaha and JVC. Sonics consultant for Denon. Pacific Stereo store manager, service manager, Central Service lead tech, liquidator at our demise. Pacific Stereo curator. Infinity IRS dealer. Music buyer for one of the first CD retailers in the USA. Authorized servicer for virtually every brand on the planet at one time or another. Music addict. Mastering & recording engineer, weaned on a Neve (no other console sounds like a Neve!). Industry-respected ears. Head Tapehead.

Need vintage audio & video repair and restoration, or unobtanium semiconductors and parts? Ask me! And do visit the website: pacificstereo.net
  #4  
Old 04-07-2016, 08:27 PM
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Pacific Stereo Pacific Stereo is offline
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Join Date: Feb 2010
Location: Somewhere in paradise!
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This must be 1280 month. Got one in the lab that just went through the Pacific cosmetic treatment after a rebuild (similar to this thread, though we now do a few more things to them than you see here) and I've had 2 inquiries about 1280s this week. The last "run" was 16.5s.

These sure do sound good.
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pacificstereo.net "Make your own kind of music!"



I RESTORE VINTAGE AUDIO AND VIDEO GEAR. Master technician for Concept, Quadraflex, Calibre, Pioneer and Sony. Endorsed by Richard Schram for Concept product restoration. Factory technician for both Yamaha and JVC. Sonics consultant for Denon. Pacific Stereo store manager, service manager, Central Service lead tech, liquidator at our demise. Pacific Stereo curator. Infinity IRS dealer. Music buyer for one of the first CD retailers in the USA. Authorized servicer for virtually every brand on the planet at one time or another. Music addict. Mastering & recording engineer, weaned on a Neve (no other console sounds like a Neve!). Industry-respected ears. Head Tapehead.

Need vintage audio & video repair and restoration, or unobtanium semiconductors and parts? Ask me! And do visit the website: pacificstereo.net
  #5  
Old 04-23-2016, 08:37 PM
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Pacific Stereo Pacific Stereo is offline
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Join Date: Feb 2010
Location: Somewhere in paradise!
Posts: 11,586
Apparently the owner agrees. Just got an E from him, happy as could be and now wants a second 1280 done. I just love that.
__________________
pacificstereo.net "Make your own kind of music!"



I RESTORE VINTAGE AUDIO AND VIDEO GEAR. Master technician for Concept, Quadraflex, Calibre, Pioneer and Sony. Endorsed by Richard Schram for Concept product restoration. Factory technician for both Yamaha and JVC. Sonics consultant for Denon. Pacific Stereo store manager, service manager, Central Service lead tech, liquidator at our demise. Pacific Stereo curator. Infinity IRS dealer. Music buyer for one of the first CD retailers in the USA. Authorized servicer for virtually every brand on the planet at one time or another. Music addict. Mastering & recording engineer, weaned on a Neve (no other console sounds like a Neve!). Industry-respected ears. Head Tapehead.

Need vintage audio & video repair and restoration, or unobtanium semiconductors and parts? Ask me! And do visit the website: pacificstereo.net
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