The friend of mine has ASUS p4s533 motheboard with integrated C-Media CM18738 codec. Could somebody tell something about quality of this codec? And what's better -to buy Audigy1, or just use it?

Uhm.. Why isn't this in the audio hardware forum?

Anyway, I have a very similar board (p4b533, C-media 8738-mx). The noise level was to high for my taste (higher than my previous SB-live) and the card had some compatibility issues with games, so I haven't used it much.

The C-Media card that originally came in the computer I'm posting from right now (I'll be damned if I can ever remember the model no.), was downright horrible for MIDI, but was satisfactory for MP3 playback on our crappy egg-speakers. We replaced it after a few weeks with a SB 128 PCI.

Well, it has some potential (not sure if the P4S533 comes with digital i/o connectors though): http://www.nomad.ee/micros/digitalaudio.html

Gaming issues, strange... I have a 8738 6chan w/ Spidf&Optical and I havnt had any issues with any games yet. Ive had it up to EAX2 in hardware, A3D & OpenAL also no issues... Im now using directx9.

I just downloaded a new driver from windows update site too, so u might want to check that first too. As for noise, I wouldnt know, Ive been using the optical outputs since I had it... and my inputs are a delta1010 external. id use the delta for gaming too, but its just not a gamin card at all....

It was a crackling in the sound. I think it happened when the game was dynamically changing the volume of the sound effect; maybe this scaling was not continuous.

My version had coaxial digital in/out.