hi, i have an old pioneer sa-5300, which used to sound great until about 5 years ago when the left channel crackled, causing the channel to completely turn itself off, and then on again, it also doesn't have as much grunt as it did before, i was wondering if anyone has any ideas as to what parts to replace to bring this baby back to life, and if possible any modifications to make it better than it ever was!
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for me i replace caps. and recheck solder joints replace power resisters where needed. i would need it in front of me to find the problem
i get allote of old amps that work but dont have the power thay
had so replaceing old caps help thay dry out
for me i replace caps. and recheck solder joints replace power resisters where needed. i would need it in front of me to find the problem
i get allote of old amps that work but dont have the power thay
had so replaceing old caps help thay dry out
Those weren't half bad amps. I suspect you have a damaged input pair transistor, probably from being overdriven (I WANT IT LOUDER!!). Second guess is a weakened output transistor, or damaged Vbe multiplier transistor. Given that is still plays, that sort of points to the input pair, weak and giving extra offset so the relay is intermittent on closing.
It's nearly impossible to diagnose this with the little information you suggested, but I've repaired a few of these and that's my hunch. You really need a scope or at least a DVM to work on these. Maybe it's time to take it to a tech??
It's nearly impossible to diagnose this with the little information you suggested, but I've repaired a few of these and that's my hunch. You really need a scope or at least a DVM to work on these. Maybe it's time to take it to a tech??
yeah, it probably was from being overdriven, i however do not think that getting a tech onto it would be worthwhile, as that would probably cost more than the amp is worth itself. I tried the local electronic stores today for the caps and they only had a few of them, which seemed useless, anyone know a good place in sydney to get a wide range of caps? Is it possible to use bigger caps to give more headroom?
right, all the caps have been replaced and the sound is noticeably better, i'm thinking of replacing the transistors with more powerful one's, or do i have to match what i've already got. any help MUCH APPRECIATED
I don't recommend wholesale replacement of all transistors. You can do a lot of damage to the board when you desolder, and they don't wear out. Just the outputs and input pair seem to take a beating and fail, in my experience. Fix what's broken, leave the rest alone. Is your crackling sound gone? If so, let it be...
Some Japanese transistors have a different pinout than the common USA transistors, so you have to check the pinout of any device you remove and put the same type in. There are literally thousands of part types, so no universal crosses can be listed.
To do this right, you need to get the service manual if you are not able to wing it based on experience.
Some Japanese transistors have a different pinout than the common USA transistors, so you have to check the pinout of any device you remove and put the same type in. There are literally thousands of part types, so no universal crosses can be listed.
To do this right, you need to get the service manual if you are not able to wing it based on experience.
crackling sound is gone most of the time, however the right channel still turns itself completely off from time to time
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