Originally Posted by upstateguy
Here's what Marco Manunta just wrote to me regarding this issue:
"Our aim was to avoid using the USB cable which is generally the worst link of the chain."
That is what they aimed for. It doesn't mean they spent hours in critical listening in order to see which was the better. When I asked Marco if plugging the Hiface directly to the DAC, he didn't give a straight answer as I don't think he even tried it.
As you know, I like a lot the Hiface but this usb cable vs. digital cable is something they didn't think through enough and they didn't experiment with enough in my opinon.
Also, as regal pointed out, a company like m2tech is a small one and doesn't have the luxury to test every possibility. If they had spent months listening to different set-ups, choosing carefully every regulator, the clocks... we wouldn't be looking at a $150 but more something like $500+.
Originally Posted by ironmine
Aren't asynchronous USB-SPDIF converters supposed to be immune to the quality of USB cables? How can an USB cable be the "worst link of the chain" compared to a digital cable? My mind refuses to understand it. If what Marco says is true, then it contradicts to the design concept of Halide Design S/PDIF Bridge (www.halidedesign.com/bridge/).
Yes, ironically the usb cable affects most adaptive devices. The only effect the usb cable can have on a well designed async converter is on its power supply (EMI/RFI).
When I tried briefly the usb extender with the stock hiface, the change in sound was minimal in comparison with a change in digital cable. With jikeny's modified hiface, I find it very difficult to hear any difference between usb extenders.
My personal guess is that the guys at Halide Design are in the right track. The async operation makes the quality of the usb cable relatively irrelevant (except for carrying the power supply), so why not get rid of the digital cable that increases the jitter?
By the way, halide design are not only ones to follow that route: Audiophilleo is also suggesting to use a BNC to BNC adaptor to connect their converter to the DAC without using a digital filter.
Funny think, they included a feature called "virtualcable" to achieve a similar effect to changing the digital cable (by adding different level of jitter).
Personally, if I didn't have jkeny's modified hiface, I would have probably tried one of the two as they are clearly one step ahead of the stock hiface (albeit at a much higher price).