Just purchased a Pioneer SA9800 amp for what I thought was a good price.Nice shape with no exterior scatches or dings.Hook up to my HPM100s and began to turn volume up,got half way and unit shut down.Turned volume back down and came back on.Did hear a click.Could this be a bad relay?I'm just an avid collector of Pioneer equipment.Any ideas. Thanks
Pioneer SA9800
- Thread starter murstang
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Masterdraco
Super Member
Amplifier went into protection check speaker connections, If you can measure the dc offset of the amp also have your hpm 100s been recapped.
petehall347
the brandy coffee man
try it without speakers connected see what happens .
You might want to consider contacting an administrator to get this thread moved over to the Pioneer forum, you might get more responses.
As for your problem, the relay is clicking off because of something going wrong. Sounds obvious right? If the unit works for long periods at low volume, maybe it has a high DC offset? I'm not sure how this would work, but if the offset is high, turning up the volume might amplify this until the protection circuit activates. The high DC offset doesn't always have to come from the power amp, there could be something going on in the pre-amp section as well. I had a Sansui AU-D11 mk2 that had a high DC offset (among other things), and that was coming from the pre-amp.
Another cause could be the amp is getting too hot when the volume is higher, and shutting off because of that.
Get this thread moved over to the Pioneer forum, and I'm sure you'll get more advice. Oh, and download a service manual.
Lee.
As for your problem, the relay is clicking off because of something going wrong. Sounds obvious right? If the unit works for long periods at low volume, maybe it has a high DC offset? I'm not sure how this would work, but if the offset is high, turning up the volume might amplify this until the protection circuit activates. The high DC offset doesn't always have to come from the power amp, there could be something going on in the pre-amp section as well. I had a Sansui AU-D11 mk2 that had a high DC offset (among other things), and that was coming from the pre-amp.
Another cause could be the amp is getting too hot when the volume is higher, and shutting off because of that.
Get this thread moved over to the Pioneer forum, and I'm sure you'll get more advice. Oh, and download a service manual.
Lee.
See if turning it up with NO sound going through it also causes it to click out.
also with no sound, after that when it is clicked back onto the speakers (ok a little sound for just a few seconds, then turn it back down) measure the DC voltage at the speaker terminals, get a DMM capable of reading millivolts and place the red meter lead on the plus or red speaker terminal, and the black meter lead on the black or minus speaker terminal, and read the voltage for that channel. then repeat on the other channel.
note to self: sa-9800 has output voltage limiters that do NOT trigger the protection circuit, thus no over-current (or speaker short) shutdown. protection shutdown is strictly DC triggered!!
also with no sound, after that when it is clicked back onto the speakers (ok a little sound for just a few seconds, then turn it back down) measure the DC voltage at the speaker terminals, get a DMM capable of reading millivolts and place the red meter lead on the plus or red speaker terminal, and the black meter lead on the black or minus speaker terminal, and read the voltage for that channel. then repeat on the other channel.
note to self: sa-9800 has output voltage limiters that do NOT trigger the protection circuit, thus no over-current (or speaker short) shutdown. protection shutdown is strictly DC triggered!!
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