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 http://www.never-connected.com/concept.html
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.
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 :-
Block 621, Bukit Batok Central
A word of thanks goes out to Steve Sai of Sky Audio for supplying the review set.