Halide Design S/PDIF Bridge USB-S/PDIF converter Page 2

I changed to the Esoteric D-07 processor that I have in for review, now using the RCA version of the Halide Bridge. (The Esoteric has RCA S/PDIF inputs, whereas the Benchmark has a BNC.) I had previously auditioned the Esoteric feeding its AES/EBU input from the Ayre C-5xeMP's digital output, and if there was a difference to be heard when I switched to the Mac mini driving the Halide Bridge, I was hard-pressed to hear it.

I swapped the Esoteric for the Logitech Transporter DAC and again compared disc sources played on the Ayre and fed to the Transporter's AES/EBU input to the BNC Halide Bridge driving one of the Transporter's S/PDIF inputs. Again, the differences were small. Certainly, if I left the room, then reentered after someone had randomly switched between sources, I wouldn't be able to tell you which one was playing purely by listening. It was that close.

It was time for a more relevant comparison.

Enter the Stello U2
My review sample of the Bel Canto USB Link 24/96 has long since been returned to the manufacturer, but the Stello U2 ($349) has been my go-to device for using my Mac mini as a legitimate high-end audio source since I reviewed it. (If you attended any of the demonstrations I presented at Colorado dealer Listen-Up's three stores last May, the only source I used was my MacBook with the Stello.) The only problem I have had with the U2 is that it won't work transparently with audio files sampled at 88.2kHz. This is a shame, as almost all of my own recordings are made at that sample rate (footnote 2), as are many of those I have downloaded from Linn Records. The Halide Bridge solves that problem, but for CD-quality audio and 96kHz-sampled files, the acid test of the $100-more-expensive Halide is how it rates against the Stello.

For the comparisons, I used the NAD M2 integrated amplifier that I reviewed last March. The M2, basically a DAC that can power loudspeakers directly, worked well with the Stello, providing a superbly transparent, grain-free presentation. (I used the pairing at the third of my Colorado demos.) I had both converters plugged into the Mac mini's USB ports, and they fed the NAD's two coaxial inputs. Switching between them involved resetting the Mac's default audio output to one or the other device and changing the input on the NAD. This didn't make possible an instantaneous switchover, so I tended to listen to long passages at a time on one converter, then on the other, then back to the first.

Admittedly, the difference between the Stello and Halide was small in absolute terms. However, over time I did tend to prefer the Halide Bridge's sound. For example, with pianist Robert Silverman's performance of Robert Schumann's Symphonic Etudes (which I recorded in Goshen, Indiana, in 2008, for CD release next spring), while the amount of Sauder Hall's delicious acoustic that could be heard to be excited by the piano was the same with each converter, that acoustic seemed a bit more of a piece with the direct sound of the Steinway when the Halide was handling the data. The instrument's upper register seemed a touch more prominent with the Stello, which emphasized the effect of the sustain pedal a little—something you don't want with Schumann—while the piano's left-hand register seemed fuller through the Halide. On "Somewhere in Hollywood," 10cc's pastiche of "A Star Is Born" from Sheet Music, every small detail of this intricate arrangement was laid bare without anything sounding spotlit or exaggerated. (In this new century of formulaic pop pap, I marvel that, in 1974, a pop band like 10cc could put out an album like this, with every song different from every other in every way, and have it make the charts.)

I finished my comparison with Peter Gabriel's Scratch My Back (ALAC files, from CD, EMI), which has been in heavy rotation since I heard Dynaudio's Mike Manousselis play it at the 2010 Salon Son et Image in Montreal. I could still live with the Stello U2, but the Halide S/PDIF Bridge let Gabriel's idiosyncratic readings of others' music through that little bit more readily.

Summing Up
When USB–S/PDIF converters can be had for not much more than $150, a product providing the same functionality but costing three times as much needs to offer sound quality that is beyond criticism. Fortunately, that was the case with the Halide S/PDIF Bridge. With all the D/A processors I used it with it, even the jitter-prone Assemblage DAC-1, its grain-free presentation stepped out of the music's way in a very welcome manner.

The Halide Bridge is limited to sample rates of 96kHz and below, which may be a problem for some users. For me, however, that was more than outweighed by the fact that it will function correctly with 88.2kHz data. And, of course, its owner doesn't have to buy a separate S/PDIF cable to use with it. It is also truly plug'n'play.


Footnote 2: This is because I make recordings for eventual release on CD, and the conversion from 88.2kHz to the CD's sample rate of 44.1kHz preserves as much as possible of the original's quality. By contrast, the 96-to-44.1kHz operation is computationally complex and easily compromised. And if shortcuts are taken to allow the change to be performed in real time, such as when you play a 96kHz file in iTunes when the latter is set to operate at 44.1kHz, the sound is made significantly worse. That's the beauty of front-end programs like Amarra and Pure Music: they eliminate the possibility of iTunes invoking its poor real-time sample-rate converter.
Halide Design/Devilsound Labs
(858) 224-3551

rashumon's picture

Hi There,
You mentioned in your review that only a few DACs use USB asynchronous mode and mentioned those that you thought did. but you forgot to mention the HRT MS product which also works in asynch USB mode and at a price very similar to the Halide design reviewed here.

It was reviewed by Stereophile in Nov 2009 with positive results...

Would be good to see your opinion of how these compare to each other...

stereodudeiii's picture

Suppose your USB port is 2.0 instead of the older 1.1 - makes any difference (I understand that from a purely computer perspective, USB 2.0 is [supposedly] backwards-compatible with 1.1 - the question is from an audiophile perspective)?

John Atkinson's picture
"the HRT MS product which also works in asynch USB mode and at a price very similar to the Halide design reviewed here. It was reviewed by Stereophile in Nov 2009 with positive results..."

The first-generation HRT Music Streamers did not operate in asynchronous mode. The Mk.II versions do, but were not available when I wrote this Halide review.

"Suppose your USB port is 2.0 instead of the older 1.1 - makes any difference?"

No. As you wrote, USB2.0 is indeed backward compatible with 1.1. But the common USB-serial audio chips available are based on USB1.1.

John Atkinson
Editor, Stereophile