Bel Canto REFLink USB digital processor


In 1990, John Stronczer founded his company named after the virtuoso singing technique bel canto – Italian, "beautiful singing" – where the human voice is considered as an instrument.

On ReMusic virtual pages, we have already spoken of Bel Canto, reviewing the DAC 3.5 VB MK II and its power supply VBS1 (Virtual Battery Supply 1). They will be great supporting partners in the current test of the Bel Canto REFLink asynchronous USB converter.

The REFLink is an asynchronous USB converter sold by the Italian importer - Audio Point Italia – at a price of 1.495,00 EUR.

It represents the top model in the category, although Bel Canto offers also the Ulink and Mlink models at a price of 675.00 and 375.00 euro, respectively.


Maybe now you are asking to yourself: “What is an USB converter and which are the differences between a synchronous USB converter and an asynchronous one?”.

To answer the questions I asked my friend Luca “Don Luca” Pennacchioni, an electronic engineer very keen in high fidelity. He said: “In order to keep things simple, we won’t discuss here what terms like clock and jitter mean. Instead, we’ll focus on how USB asynchronous transfer works from a more practical point of view.

Let’s say that we are seating at a table and you ask me to pour you a glass of water. The glass is in front of you. I pour from the bottle the quantity of water that I think is sufficient. This is how isochronous USB implementations works. In the example, I represent the source, which could be a PC, a Mac or a CD player, and the customer represents the DAC. The source decides when and how much data have to be sent to the DAC. 

Now, back to the example. Instead of being me the one who decides when and how much water to put into your glass, the customer will tell me when to start pouring water into his glass and when to stop. This is how asynchronous transfers work. In the example, I represent the source and the customer the DAC: the DAC communicates to the source when and how much data have to be sent.


It’s simple, isn’t it? Then, why all this enthusiastic speaking on this new way of interfacing a source and DAC via USB?


Back to the example one more time. Let’s say that, as I’m pouring the water, at the same time I’m on the phone, with my foot I’m cleaning the floor and, thanks to the psychokinesis, I’m putting the dishes in the dishwasher. In a situation like this even making a simple action like pouring water into a glass can be a hard task. Therefore, some mistakes, like pouring some water out of the glass or putting too much or too little, are plausible. 

From the example, it is quite clear to understand that the source (a PC, for example) is acting as a ‘factotum’ and is doing several other things along with playing back music. Shutting down all the software, which is running on our platform it is often not enough to be considered a viable solution. There are hidden programs working underneath, known as demons or background services, and are vital for the correct functioning of the operating system. Therefore, they cannot be halted.

Hence, there is the possibility that the data transmitted could be, even in small and imperceptible ways, compromised because your computer is busy doing other thousand things while playing back your music.


The solution to the problem is the asynchronous USB connection. In this mode, the DAC tells the source when to send data. The computer needs only to be ‘listening’ in order to send the data when asked. This increases the precision of the data transmitted and decrease the jitter giving a boost in sound clarity and making it sound less ‘digital’.


Unlike isochronous USB, which being Plug'n'Play can work straight away when plugged in with no further actions needed, some asynchronous implementations need proprietary drivers. Mac OS X has exceptions: some asynchronous implementations do not need any added drivers thanks to Core Audio.


The reason behind needing a driver is simple: if I am in front of an empty glass with a bottle of water in my hand, my purpose is clear, but we need a common language to communicate to establish when and how much water the customer wants poured into his glass. This is why we need drivers. They are a set of information, which the computer uses to communicate with its peripherals.


While many manufacturers are making an effort to develop drivers for other operating systems in addition to Windows and Mac, other asynchronous USB chip manufacturers have left the Linux users empty-handed.

Before purchasing a new DAC or transport that uses an asynchronous USB interface, make sure your operating system is supported.


And now, for the billion dollars question: do asynchronous USB implementations ‘perform’ better than their isochronous counterparts?


There is no real answer.


On paper, asynchronous USB transmission is a clear upgrade from its isochronous counterpart, but in real life tests, it depends on varying factors.

I have listened to expensive, exceptional isochronous USB implementations, which put to shame many asynchronous, as well as affordable asynchronous implementations, which were on par with higher priced isochronous.

This technology is still young both in hardware and software form. There is a lot of room for improvement and, given enough time, it will probably surpass even the best isochronous implementations.


I always suggest listening to the DAC/transport in person before making a purchase, regardless of USB implementations.

This way you’ll get home with a piece of equipment which will serve you well for years and fill your life with wonderful music.


Well, now it is time to have a look at the website of Bel Canto and take some info on the REFLlink.


Among the most important things, we can find the LNS, Low Noise Supply, a dedicated power supply unit with high levels of isolation.

That offers low noise, high transient current and a high degree of isolation from the AC Line supply.

The REFLink is the only one, out of the three USB converters, with its own power supply unit. The Ulink and the Mlink use the USB input.

Another interesting thing is the ST Fiber, one of Bel Canto proprietary connection that can be used with the DAC 3.5VB MK II. Bel Canto states that this connection, matched with the ST Fiber cable, offers a high speed of data transfer and is the top in terms of isolation.


The REFLink can be used with Mac systems via USB 2.0 and has proprietary drivers for Windows. No clue of what can happen with Linux.

