Hello,
Thanks for scans!
Ahhh.... As originally built: The line out and the headphone amp utilize the same output IC so the headphone/line out amp cannot be ruled out (yet).
The headphone amp and the D/A converters utilize the same voltage line.
I need to read more on the mod to get a better idea of what the current state of the player is but some capacitors that have my attention are:
(The schematic is a bit hard to read (on my screen anyway) )
C304: 47uf @ 10v?
C307: 22uf @ 6.3v?
Both are attached to the IC's power supply line and might have something to do with distortion on both channels.
C102: 2.2uf @ 6.3v
Right channel coupling capacitor between the D/A converter and audio amp (it is probably tantalum).
Did this problem develop over time or did it suddenly happen?
Looking at the picture as to how the DAC's are stacked, it would appear that the signal from the original DAC is the signal having the problem. That is, both DAC's right output are being utilized. The original DAC is for the 'real' right channel while the new, stacked DAC's right channel is being utilized for the left.
Just to be sure, have the stacked DACs been revisted and the connections checked, perhaps reflowing the solder to a make sure there are no cold solder joints?
I know it would involve some surgery but I wonder if the DAC's outputs could be switched? (right DAC output now in the left channel audio output) If the sound is OK then the problem would most certainly be with the amp. In theory, the left audio (now in the right channel) would now sound bad. If the audio is bad in the left channel then the issue would be the DAC or further upstream.
Is that description confusing?
Kind regards,
Paul
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