We have the Berkeley on display. I have spoken with Michael Ritter about the filter design. He won't disclose it other than if you play HDCD material, it has the proper inverse filter to handle that. I plan to co-write an article on the DAC and hope to get more detail then but I suspect it won't answer this question.
The front panel controls a set of filters but they recommend not using any other than the standard 1.16 and 1.24. The former is for playing CD and detects HDCD in that fromat. The latter is for 24-bit playback with 24-bit HDCD detection (which means it will NOT detect it in standard CD). Driven by a little async USB to S/PDIF converter, the sound to my ears is sublime.
I have chatted with dCS folks but I am not yet sure if we want to carry their product. Not because they are not good but because I just don't know if I can demonstrate additional quality. The Berkeley is less than half the price at $5K. The Debussy is $11K. My USB converter is only $500 (I do plan to test step up products from this one). So even if it is better, will there anyone pay for that difference?
I think it comes down to the custom DAC design that dCS has versus a week of burn in and hand tuning that Berkeley does on every box before it goes out. And the value of on-board HDCD detection.
Michael tells me that they have won shoot outs against dCS as long as the source is right which up to now has been the Lynx PCI audio card. He now believes (and I concur) that the best sound will come from async USB paired with it (with proper interconnect). Take the claim of winning over dCS as pretty biased though
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