b&w as PC speakers

[dknightd]

Jim, I've never had great sound with buss powered usb dacs. Yes, most sound better than buit in sound cards, but I think using buss (i.e. computer power supply) holds them back (especially for hd650 headphones, which really need higher than a 5 volt power supply, which is all usb supplies - unless the device uses a DC-DC voltage converter).
Computer power supplies are usually pretty noisy.
From a jitter standpoint I'm not convinced that usb as usually implimented
has any advantage over firewire or spdif. It probably depends more on how
well things are implimented than the technology used.
I started with a buss powered usb soundcard (edirol). Then went to firewire (m-audio).
Then went to optical spdif. (the nice thing about optical is it completely isolates
the music electrics from the computer electrics)
The spdif sounds much better than either usb or firewire, but that could just
be because the DAC itself is better . . .
David

[jim777]

David, the device has DC-DC converters because it also has 48V phantom power available for condenser mics. This also means that any usb noise is filtered out. The noise floor for recording is a lot lower than the SNR in the specification so I beleive the specs when they say that the output (24-bit DACs) SNR is lower than 16-bit CD resolution (<100dB). I did test that verified that at least for audio only, the clock in the Tascam is controlling everthing and that it is Windows that is sending the audio at the rythm that the Tascam can play it and not the other way around. (I verified that it was in perfect sync for minutes with an other cheaper soundcard, sending the same buffers to both cards at the same time with special software, and it wasn't the case, so the clocks are independent).

All that being said, not sure a 200$ Tascam will beat a 975$ DAC1, but with a newer design and lack of jitter issues, it isn't impossible. Sorry I have no other DAC to compare with. One thing is for sure, it sounds 1000x times better than my internal Audigy2 at work (with a Rega EAR to be able to drive headphones all right)...

Thanks for your comments David. Your concerns were also mine when I got my card, and thats why I did the tests I mentioned up here

[dknightd]

I haven't heard Tascam. If it does Dc-Dc up voltage conversion to the headphone amp it can probably drive the hd60 just fine. It sounds like you are not using it for amplification any way, so that part becomes mute. Might be a great solution for a great price - DAC's improve faster than I can deal with.

I think we are on the same page here. If people judge computer sound by using
the built in sound card they are fooling themselves. A computer can actually make for a darn fine transport I use a cheap entech DAC at work, combined with decent speakers I think it it going to deliver decent sound at work.