[sdiy] audio op amp replacement

[Rob Keeble]

Hi
There are lots of different views on the sound of Op Amps....The NE5532
sounds pretty good to start with, so you'll need to explore more expensive
Op Amps to get improvements (5.00+ US dollars each), the OP275 is just one
option. It also worth noting that Op Amps are often used to "smooth
out/adjust" after a DAC in a CD player etc, and this is a different
application to a mixing desk. Check these links out:

http://tangentsoft.net/audio/opamps.html
http://www.diyaudio.com/forums/showthread/t-52793.html

I use OPA134's for the audio path of my modular synths, but beware upgrading
to any new FET Op Amps as they could well cause HF oscillation problems when
replacing NE5532's. The NE5532 may be "old" but they are cool (warm?).
Perhaps worth a trial on one channel strip, using sockets.

You might have more sonic impact looking at the capacitors used in the
filters and audio path. Along with stable power supplies and good strong
decoupling.

Regards
Rob

-----Original Message-----
From: owner-synth-diy at dropmix.xs4all.nl
[mailto:owner-synth-diy at dropmix.xs4all.nl]On Behalf Of Oakley Sound
Sent: 08 February 2006 15:11
To: Synth DIY
Subject: Re: [sdiy] audio op amp replacement


 > Adam caught wind that changing these out to OP275s would improve the
sound quality.

Tell Adam to keep the 5532. The OP275 may well have less current
consumption, higher input impedance and better DC specs. But for sound
quality the 5532 just sounds better. At least to my ears anyway...

This does assume that the manufacturers of the desk have kept the
resistance in the circuit surrounding the 5532 accordingly low. Anything
above 47K and you probably will be better off with the OP275.

Tony

www.oakleysound.com