The REFLink operates at 16 or 24-bits at 44.1 - 48 - 88.2 - 96 - 176.4 and 192 kHz, everything commanded by proprietary 500 MHz dsp core.


All the devices by Bel Canto can read DSD files and here you can click on an interesting PDF file by John Stronczer about Optimal DSD Playback for Bel Canto Design DACs.


The time has come to remove the REFLink from the packaging.

The cabinet is the same as for the DAC 3.5 VB MK II: 1 cm of aluminium front fascia with the logo on the top of the panel.

The chassis is in solid black stainless steel with a U-shape lid.

The dimensions are half size a common cabinet and the DAC 3.5 VB MK II, with the REFLink on its top, looks gorgeous.


The available colors are silver and black.


On the front panel, we find the eight digit displays and a knob to control the sample rate, the firmware version and, if you like, to disable the display.

On the rear panel are the USB input, the AES/EBU, Spdif and ST Fiber outputs.

Left to the outputs are the on/off switch, actually not very handy but aesthetically well thought for the front panel, and the IEC socket.

The system is supplied with a low medium quality power cable, the SF fiber cable and a BNC/RCA adapter.


After having downloaded the Asio drivers for Windows on my PC, I cross my fingers and… immediately everything works! No conflicts with my PC and Foobar, which recognizes immediately the drivers. A user-friendly system indeed!


Lets’ start with the first set up: DAC 3.5 VB MK II, used also as preamplifier, REFLink, my audio PC, Vandersteen 2ce loudspeakers and the trusty Adcom 555.

I will use the ST Fiber input and cable.


I connect my PC to internet so to download the Playstore Foobar2000 controller, an Android app to control Foobar with my mobile phone.

Good. From my couch, I can control all the operations: preamp and DAC with my Bel Canto remote and Foobar with my mobile.

I can also play on the phase using the dedicated button on the remote of the DAC!


First record: Black Album by Metallica.

The impact is remarkable and the soundstage is wide.

The punch is strong and the music is really transparent. The take, however, is not of audiophile quality and the REFLink reminds that constantly.

The dynamic excursions are well represented, without running after or before the sound message.

What it is not fully convincing is the high range, since it is too in evidence and hyper-detailed. I change loudspeakers with a DIY three-way Scan-Speak.

Everything now is more balanced and with the track Guarda che Luna, performed by Petra Magoni, accompanied by Ferruccio Spinetti, the voice is very balanced and the veil that darkened the sound has fallen. Everything is clear, transparent but not whipping and hyper-realistic.


Now it is time for the saxophonist Jan Garbarek. In all the tracks I played, the mid-range is slightly rearward. So, I connect my Audio Research LS8 preamplifier and, maybe thanks to the tubes, things are better.

A mid-range that is very fluid and rich of harmonic underlayer. The listening pleasure is higher also at high volume.

Next track is Sam Mclain, Give it up for love, and it is immediately evident the good micro-dynamic of this object, together with the great separation of the instruments. It is a real pleasure to listen how the Hammond organ has been reproduced.

Regretfully, I decide to test other connections between REFLink and DAC. The outcome is a small loss in detail and a decrease in dynamics.


Another match that I have tested is REFLink Mac, using JRiver as software on the suggestion of Mr. P.J. Zornosa and, I must say, it is a real good match. Sometimes superior to Windows that I usually prefer.


A recap

Timbric: natural, not artificial, capable of making the music very realistic.

Dynamics: great performance, capable of giving back in a quick way the dynamic excursions, just a bit excessive in the low range.

Image: very wide and with good depth, great the three-dimensionality and excellent separation.

Manufacture and packaging: solid, high quality materials, rational layout, wide use of SMD.

Handy with a strong double packaging.

Price/quality ratio: in line – alas! – with the competitors



I do not like the USB converters because of today there are more performing listening modalities. However, since this connection is largely used, if you like something of good level, the REFLink is one of the few possible answer that the market can offer.

Well-advised and logic the fact of proposing it aside and not integrated into the DAC. So the purchaser can choose model, costs, etc.

The REFLink is a well-made and beautiful object, mostly if matched with other Bel Canto products.

Matched to the DAC 3.5 VB MK II and connected via ST Fiber, it has shown a great synergy. This is why I suggest pairing it with this last one.


Official technical specifications:

Input: High Speed USB type-B receptacle

Output: Coaxial SPDIF on BNC 75Ω, Balanced AES on XLR 110Ω, LightLink ST Fiber

Dual Ultra-Low Phase-Noise Clocks: Jitter <70Femtoseconds RMS, 100Hz-1MHz

Supported sampling rates: 44.1kHz, 48kHz, 88.2kHz, 96kHz, 176.4kHz, 192kHz

Supported word lengths: up to 24-bit


Native MAC USB 2.0 compatible on OSX 10.6 and later

Custom Windows USB 2.0 driver Win 7, Win 8, and XP

Driver appears as Bel Canto uLinkUSB2.0 select as default playback


Power Usage On: 3W

Power Usage Off: 0W

Power Requirement: 120VAC/60Hz or 240VAC/50Hz set internally

Dimensions: 8.5”x3.5” x12.5” (216mm x 318mm x 88mm) WxHxD

Weight: 14lbs (6.5kg)

Official Italian dealer: to Audio Point website

Official current price in Italy: 1,495.00 euro

Associated equipment: to Francesco Taddei's equipment

by Francesco
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