When playing, it goes into std by when the volume turned more than 50%.
Speakers on /off doesn't matter.
Have narrowed it down to be R channel...
Not sure how to investigate further...
Speakers on /off doesn't matter.
Have narrowed it down to be R channel...
Not sure how to investigate further...
Check for DC voltages on the Pre/Power Amp jumpers with the BYPASS Switch OFF then ON (even though DC should be blocked by the coupling caps).
Post the results.
Good Luck!
Cheers.
Not sure what you mean by bypass switch.. Assuming it's the bridge /stereo switch?
No dc voltage with or without jumpers..
Didn't touch any switch though
Should be mentioned that i just recapped the whole amplifier.
Double checked for caps in wrong direction and so....
I suspect might IC 705 can be involved.
Since it's connected to r channel, and somehow low level function.
Since it's sometimes goes into low level, before std by....
Double checked for caps in wrong direction and so....
I suspect might IC 705 can be involved.
Since it's connected to r channel, and somehow low level function.
Since it's sometimes goes into low level, before std by....
No.
It was tested before.
Have double checked all caps are in right direction and place.
Compared with the channel working and against the schematics....
It was tested before.
Have double checked all caps are in right direction and place.
Compared with the channel working and against the schematics....
Was the amplifier functional before the re-cap?
Is this an induced failure?
IC705 is the useless MUTE/LOW LEVEL function, which is probably triggered when the processor detects the current/induced fault. It operates on both channels.
I'm guessing that when you stated the problem occurs when the VOLUME control is @ 50%, you were playing music. 50% of unknown is irrelevant!
Voltages and operating conditions are important!
You need to clarify what you were testing and under what conditions you were testing...
How did you determine that the right channel was causing the problem?
Good Luck!
I removed the pre out / main in link.
R pre out to left input plays well.
L pre to L main input same.
L pre to R main shuts down.
R pre to R main shuts down.
Also used another pre amplifier directly to main input, and it goes in std by
R pre out to left input plays well.
L pre to L main input same.
L pre to R main shuts down.
R pre to R main shuts down.
Also used another pre amplifier directly to main input, and it goes in std by
Nice diagnostic work! Now you need to find the problem.
Your "VOLUME 50%" statement suggests that the problem may be occuring when the high voltage rails are switched/utilised.
I don't have the circuit diagram available at this time, but check your previous work around the high voltage section of the power amp.
Good Luck!
EDIT: I've seen your post here. Apparently, the amp switches to Class A mode via IC705.
You need to inform NAD about this hidden feature (they may be surprised)!
Be careful when following information posted on The Internet (including this...).
It's ALL true (even if it's complete garbage)!
Are you testing the amp whilst connected to a 'lamp limiter'? If so, that may obscure the issue.
Last edited:
The pe stage / circuit are not the issue. It's been sorted out.
Have removed both 5 amp fuses for the HV rail.
And still the same.
It's not going into protection either.
So i just can't see, where it detects something wrong and goes into std by.
Have removed both 5 amp fuses for the HV rail.
And still the same.
It's not going into protection either.
So i just can't see, where it detects something wrong and goes into std by.
Have a thread at AK forum as well...
https://audiokarma.org/forums/index...yone-done-the-job.985422/page-3#post-15619286
https://audiokarma.org/forums/index...yone-done-the-job.985422/page-3#post-15619286