Audiophile USB to PCM


I have an excellent upsampler and dac (dCS Purcell/Delius) and am looking for the very best USB to PCM conversion. So far, I've tried SlimDevices Squeezebox, and Xitel Pro Hi-Fi link.

Both are very good, but I was wondering if there are any other options I should be considering. Both the Sutherland USB Preamp and the Wavelength USB Dac convert to analog. I'd like something of similar quality that stops short of the digital to analog conversion so that I can let the dCS gear do that.

Any suggestions would be appreciated.

harry
hbrandt
my path is about to be: RME PCI card output to DCS elgar+ for conversion with the card's WC slaved to the elgar in mastermode. the RME card claims to output 24/192 but isn't my signal from the PC stuck at 16/44? is it even possible to output 24/192 through AES/EBU or digital outs from a PC? if so, is this a function of the source files i'm using? i'm using masterclock mode to reduce jitter, but is this worth it if the signal is stuck at 16/44 and i'm not upsampling at all?
Rk_t, I think you hit the nail on the head. I'm sure someone could write software (or maybe it exists) to use the PC processor to upsample, but... seems to me that would be pretty processor intensive and subject to the vagaries of whatever other daemons or processes demand CPU time. I'm guessing you are better off matching your Elgar with a dCS Purcell if the upsampling really matters to you...
Rk_t, Empirical Audio's web site (Audioengr in this thread) suggests that one should use Foobar software to upconvert to 24/96, because it allegedly is better than hardware upsampling. There may be other software that upconverts to 24/192?

At the moment, what you suggest seems like the way to go: PC card outputting upsampled digital via AES/EBU, with card driven by DAC wordclock. As long as the card is not processing the signal, only outputting an upconverted but otherwise untainted PCM signal from disk. Seems like a better solution than a USB-to-digital converter that is not driven by a wordclock. I'm new at this, so if anyone disagrees or has the best way to go from PC to DAC, I'd also appreciate the suggestions.
I'd be interested in hearing from Audioengr, I'm curious how anyone can make the blanket statement that foobar's upsampling is better than hardware upsampling... Don't get me wrong, I love foobar. But, foobar is a piece of software written for consumer processors. High end companies like dCS and Theta have access to the same body of knowledge used to create the algorithms for foobar, plus the ability to use custom, specific purpose ASICs in hardware decoding that I have to believe can contribute to better upsampling...

That said, I've never run my foobar at 24/96. FBOW, I don't think my Waveterminal will pass 24/96. But, I've been quite happy with audio quality of my Waveterminal into a dCS Purcell/Delius combo...
Edsilva - I mod a LOT of different DAC's, and upsampling engines, including the P-1A, Benchmark DAC-1 and the DIP, so I get to hear the output quality of these hardware and firmware upsamplers.

The Secret Rabbit Code (SRC) upsampler with Foobar2000 is simply the best that I have heard, when played through my Off-Ramp converters. Software upsampling will always be more flexible for generating upsampling algorithms. Hardware and firmware implementations have limitations that software does not have. These algorithms are not trivial to implement in hardware, even using DSP engines.

Steve N.
Empirical Audio
Manufacturer/modder