Pioneer SA6200 Rebuild Project Help

[colin.hepburn2]

Hi All
Well having a look around EBay I can across a pioneer SA 6200 which I snapped up for a mere £22.00 $34.00 I had one of these Amps years ago when I didn’t know too much a about Hi Fi sound then and gave it away. I seen to remember it sounding good at the time so thought I’d have another play with this one for a bit of fun. The seller did say it has a fault in one channel he described the sound as muffled and intermittent anyone have a idea of the cause or causes of this fault While I await delivery of the amp

Intended Work plan is to do a full recap using Elna Silmic RFS and Elna Cerafine Electrolytic and polypropylene Caps in the single path maybe Mundorf MLytic SI electrolytic for the Power supply Caps and a rewire And as I an still a beginner at this restoring game I would gratefully for a guiding hand though the process from the pioneer boffins I’m OK with a soldering iron and reading schematics
But I am inexperienced on the testing side of things like correct currents ext. But keen to learn from the members here and my biggest confusion is soring and selecting the best Transistors equivalents I just don’t know enough about this side of thing I look forward to reading everything you all can tell me about this Amp

OK I had a crack at sorting the transistors would someone pleas advice if I have this right if wrong would you mind posting the best one from this site if possible in stock
http://www2.cricklewoodelectronics.c...me.php?cat=176


SUBS 2N6126/2SA733/2SA1740
SA2600 POWER AMP
Q11/12/13/14.
2SA489/2N6126/PNP 8OV 4A 40W
Q9/10
2SA720/PNP 60V 500mA 200MHZ
Q5/6/7/8/15/16
2SC1318 NPN 50V 0AS 500mA
Q1/2/3/4
2SA726/2SA733 60V 100mA 200MHz
Control Board
Q1/2/3/4/5/6 2SA1740 50V 0A1 180MHZ
Phono Board
Q1/2/3/4 2SA1740 50V 0A1 180MHZ

[colin.hepburn2]

no replies
i really need the help on this one everyone pleas

[colin.hepburn2]

Hi All
Well it fun posting to one self i would be grateful for anyone help please

[sakis]

there is absolutelly no reason to replace a working transistor .... in many cases some transitors can be replaced for faster ones but this will not be a drop in replacement ..

faster transitors or more rugged ones if this is subject could be a choise but this will be a whichhunt for soemone with no expirience or methiods and instruments to verify the changes

so the idea will be to to bring the amplifier to original condition in the first place ... and then if this is not possible since some semis are not easy to find .... lets say as close is possible to the original condition and then should try changes very very carefully and always one step at the time ....

it is importand to know that many of the semis that you may think as replacements parts are actually not since are not original ....

here is also a can of information on restoring vintage amplifier repair/upgrade manual

[colin.hepburn2]

Hi Sackis
Thank you for posting I was beginning to think no one was going to post
My way of thinking was if one or two Transistors are blow and being aware the originals would be difficult to get.

it seems to make sense to replace with modern fast transistors but I would still need help with getting the right ones But I have so far just got round to testing it through pre amp only and that seems to be working fine I will let it play for a time and try the main amp I did note the left channel fuse was blown but could just be age

[colin.hepburn2]

Well that was short lived the pre amp has got a problem in right channel I also ran the power amp and that’s working fine but will be recap after I recap the PSU
I am running it from its pre amp out into the NAD power amp and I have just lost the right channel volume dropped by half its level as if I swung the balance over to the left
Next day
Well I have just switched it on in same configuration as last night and it working fine from Cold I will leave it running see how long it works for before trying its main amp odd well that lasted two and a half hours music drops down below the noise floor so the hiss is addible