Monday, September 29, 2014

Totaldac USB cable / filter


Totaldac is a company based in France that has been creating a lot of buzz lately with its DAC designs.

The founder of Totaldac is Mr. Vincent Brient, a professional engineer who has worked in a variety of industries before founding Totaldac. Looking at the hand built R2R circuit (utilising 0.01 % precision Vishay resistors) inside his DAC, a certain amount of respect is due for Mr. Brient.


The Totaldac USB cable / filter is stated to improve the sound of any DAC or music server utilising a USB connection. A sealed aluminum box contains more than 30 components, to provide filtering for digital pollution coming from a computer or music server. The box will even protect your DAC from an over voltage situation.

The Totaldac USB cable will operate under both USB 1.0 and 2.0 modes, and transmits bit-perfect data. No drivers were needed in my tests, under both Windows and Mac environments.

Mr. Brient kindly agreed to answer some questions I had about his cable and some other general questions. The questions and answers are reproduced in verbatim below :-

Q1. The totaldac usb cable/filter is described as containing "high performance filters to suppress digital pollutions coming from the computer or the music server.". Are both the data and power lines filtered ? Does the box provide galvanic isolation from the computer ?

A1. It filters both data and power. There is no galvanic isolation as this doesn't exist for high speed USB. It exists only for old non-asynchronous DACs with a 12Mbit/s USB bit rate, unable to do 192KHz/24.

Q2. The totaldac cable uses a single cable instead of the increasingly popular route of using separate cables for the data and power lines. Do you have any thoughts on this ?

A2. The filter box is placed very close to the DAC connector, so the cable separation is no critical. The long part of cable is before the filter.

Q3. Some audiophiles feel that USB (even if asynchronous) does not sound good as other connection methods like AES or coaxial. Many are using separate USB/SPDIF convertors, claiming better sound compared to direct hookup to their DAC's USB input. Do you think think this approach has any merit ?

A3. All computer approach need a computer bus to output the digital audio signal. USB, PCI and so on, all have the same difficulty due to the clock and pollution of the computer. There is no computer with true native spdif output, then can only fill and asynchronous fifo, just like the USB does, even if the fifo can be in the processor itself.

USB, even asynchronous, is a sensitive link, this is why the filter helps. For the best sound my customer use the d1-server using the USB cable/filter for the internal loop, then the signal is rebuilt again in AES-EBU in the asynchronous reclocker, then goes to the DAC via AES-EBU.

A computer straight to a USB DAC is not the best way.

All in all the difficulty is not especially the USB, it is the computer for audio, but optimisation are possible, I think that now the d1-server with its USB filter is better sounding than a CD drive.

Sound Quality

The Totaldac USB cable / filter was deployed in a number of situations, similar to my review on the Astin Trew Concord Powered USB cable system. The supplied review sample was 2 m in length.

Tonally, the Totaldac was very different from the JCAT or the Wireworld Platinum Starlight cables which I had on hand. The Totaldac had a richer, warmer and more organic balance.

Bass lines had a good deal of weight and bloom, positioned between the hard hitting Wireworld, and the neutral JCAT. I found the bass to be subjectively "wetter" and more rounded than the Wireworld.

Midrange had a slight prominence and projection to it, with vocals being pushed forward slightly in the soundstage compared to both the Wireworld and JCAT. There was also a pleasing smoothness and warmth. A little bit of texture was sacrificed in favour of an absence of sibilance on female vocals. 

Treble presentation varied depending on where the cable was deployed. On my main system, linking my Mac Mini to my Calyx Femto DAC, I felt that the treble was almost as extended as the JCAT, but with a slight emphasis towards the initial transient of the instruments compared to the decay and room ambience. The treble was slightly softer in quality, wth the Totaldac linking my Macbook Pro to my Antelope Zodiac Gold DAC, and even more laidback when I deployed the cable to connect bus powered devices like my Calyx Coffee DAC / headamp, or my Bel Canto uLink USB / SPDIF convertor.

From a staging and imaging perspective, the Totaldac had a grander presentation, with a larger sense of scale and bigger image size. The Wireworld, and to a greater degree, the JCAT had more pinpoint imaging and a more distant perspective. 

The contrast between the Totaldac and Wireworld was most stark on my Calyx Coffee. The Totaldac was sumptuous and inviting and almost analog like. The Wireworld was punchy but aggressive on the top end, almost to the point that listener fatigue set-in after a few minutes of listening. 

The Totaldac reminded me in many ways of my Lite DAC-AH DAC, a non-oversampling design that utilised 8 paralleled TDA1541 chips. Coincidence ?


I found the Totaldac to be a more easy going cable compared to both the Wireworld and JCAT. As cliched as it may sound, the Totaldac would likely please the listener who is seeking a more analog like presentation from their computer music. 

The choice of cable would depend very much on the tonal balance sought, and choice of music.

I liked the Totaldac very much - it was the house guest with impeccable charm and manners.  I would put it at the top of my audition list if I was seeking a USB cable with a fuller, smoother and fluid presentation - Highly Recommended.

The review sample was supplied by Mr. K.M. Poon of Horizon Acoustics, the Singapore distributor for Totaldac.

