Mini 2018 > DAC with poor USB-input sound quality

netdog

macrumors 603
Original poster
Feb 6, 2006
5,762
36
London
Hi

A client has a Rotel which, by all accounts, has great sound EXCEPT when using the USB input.

He wants to be able to play stereo music up to 24/192 from a 2018 Mac mini > Rotel DAC > amplifier > speakers.

Normally, I'd probably have gone USB out to USB in, but let's forget that option.

It would seem that we've got to get the signal from the HDMI, USB-C (preferable in terms of future support), or USB-A (also on the mini) to a coaxial/optical input.

I know there are some devices for USB-A > Optical, but wondering what any audiophile digital audio fans here would suggest as the best solution short of replacing his DAC (matched to his pre-amp and amp so reluctant to do this). Also reluctant to by-pass his existing DAC.

Any and all help welcome.
 

netdog

macrumors 603
Original poster
Feb 6, 2006
5,762
36
London
Two reviews say that the optical input sounded considerably better than the USB. I don't know why and until I get a way to get Lee's Mini to speak well to the optical input, I won't be able to compare. That said, it's not a comment that I frequently read, and so when I saw it twice, I took notice. And no, the reviews were quite different, so I don't believe that one reviewer was just cribbing from the other.
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https://www.thomann.de/intl/si/rme_digiface_usb.htm

might be overkill, but RME has really solid drivers, build quality and long-lasting support.

This looks interesting. Do you have experience with one?
 

Ploki

macrumors 68040
Jan 21, 2008
3,991
1,274
I have experience with various RME devices, not that one in particular.

I'm going to buy one for the studio in the fall when all rooms will be wired via ADAT.

They have splendid driver support and even the old Fireface400 I'm using still works on Mojave. As far as audio devices go, I think these are the most solid build devices with hands down best drivers you can get.
 

VideoFreek

macrumors 6502
May 12, 2007
454
52
Philly
Late to the party, but more options here

http://www.thewelltemperedcomputer.com/HW/USB_SPDIF.htm

My question, though, is why does the Rotel DAC suck when using the USB input? Audiophiles will tell you that computer USB is noisy and therefore a no-go, but testing shows that competently-designed DACs handle computer USB with ease. That said, not all DACs, not even some darlings of the Audiophile community, are competently designed. See https://www.audiosciencereview.com/forum/index.php?forums/digital-audio-dacs-streamers-servers-players.8/ for details. Your best bet, rather than spending hundreds on a USB-SPDIF converter or any of a number of USB "decrapifiers", would be to invest in a better DAC. I don't buy that the current DAC is "matched" to his preamp; if a DAC does what it is supposed to do, no "matching" is required.
 
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