Any insight with the Berkeley Alpha DAC ..??

Drubin - as for devices that use the audio stack in the computer, they are all the same in theory. However, the implementations and protocols used make some devices superior to others.

PCI cards are the worst because they rely on too much of the computer infrastructure, including the clocks and power system. Outboard converters, both USB and Firewire are generally better. However, there are good and poor chips available for both USB and Firewire, so it depends on the chip that was chosen for the converter, as well as the implementation.

By implementation I mean the Power System, PC board design, circuit design, cabling etc..

24/96 is supported on some USB converters/USB DAC's that use the TAS1020 chip from TI, as well as some Firewire converters. Only a couple of PCI cards support 24/192 at low quality, however they can be reclocked to provide high quality 24/192.

If you have to have 24/192, then a PCI card driving a reclocker is the best solution. If you are happy with 24/96, then USB is the best solution IMO.

Steve N.
Empirical Audio

Thanks Steve. There are an increasing number of USB-capable DACs out today, including the Benchmark, the Bel Canto, PS Audio, and several Wavelength models. At least for the first three, my impression is that their USB inputs are not exactly setting the world on fire. Why is that? Is there a trick to processing an audio signal via USB?

Back to the Berkeley Audio unit, I wonder how the new Bryston DAC stacks up against it. The Bryston, at 40% of the price of the Alpha DAC, seems fairly comparable features-wise, with the exception of no volume control and no HDCD. Just curious to hear peoples' impressions of both of these as they start to get out into the market. Given the price difference, you would think the Berkeley would be in another league -- and it may be -- but Bryston is, after all these years, probably quite efficient at design and manufacturing and they maybe can deliver more for less than a small company like BAD can. Maybe.

Drubin - I dont like to comment on the performance of other companies products on the forums, so I will send you an email.

The Bryston DAC unfortunately uses one of the lesser TI chips, not one of the good ones. However, I am actually in talks with Bryston about them designing my OEM USB module into their DAC, so this could improve significantly. There are several other manufacturers already designing the module into their products and you will see some of these debut at RMAF in October.

The Berkeley DAC is evidently designed by the Pacific Microsonics team that designed the excellent D/A modules in the past. I'm sure that the D/A module is a good one, however I believe this is their first "system" product. Have not heard one yet.

Steve N.

Thanks Steve. I look forward to seeing those products at RMAF. I assume you'll provide pointers to brands and room as the date approaches?

Steve,

Thanks for your response to my question. I haven't been back to this thread for a few days, but if your still around maybe you can clarify something for me.

You said:

There is no direct S/PDIF from a computer.

I take that to mean that you cannot extract digital information from a hard drive in S/PDIF format - it is first extracted in a different digital format and then converted to S/PDIF. My question is, where does that conversion take place and does it require a sound card? If you are saying that the conversion to S/PDIF must occur inside the computer, with the assistance of a sound card, then what does a USB DAC do that is different from a normal DAC? I was under the impression that a USB DAC converts the computer's digital format to S/PDIF as well as convert S/PDIF to analog, but I'm not really sure. Even if my impression is correct, maybe the sound card "sets up" the conversion to S/PDIF by performing some necessary preliminaries, like clocking.

I want to get the basic steps straight before tackling the details of implementation.