Hi, my advice is to leave the Denon amp as it is. The small Denon amps are usually fairly good, and relatively well designed. You can not easily improve it. Changing opamp will not help anything.
Better to spend your time building a nice simple amplifier kit, and learn something in the process
Better to spend your time building a nice simple amplifier kit, and learn something in the process
Hi, I would replace the NE5532 dual opamp (although it still is one of the best/better measuring opamps) for a JFET input type like OPA2132. Check the current supply voltages and make sure the new opamp has the same or better abilities. NE5532 can have +/- 22V max. which is rare among opamps but it may very well be that they are fed +/-15V in this amplifier.The circuit has an input filter and seems well decoupled so you likely won't encounter nasty side effects. Don't exxagerate by using extremely fast opamps.
C327 should be replaced for (preferably) a quality bipolar type like MUSE bipolar. You may up the voltage rating to 16V or 25V as long as they fit and have the same footprint. It is strange that polar caps are used but it is probably cost related. C323 can be replaced for one of the finest film caps as cost is low for such a value. I would change C325 and C395 for styroflex type film caps. Please make sure all the caps you will use fit physically so do not use "dangling caps" and melt glue contraptions. After the work please check idling current and adjust according the service manual.
In mainstream HiFi gear parts are chosen because of their low cost, not on their qualities.
C327 should be replaced for (preferably) a quality bipolar type like MUSE bipolar. You may up the voltage rating to 16V or 25V as long as they fit and have the same footprint. It is strange that polar caps are used but it is probably cost related. C323 can be replaced for one of the finest film caps as cost is low for such a value. I would change C325 and C395 for styroflex type film caps. Please make sure all the caps you will use fit physically so do not use "dangling caps" and melt glue contraptions. After the work please check idling current and adjust according the service manual.
In mainstream HiFi gear parts are chosen because of their low cost, not on their qualities.
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I have a Denon PMA-300V that I bought for $10 because it had broken speaker terminals.
The circuit is slightly different,but since I'm not an EE and since I don't know any better,I changed the M5218 opamp with a Signetics 5532. The sound opened up nicely. I'm actually listening to it now.
Cheers
The circuit is slightly different,but since I'm not an EE and since I don't know any better,I changed the M5218 opamp with a Signetics 5532. The sound opened up nicely. I'm actually listening to it now.
Cheers
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