Julien Pierre wrote: > However, besides the obvious portability advantage of USB devices, there > is one other interesting feature of USB audio, which is to isolate the > A/D and D/A converters outside the generally noisy computer case, and > this can provide higher audio quality than an internal PCI device. But > only the higher-end USB devices would really have that advantage. I have > used some low-end ones that were just as noisy as the first ISA > Soundblaster 1.0 (Edirol UA-1A if you must know). The UA-1A is bus-powered, and so picks up any noise on the +5V line. The noisiness of that depends partly on the mainboard, but mostly on the power supply unit. On my system with an Asus P4P800 MB and an Enermax PSU, I don't hear any noise, while on another system with an Intel TE430VX OEM board and a noname PSU, there is noise. In the latter case, the CPU is powered by the +5V line, too, and the noise can be reduced greatly by running distributed.net/SETI@Home/ whatever in the background to prevent the CPU from switching to idle mode. Regards, Clemens
