E-MU 0404 USB Modification?

[audiodesign]

yes, but I have excluded also the output stage

see
Hi-Resolution System 192KHz 24bit with EMU 0404 USB

[SoNic_real_one]

From the tests, I see that you constantly managed to worsen the output quality of the 0404.
Swapping the opamps with better ones would be a better aproach IMO.

[Pano]

For 1KHz he does show higher distortion. Tho it isn't awful and should not be audible.

But the real test is at >1KHz. That's often where opamp output circuits start to get nasty. Try 3KHz and its octaves. There may be some real differences. Ditto with multi-tone and IMD.

[SoNic_real_one]

Come on... I doubt there is any difference between 1kHz and 3kHz on any decent OpAmp. And past 10kHz... you don't hear the harmonics anymore.

[iko]

Did I mention that I replaced most of my opamps with top notch ones?

[SoNic_real_one]

I did play too replacing 5532 in different other equipments with NJM2068. Altough, not bad, the LM4562 is a way better choice.

[Pano]

Define "decent."

Measure and see. You might be surprised. I was.

[SoNic_real_one]

Well, for me LM4562 are decent. And all I need. Tube sounds worse to me - at least the ones that I heard.

[FOXYE]

Anyone tried LPF capacitor output stage?

[AndrewT]

Originally Posted by SoNic_real_one

And past 10kHz... you don't hear the harmonics anymore.

I can't tell I have heard the effect but the harmonics above audibility do create an audible effect.

Think about the 19kHz + 20kHz intermodulation test.
These two frequencies are sufficiently high enough that most listeners cannot hear the fundamentals. I'll bet most can hear the in band distortions readily.