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Luxman L-100 woes

SingleReel said:
You are correct, it does not have filter caps designated to right and left. If I'm not mistaken it has two hot wires coming off each filter cap to each power amp board. The swap was technically not isolating one or the other, just the wiring.
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Try some new ones maybe? Does it make any odd noises when you power it off?
 
SingleReel said:
You are correct, it does not have filter caps designated to right and left. If I'm not mistaken it has two hot wires coming off each filter cap to each power amp board. The swap was technically not isolating one or the other, just the wiring.
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Well, main filter capacitors are always connected like that. The output stage of the main amp gets +ve and -ve rails voltage from filter capacitors and the input stage of the amp gets the +ve and -ve rails voltage from the power supply board. Yes, there are both +ve and -ve rails.

I still suspect the filter capacitors are the probable source of the noise.
 
sanjib said:
Well, main filter capacitors are always connected like that. The output stage of the main amp gets +ve and -ve rails voltage from filter capacitors and the input stage of the amp gets the +ve and -ve rails voltage from the power supply board. Yes, there are both +ve and -ve rails.

I still suspect the filter capacitors are the probable source of the noise.
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That is where my mind went first, I just thought it was odd that one channel just gained significant noise over night, whereas the other didn't. One day I turned the amp on, and the extra noise came through the right channel and then moments later it disappeared. Listened for a few hours, fine. Next day the significant noise came back after start up and never stopped.
 
sanjib said:
Pin C09 is connected to the ground through the amp board. What I meant, take one port from your signal generator, and the ground component of the port will go to C09 and the signal carrying part of the port will go to C10. Another thing, when you disconnect the left input signal port from the amp board you still hear the noise?
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I have not put a traditional signal generator through it. When I remove the left input signal connector from the amp board the amp doesn't come out of protection. I jumped the ground C09 to chassis to get it out of protection to check, and the noise was still there.
 
SingleReel said:
I will try again and get back to you, but from what I remember it sounded like a standard power down, the live amp noise just quickly reduced to nothing with a moderate "pop" noise.
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I had bad caps in my Hafler dh-200 that made weird "8 bit video game" noises... Garbled sound on discharge .. new ones made that go away
 
sanjib said:
Your probable last bet I guess to put some new filter capacitors.
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I have been thinking of giving it a try. This model has some massive custom Nippon Chemi-con filter capacitors that there are no similar sized replacements for mounting. But, interestingly enough a few months back I sourced a pair of the exact same caps from an L-110. They were allegedly pulled working and fully tested within spec. Being from a later L-110 they would be marginally less old. Could be a lateral move, but I have them on hand and they may make a difference and reveal the old main filter caps as the culprit. Any opinions on this idea?
 

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Luxman filter capacitor replacement is a pain. I am still looking for the right size for my M-4000! What are the length and diameter and lead spacing on these?
 
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