I am using my "old" NAD 705 Stereo Reciever mostly as Preamp and Tuner in conjunction with the PC and a "gainclone" as poweramp.
Some days ago, I changed two opamps (4558 and 2068) by OPA2134.
I wondered myself about not figuring out any bypass caps nearby these chips.
So I attached 470uF Panasonic direct at the voltage pins to ground.
Result: 100Hz buzz.
I tried different value of caps and tried to figure out another gnd plane.
But, still buzzing, with or without additional bypass caps. When I insert the original opamps:
Silence, as it has to be.
Now, I am looking for a service manual for this amp, but NAD manuals seems to be hard to find.
Any help?
Franz
Some days ago, I changed two opamps (4558 and 2068) by OPA2134.
I wondered myself about not figuring out any bypass caps nearby these chips.
So I attached 470uF Panasonic direct at the voltage pins to ground.
Result: 100Hz buzz.
I tried different value of caps and tried to figure out another gnd plane.
But, still buzzing, with or without additional bypass caps. When I insert the original opamps:
Silence, as it has to be.
Now, I am looking for a service manual for this amp, but NAD manuals seems to be hard to find.
Any help?
Franz
Hey Franz,
I got mine (manual) from ebay for around $13US shipped. I think there are always a couple listed. If you're still looking.
I got mine (manual) from ebay for around $13US shipped. I think there are always a couple listed. If you're still looking.
TRy www.servicemanuals.net. They specialize in service manuals for virtually all brands of consumer hi-fi products. They also carry most replacement remote controls.
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