I wish to thank both Mr. Poon of Horinzon Acoustics and Mr. Brient of Totaldac for making this review possible.

Horizon Acoustics

144 Upper Bukit Timah Road
#03-15 Beauty World Centre
Singapore 588177
Tel : 91259149
Email :
Website :


Email :
Website :


0.25m or 1m: 360euros incl VAT in the EU, 330euros excl VAT outside of the EU.
2m: 390euros incl VAT in the EU, 360euros excl VAT outside of the EU.

Monday, September 1, 2014

Astin Trew Concord Powered USB Cable System


The Astin Trew Concord Powered USB Cable System (hereinafter referred to as the "Concord USB") consists of a high quality 5V power supply design based on the patented Never Connected circuit (as seen on Trichord Research and Michell Engineering products), and a cable of your choice to split the data and power lines. You can read more about the Never Connected Circuit at

Two cable options are offered. The first option is a complete USB cable solution - the source end has two heads - one end plugs into your computer / streaming device, and the other end into the power supply box. The destination plug goes into the USB socket of your DAC. The second option consists of a USB B type plug with a piggy back female socket (to use your USB cable of choice), and a second cable to connect to the power supply.

According to Astin Trew, the Concord USB boosts performance to your computer music setup by supplying your DAC (for bus powered DACs), or the USB integrated circuit with a high quality power source. Astin Trew claims that about 80 % of DACs on the market should benefit.

The power supply box couldn't be simpler. An IEC socket permits use of detachable power cords, while a toggle switch switches the device on and off. The rear panel has a proprietary socket to supply the power to the USB cable. The front panel has a solitary LED to indicate power status.

I would really have liked the power supply to offer a USB Type A socket. This would allow the Concord USB to be used with the growing number of twin headed (with power and data lines separated) USB cables out there.

Sound Quality

I was supplied (at my request) with the piggy back USB cable in order for me to use my own USB cables. I tried the Concord USB with three different equipment, 1) an Antelope Zodiac Gold DAC,  2) a Bel Canto uLink USB/SPDIF convertor, and 3) a Resonessence Labs Herus DAC / headamp.

The Antelope has its own power supply, which also feeds its USB input circuit board. In fact, the Antelope is listed by Astin Trew in the supplied user manual as not being able to benefit from the Concord USB.

Notwithstanding Astin Trew's advice, the Antelope gained a small but easily discernible improvement with the Concord USB paired with my Wireworld Platinum Starlight USB cable.

"Live at Blues Alley" by Eva Cassidy is one of my favourite albums. With the Concord USB, the soundstage deepened, and the acoustics of the venue improved in the conveyed sense of air and liveliness. Eva's vocals came through in all it's glory - coupled with a subtle improvement in detail and authority. These improvements were also heard on a wide variety of material. Piano notes in particular, had tighter focus and better attack.

However, the real shocker came from switching off the Concord USB. The Antelope only needed momentary power to be supplied over the USB cable to establish handshaking. After that, power could be removed without incident. My system immediately moved up a notch in dynamics and energy. There was also an increase in top end air and decay. The soundstaging presentation moved a bit forward, which was not really my preferred perspective though.

Moving on, the Bel Canto and Resonessence Labs both draw their power from the computer. Would both benefit greatly from the Concord USB ? I was especially interested in how the Bel Canto would fare. Bel Canto claims that the uLink filters the noisy computer supplied power with L-C filters and multiple dedicated supplies.

The Resonessence offered only slight benefits in utilising the Concord USB. You could argue that there was a slight lift in transparency and dynamics. Truth be told, the differences were quite subtle.

The Bel Canto turned out to be a wholly different story. Going back to "Live at the Blues Alley", the soundstaging deepened considerably. Eva took on a warmer and less harsh tone, and there was an impressive improvement in the system's ability to convey the details and texture of her voice. Notwithstanding its power filtering stages, the performance of the Bel Canto was lifted to such a great degree that I could not help but wonder - would the paired combo would be able to outperform Bel Canto's REFLink, its top model USB / SPDIF convertor ? Then again, the REFLink is cheaper if you factor in the additional cost of the Concord USB.


The Concord USB shone most on bus powered devices. It was a pity that I did not have other USB powered devices to try, especially a device that would have justified the Concord USB's cost.

The benefits with self powered devices were on a more subtle yet discernable level. Ironically, in the case with my Antelope DAC, the best results came from powering down the Concord USB, which suggests that the most benefit was obtained by simply stripping out the bus power. In that respect, I would have loved to see Astin Trew offer their cable for sale separately, terminated with either a DC plug or USB Type A plug for maximum compatibility.

From a value perspective, the Concord USB is undeniably expensive. There are a number of other competing products on the market that offer similar solutions at significantly lower cost. Nevertheless, the Concord USB is still worth investigating. Especially so if your system cost justifies it, or you are seeking to squeeze the very last ounce of performance of your USB DAC.

The Concord USB Cable System costs SGD 1,400 and is available locally from :-

Sky Audio
Block 621, Bukit Batok Central
Singapore 650621

A word of thanks goes out to Steve Sai of Sky Audio for supplying the review set.