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In Reply to: RE: Ok, I'm going to ask this cap question here because I can't seem to get an answer posted by airtime on April 04, 2016 at 06:57:40
Charlie
If the cap is in the nested feedback loop,you can make the amp become unstable because the cap values were calculated into the equation for the operating parameters of a particular transistor and you can change the time constant throwing off that section of the amp.
If it's just coupling the input to the base of the first transistor,you probably won't notice it as you may have just lowered the corner frequency at the pole.Like Steve said, we really need a schematic and whether or not this is an integrated amp or just a power amp,basically I can tell you that if it's in the nested loop or global NFB loop,changing values will make the amp become unstable. SS amps typically are not as forgiving as tube amps when altering cap values in the signal path.
A friend you get for nothing,an enemy has to be bought
Edits: 04/04/16Follow Ups:
It's a Marantz PM8004. It was using a bunch of Elna caps in the signal path. I think they were all 33 or 22uf's???? and I replaced them with I think 47uf?
Getting rid of the Elna's REALLY and I mean REALLY cleaned up that muddy sound. Even with the wrong value.
If the OEM capacitors were ELNA Silmic II, I find it hard to believe they were responsible for the sonics you disliked. Those are among the one or two best for audio, IMO.Possibly one or more of the capacitors you replaced had gone bad, and by chance you got rid of it.
Edits: 04/08/16
You will be fine with those values you put in because that really isn't that big of an amount as going from 1uf to 25uf..How do you know those are in the signal path? They could in the regulator circuits as well.
A friend you get for nothing,an enemy has to be bought
I checked the schematic and many of them were coupling caps.
All were 22uf and replaced with 100uf
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