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Pioneer SX-1250 Fixed by Tarior!!!

Brad Muller

Brad Muller

Super Member
I took the popping SX-1250 to Tarior along with my SA-9500ll. The 1250 is singing with no popping after 5 hours. I haven't auditioned the SA-9500 yet, but I'm sure it working as well. Arthur can fix this stuff! It's nice to find someone local who can do the job! Thanks again Tarior!!:yes: Brad
 
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Brad Muller said:
I took the popping SX-1250 to Tarior along with my SA-9500ll. The 1250 is singing with no popping after 5 hours. I haven't auditioned the SA-9500 yet, but I'm sure it working as well. Arthur can fix this stuff! It's nice to find someone local who can do the job! Thanks again Tarior!!:yes: Brad
Click to expand...

cam you say what the problem was?
 
What was the cause of the 1250's popping?

( I understand that Tarior may have to answer this..)

(edit: beaten again because of slow typing...)
 
I spoke too soon. One big loud pop and the sound went goodbye! It was working sweet until then. It has no sound now and just a loud pop at no volume level at all. It's headed back to Tarior. Hopefully, the problem can be easily traced now.:yes: Brad
 
It evidently had (has) more than one problem. The differential input pair on the left channel were noisy and popping. Also Q8 on the same channel was weak, and not allowing the left amp channel to bias properly. After fixing those problems, I ran it for three days straight, twelve hours a day and it seemed perfect.
Aaah well, I guess that's why we give a warranty on repairs.:grumpy:
 
Brad Muller said:
I took the popping SX-1250 to Tarior along with my SA-9500ll. The 1250 is singing with no popping after 5 hours. I haven't auditioned the SA-9500 yet, but I'm sure it working as well. Arthur can fix this stuff! It's nice to find someone local who can do the job! Thanks again Tarior!!:yes: Brad
Click to expand...


man Murphy heard that pronouncement loud and clear and evidently it was an otherwise slow day in MurphyLand and just couldn't let that one pass
 
I hear the Tarior warranty is pretty much second to none. That's because Tarior is what I call a pro's pro. He doesn't do it for the $$$, he does it because he loves it! He'd probably pay me just to let him work on all my broken gear.:yes: Brad
 
Yeah, actually it's great that we have so many entusiasths here. I found this forum when I had a problem, and got it solved with great support of Echowars.
Just keep it this way....
 
I sat down this afternoon and took another look at Brad's 1250. Turns out the (other) trouble was on the stabilizer board. Q4 (+25V regulator) was opening up and throwing the tone amp (and the flat amp, and the filter amp) into a tizzy whenever it would change states. Then things would settle down, it would come out of protect and play, sometimes for days. D2 was a questionable, and I replaced it, too. Furthermore, there were plenty of cracked solder joints, some (most) of which had to be cleaned off, the leads roughed up, and then fluxed and soldered, otherwise the oxidation on the leads wouldn't take any solder and would cause an open condition, which was giving me fits.
I went ahead and re-capped the board while I was at it, I wasn't about to have a cap go T/U and undo the whole damn thing.
 
tarior said:
I sat down this afternoon and took another look at Brad's 1250. Turns out the (other) trouble was on the stabilizer board. Q4 (+25V regulator) was opening up and throwing the tone amp (and the flat amp, and the filter amp) into a tizzy whenever it would change states. Then things would settle down, it would come out of protect and play, sometimes for days. D2 was a questionable, and I replaced it, too. Furthermore, there were plenty of cracked solder joints, some (most) of which had to be cleaned off, the leads roughed up, and then fluxed and soldered, otherwise the oxidation on the leads wouldn't take any solder and would cause an open condition, which was giving me fits.
I went ahead and re-capped the board while I was at it, I wasn't about to have a cap go T/U and undo the whole damn thing.
Click to expand...

That's what I did to my sx-3800 P.S. board (2 popped bipolars, 1 popped jfet and a shorted zener) that is on the bench now, plus I re-evaluated the voltage ratings on the caps being used, and looked to what they would be subjected to during fault conditions and upped the voltage accordingly, the cost increase was minimal (IF even noticable). Tektronix routinely rated their 4xx series scope's caps by double the expected voltage, and I have replaced VERY FEW over the years, so I feel that is a good example to follow.
 
I tried to up-spec the caps as best I could with what I had on hand, and I largely succeeded.
I don't know if you have a 1250 schematic handy, but Q4 runs hotter than I would like (runs at about 600mW), I think maybe R13 should be increased to about 1K ohm or even more. Comments?
 
Just use a better transistor. Step up from the wimpy TO-92L of the 2SC1384 to a TO-126 package, using something like the 2SC2497A (you can even add a heatsink to the TO-126).
 
EchoWars said:
Just use a better transistor. Step up from the wimpy TO-92L of the 2SC1384 to a TO-126 package, using something like the 2SC2497A (you can even add a heatsink to the TO-126).
Click to expand...

That is probably the best idea. I'm a little surprised that Pioneer used a somewhat marginal device there.
 
Tarior knows Yamaha's too :yes:
My CA 1000 is still singing like an angel, no warrentee work needed there.
He's the Man!
 
EchoWars said:
Just use a better transistor. Step up from the wimpy TO-92L of the 2SC1384 to a TO-126 package, using something like the 2SC2497A (you can even add a heatsink to the TO-126).
Click to expand...

I ended up using 2SC2344 (I have bunch of them), a little overkill, but it should hold up.:yes:
 
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