2. amps-preamps
  3. 166449-96791

Preamp/interconnects cause amp problems?

My power amp, which sat, untouched for 3 years, always on and sounding great had a short in the power supply (cap gone bad?).

I sent it back to be fixed and and hours after getting back had the same issue. Manufacturer replaced boards and related pieces and is sending back but said they found nothing that they think would cause the issue.

so my concern is it’s something here causing it. Even though the manufacturer put the amp on the burn in rack for a week I’m worried it will have this issue again.

is it possible my preamp or interconnects could cause this? I have a loaner amp in place now for a few months and have had zero issues with it (same everything and save outlet)
but it’s a different (lesser) brand.
gochurchgo
gochurchgo OP
920 posts
 
Preamp was off. 100% off. DAC and phonostage are always on 24/7.

when I turned it off preamp
Is always connected. Tried with nothing connected and also with a passive connected and same thing .
fiesta75
1,378 posts
 
Sounds like for sure the power amp. The best way to troubleshoot problems like this is with freeze spray. Your tech should be aware of this technique. I have found failing pre-driver or driver transistors were the cause in some amps.
rh67
307 posts
 
A bad resistor in the power supply can cause the popping sound you mentioned hearing at night some amps will do this when there are issues in the power supply. If the manufacture would of had speakers hooked up to the amp they would have heard this the first time it was on their burn-in rack, they also should listen and not just take measurements. 

This time around i'm sure they took their time and fingers crossed all should be good.
gochurchgo OP
920 posts
 
He did mention something about transistor(s). I’m afraid my ignorance on electronics means I didn’t fully
process what he said.

my hope is he fixed the damamge last time but not the cause; and that cause has now been eliminated. My temporary amp has been hiked up 24/7 with no issue.
gs5556
1,234 posts
 
Popping sound in the speakers is dc. The amp either has a transistor problem, which is easy to find, or a short at the output caused by a wire or component fault, which is difficult to find. Could be carelessness in manufacturing in which case it’s a lemon and I would go for a replacement unit.
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