Here you go cut and pasted from Emprical Audio Website:
Rip to WAV or AIFF files if possible
Try Upsampling 44.1 files to 24/96 using S/W programs: SRC, iTunes, R8Brain or Adobe Audition - Wave Editor on Mac (Instructions are on the Empirical Audio audiocircle.com forum)
Avoid ripping to ALAC or other compressed formats using iTunes
Avoid using iTunes on a PC for audio playback
Using iTunes by itself on Mac compromises sound quality and resamples files unless you specify sample-rate. Use Amarra, Pure Music or AyreWave on Mac. We find full Amarra version 1.2 to be the best sounding, although its not the most stable. We are optimistic about 2.1.1. The Equalizer function of Amarra is wonderful and essential for best system optimization.
Set 64-bit mode on PC or Mac for better sound quality.
Avoid Windows Media Player on PCs. Use instead Foobar, Jriver or Media Monkey. Better sound quality
If using a PC with XP, always bypass KMIXER using Kernal Streaming. If Vista or Win7, use WASAPI:
Mac Mini has the least problematic USB ports.
Recent PC Laptops are recommended, particularly those with ungrounded power cords. We have had good luck with Toshiba,HP, Macbook and Mac Mini. Not so good with Dell.
If you are using USB output to one of our products, we recommend that you try more than one USB port on the computer. They are often not equal. The latency or time it takes to service them varies even on the same computer. Some are even USB 1.1 and not USB 2.0 compliant.
Dedicate the Laptop to music playback if you are using USB. Using the computer for lots of other tasks can cause conflicts, increase latency and cause popping in the audio.
If you are using USB for audio streaming, do not attach ANY other USB devices to the computer, even a mouse and particularly not USB disks.
Remove or stop all unnecessary tasks, even screen-savers and virus scanners.
Set the player to have the highest priority.
PCs with faster processors work better, minimum 1.5GHz
Vista needs 4GB RAM and XP 2GB RAM
For Mac, 4GB is minimum RAM.
The best ripper we have found for PC (the best overall) is dbpoweramp professional with Accurate-Rip enabled:
For Mac, we recommend XLD for ripping (also enable Accurate-Rip):
Also worth trying is MAX:
For PC, try Foobar 0.8.3, Jriver, Media Monkey and XXhighend:
For PC, the best upsampler is Adobe Audition:
For Mac, the best upsampler is Wave Editor (uses Izotope code):