SX-780 Volume Pot

rave0035

Disassemble first, ask questions later.
Hi - my SX-780's pots n' switches have given me a lot of trouble since it came off the bench. The volume pot needs cleaning every few months, and has now developed a 'dead spot' near the low end of the scale.

Anybody replace the volume pot in these? Are replacements available?

Mike
 
Bumping this... my research has still not found an available replacement that doesn't involve some mods. Anybody? I know this is a common failure in these otherwise awesome amps.

Mike
 
Thanks - plenty of salvaged units on fleabay, but was hoping to find a new unit given that these things crap out so often. Sounds like that might not be realistic.

Mike
 
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It's not Realistic, it's Pioneer. Realistic used the American Motors philosophy of using everyone else's surplus and rejects.

You can either retrofit in a "standard" unit without a loudness tap, or retrofit something like this into the chassis:

Hey, I have a soft spot in my audio heart for the Realistic brand. :) I really do.

Back to the thread

There are a few threads on replacing the volume pot with the loadness tap here on AK somewhere.
 
Watt; He might be too young for the AMC analogy.:rolleyes: How about DeLorean instead. The 1st batch used a Peugeot-Renault-Volvo "Douvrin" V6. Now THAT is a MUTT!
 
Chances are slim in finding a new part. basically have to take your chances with a used part or do the other mods as suggested.
 
One mention about the Realistic banter, that Realistic/Tandy contracted out the designs and manufacturing. The STA-2100 was made by Foster and used spec'ed out parts designated by Pioneer. In many cases the spec'ed parts were also Pioneer vendors. Remember the 2100's Toroidal transformer law suit?
There might be a cross to a higher end Realistic unit?
Worth a shot :dunno:
 
Another option would be to repair/restore the original pots. Unless the carbon traces are worn through, there isn't much else which cannot be repaired, even the bifurcated wipers and bushings.
 
MTF notes:
sx-780: acv-161 dual 100k, log (audio) taper, loudness tapped for pcb mount , NO detents

also used in:
sx-450, sx-550,
sx-580, sx-680, sx-780, sx-880
 
Thanks, all! I might get a replacement and give it a shot. Never tried my hand at restoring a pot... not even sure where to start there.

Mike
 
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