Asus ST PCI and upgrading op amps : the right choices

You're most probably not going to get audible improvements towards neutrality (if by that you mean higher fidelity and lower distortion and noise) by swapping the op amps from what it comes with.

You can see some measurements of the Audio-GD discrete op amps and many other op amps here:

http://www.sg-acoustics.ch/analogue_audio/ic_opamps/index.html

The Audio-GD ones are mostly worse if you want lower distortion, even with the higher supply rails.  I kind of wonder if replacing the computer mainboard or power supply with a different model might have larger benefits for getting lower distortion.  But maybe the PSRR of the chips is good enough.  Stereophile measurements of ST versus STX (in different computers; the cards themselves should be very similar) show different performance, for example:

http://www.stereophile.com/content/asus-xonar-essence-ststx-soundcards-measurements

though mostly I'm not sure if this experimentation will be fruitful if you're interested in results and not at all in the process.  That's just my opinion though.

Quote:

Originally Posted by bigski 
Hi everybody,

I am writing to you because I see that you are really well informed in the Head-fi forum.

I want to get better sound from my Asus ST. 

I like to have neutral sound, with more details,  and want to used up to 24/192 khz files .

I wanted to used 3 discretes op amps from Audio-GD for the buffer.  But the company tell me they are working with 18 volts, and my card are probably just 12 volts - /+.

Does somebody have tried that solution without issues ?

My budget is about 100 $.

And I can swap some capacitors, I have some Mundorf.   But wich one, on the card, will I need to change first ?

There is other things I can do to makes a good difference for the sound ?

I find the highs to hard, fatiguing, maybe to much of jitter. Non-engaging from the ASUS ST if I compare it to my Satch DAC.

Habitually I am using just the SP/DF out from the Asus to my modify SATCH DAC with valves, but I can just play 16/44.1 Khz files.  But the sound are smooth, musical and non-fatiguing.

Thank you all from Montreal,

Bigski

So you have an Asus Xonar Essence ST (PCI) and you want to replace their op-amps (operational amplifiers) with more neutral (with improved detail) op-amps.

(the Essence ST comes with one buffer op-amp and two I/V op-amps).

And you want to buy them from Audio-GD, but Audio-GD says they use 18 volt op-amps and they guess your Essence ST uses 12 volt op-amps.

you also want to replace the Essence ST capacitors with Mundorf capacitors.

Try posting this question in the "The Xonar Essence STX Q/A Tweaking Impressions Thread" and "The Op-amps" thread.