I just bought an M-Audio Transit to replace my crappy Creative Extigy.
Feedback :

• There is a clear difference in the sound quality (resulting I guess from 16 bits --> 24 bits capability)
• The Transit works fine on my outadated Laptop (Celeron 333 Mhz Win98SE) through ASIO driver without much resource consumption if I choose the "High" or "Very High" latency option (which is not a problem as I use the card mainly for playback)

The only problem is that I hear an annoyong crackling sound a startup (or when plugging/unplugging the USB).


Any Idea to fix the problem ?

I don't think it resulted from 16-bit -> 24-bit, but rather the internal workings of the DAC. Unless you have any higher resolution souce such as DAD or SACD...

I made the same change and it was a huge difference. As Cyber-spanky said, it's not to do with going to 24 bit.
Does ASIO work perfectly for you? I sometimes get clicks even at high latency on the computer I'm using atm. Could be a problem with my usb bus. Don't think you can do anything about the crackling sound. I think it's to do with the sound card setting the sampling rate when it gets music to play.

I have one - i get that with using ASIO, particularly at startup.