There's about 24 feet between my computer and my stereo in the next room. I just got an Edirol UA-3 external USB sound card to be the link between the two.

The guy at the stereo shop says the 8 meter shielded RCA cables will have a slight signal loss because of the length. Should I instead get a longer USB cable so I can use shorter RCAs? If so, at what length (if any) would USB cables be unreliable? Or do I not need to worry about any of this? Thx!

From this technical site:
http://www.qtec.info/service/ff/default.htm?fid=76



What means, you would need at least 4 USB amplifiers. I wonder if there are (simple, targeted at the home market) amplifiers for RCA cables.

Nevermind, I just found the answer. Here it is in case anyone's interested:

(from http://www.ebusinesscables.com/faqs.htm)
"The maximum length any standard USB cable is rated for, without amplification, is 15 feet. There are stories of people using several extenders to reach up to 40 feet but USB.org (site has all the White Papers, etc.) notes there could be significant data loss doing this. We strongly discourage using more than 15 feet for a passive extension cable. The best recommendation would be to use one of our Active Extension 16 foot USB Repeater Cables. These cables may be connected serially for lengths up to 80 feet. Data traffic is buffered to assure signal quality. Use the Active Extension cable coming from the PC or PC hub and use one of our $0.99 USB A/B cables to complete the connection to the peripheral device. The Active Extensions have A/A ends so they may be linked serially in a chain. Peripheral devices have a "B" receptacle (female port about 3/8" square) so you will need an A/B cable at the end of the chain to connect to the peripheral device."

woops, you beat me to it thx!

The loss in the analog cables will depend heavily on the characteristics of the cable, the output impedance of the sound card and the input impedance of the receiver. In my experience the cable capacitance is the most significant factor for the cable, so as long as you can find 100% shielded cable with very low capacitance you should have no perceptible/minimal loss in quality for a length of 24 feet or less. If you use the 15' maximum for USB that would leave your analog cable at 24'-15'=9' (plus slack on each end of maybe 3'+, so call it another 15'). Most reasonably low capacitance shielded coaxial cable should be able to handle this length assuming that you have relatively low output impedance on the sound card (<100 ohms) and relatively high impedance in the receiver (<=20kohms).

Note: low capacitance has very little correlation with typical expensive audiophile cable so don't assume that an expensive cable has low capacitance (often the opposite is true) or that a cable must be expensive to get low capacitance.

Adding a 5 meters cheap CINCH cable between the CD Player (470 Ohm) and the DAT Deck (47 kOhm) in addition to 1 meter of RG179 bu coax cable, SoundForge RMS level measured a difference of 0.00 db. The recordings made with and without the cable could not be ABXed.