advice for audio card OpAmps

[neong]

Hi all,

I want to better understand what is best to do for my audio:

Actually I got Audiotrak Prodigy HD2: http://www.audiotrak.net/products/prodigyhd2/

a nice audio card, with Rubycon caps, AKM AK4396 DACs and Fairchild NE5532 OpAmps. The OpAmps are swappable and I would like to change them with better ones. I read that almost everyone think the best OpAmps are the Analog Devices AD8620BR and the Texas Instruments THS4032 but...which one is better?

Plus:

the HD2 has three OpAmps, must I have to change all three or only one or two of them? I'm exclusively interested to improve sound quality for the stereo speakers analogically connected, don't care about headphones etc.

[Mooly]

Why don't you try the TL072. Don't discount it because of its age or it's price. Sonically it's much better than the NE5532, it's very stable ( something some others may not be particularly in sockets ). Consider also the OPA2604 -- I find this one of the best.
As for changing all of them, without a circuit it's impossible to say what they all do. It sounds like they are all in the audio path though. You can try different types in each location, no need to all be the same.

[sandyK]

The OPA2134 is normally an excellent choice replacement for the NE5532, and unlike the LM4562 series, it isn't as fussy about the quality of the supply rails. I am using a surface mount 2134 in the
L and R of my Creative X-FI card. The only other thing I did was to parallel a 100nF across the the main filter electrolytic.

SandyK