Bel Canto uLink USB-S/PDIF Converter
Device Type: USB-S/PDIF Converter
Input: USB Audio Class 2.0 (Type B)
Output: Coax S/PDIF (RCA), ST Fiber
Dimensions (W x H x D): 4 x 1.2-inch x 4.75
Availability: through authorized dealers
The Bel Canto uLink asynchronous USB-S/PDIF Converter works the same as most other like-devices taking the USB output from your computer and turning it into S/PDIF data your DAC can connect to but it adds an interesting wrinkle to the proposition by including a glass ST Fiber output. The interesting thing about an ST Fiber connection beyond its inherent immunity to electro-mechanical noise is length—you can run an ST Fiber connection over 100 meters.
Of course your DAC needs to have a compatible ST Fiber input and I don't have such a DAC. Bel Canto's own DAC3.5VB mkII comes so equipped and there are others on the market including a number of DACs from Wadia. But seeing as I am ST Fiber-less on the input side, this review will focus on the S/PDIF BNC 75Ω output of the uLink connected to the Mytek Stereo 192-DSD DAC using the included BNC/RCA adapter.
The uLink supports up to 24/192 data courtesy of its asynchronous XMOS-based USB receiver and the uLink also gets its power from the USB bus which is galvanically isolated from the audio circuit. Windows-users looking to take advantage of the uLink's greater than 96kHz abilities need to download and install Bel Canto's Windows driver. Mac users are ready to roll.
According to Bel Canto, an important difference between the uLink and their lower-priced mLink ($375) is the uLink's pair of Crystek Corporation Standard Clock Oscillators, or according to Bel Canto "Dual Ultra-Low Phase-Noise Clocks, Ultra-Low defining the difference between the mLink and uLink’s clocks". Bel Canto also offers the REFLink ($1,495) which adds among other things its own AC power supply, the same Low Noise Supply as found in the Bel Canto DAC2.5.
The uLink is a small aluminum box with black plastic end bumpers. There's a green LED that lights when the device has power and its inputs and outputs are on all the same side. Underneath are four LRF (little rubber feet) and the entire package is designed and manufactured in the USA. I used my MacBook Pro running Pure Music and an Audioquest Carbon USB cable to connect to the uLink.
One Smooth Customer
The uLink is one smooth customer. If there's one thing to take away from this review, it's that. If you own a non-USB DAC that you otherwise like and want to be able to play your computer-based music through it, the uLink or a like-device is in the cards for you. If you want that new piece of gear to impart a smooth and sonically beneficial sound to your playback chain, the uLink may be the card for you.
I provided some comments and comparisons in my review of the Musical Fidelity V-Link192 ($249) but I'll repeat myself—the uLink sounds more fluid and natural as compared to the V-Link192 which sounds fluid and natural when you listen to it by itself. Compared to the Mytek's own USB input, the uLink helps smooth things out and presents an easier to listen to presentation with less bite. There's no reduction in resolution or detail, just a relaxing of edges. There also seems to be a slight tightening of bass response making bass lines easier to follow. These are all subtle differences as opposed to night and day differences and the degree to which the uLink will offer an improvement will vary from DAC to DAC.
Since the uLink gets its power from the USB bus whereas the more expensive REFLink gets its power from its own AC power supply, I figured it would be interesting to try the iFi iUSBPower ($199) with the uLink and see if it offered any improvement. The iUSBPower [see review] is a clever device that sits in between your computer and DAC or USB-S/PDIF converter and provides 5V of clean power while also helping to remove any USB-based noise upstream. With the iUSBPower in my system, I noticed a lowering of the noise floor. Most striking were the more delicate sounds like brushes on cymbals, better defined spatial queues, and more dynamic impact. Again we're not talking night and day differences rather comparative differences but if you are looking to squeeze every last drop of musical goodness from your uLink, you may want to give the iFi iUSBPower a try.
If the Shoe Fits
With any device like the Bel Canto uLink your specific system situation will color your impressions of it one way or another. It would seem to follow that if you find your current USB DAC to be a bit too aggressive, the uLink may help tame it. If you're looking to get into computer-based audio and your DAC does not have a USB input or if your DAC's USB input does not handle 24/192 data but its S/PDIF input does, the uLink offers a very non-digital, good-sounding option to get you up and running in no time. And if you own a DAC with an ST Fiber input and are in need of a longish connection between your computer and DAC, what on earth are you waiting for?
Also on hand and in use during the uLink review: Musical Fidelity V-Link192