The Trends Audio UD-10.1 USB audio converter is simply a very cool product. The UD-10.1 is not a standard Digital to Analog Converter * (DAC). Rather the UD-10.1 is a digital I/O interface that takes a computer's USB output and passes the signal through unchanged to the DAC of your choice via the interface of your choice. What make this product so cool is its versatility. Everyone has a USB port on their computer. Not everyone has a USB DAC. Many components have an optical input, but not many computer have an optical output. The UD-10.1 solves the issue with its plethora of digital outputs. If you have a dedicated external DAC the chances are almost 100% that the UD-10.1 has the right type of output for the unit. The same goes for those of you with AV receivers. During the review period I connected my Mac Pro to my Berkeley Audio Design Alpha DAC with optical, coax, and AES cables from the UD-10.1. The connections looked like this crude diagram:
Mac Pro >> USB output >> UD-10.1 >> Toslink & Coax & AES >> Alpha DAC
Trends Audio built the UD-10.1 with good quality components and audiophile applications in mind. Many of us are aware how critical a component's power source is to achieving good sound quality. Trends Audio understands this and created a rechargeable battery power supply for the UD-10.1. This option is available for an extra $13. If convenience is more important to the listener, the UD-10.1 can also run completely from power supplied over the USB cable from the computer. Trends Audio also used proprietary dual power regulation circuits instead of the standard 5V USB bus power. Whether the power comes from battery or the USB bus it is regulated before hitting the ICs, but Trends Audio recommends using the battery option and I won't disagree with that recommendation. The UD-10.1 is equipped with a Burr Brown PCM2704 IC for USB audio conversion to the many output options. Following the audio path further downstream Trends Audio implemented proprietary impedance matching circuits for the AES/EBU (110 ohm) and Coaxial (75 ohm) digital outputs. For the readers not interested in the fine details all you need to know is the UD-10.1 requires no software installation on your computer. Plug this thing in, select it as your default audio output device and start rocking.
At $169 and a fairly modest build quality the UD-10.1 is more about sound quality than aesthetics and heft. The UD-10.1 is limited to 16 bit / 44.1 kHz like most USB audio devices available. Fortunately the vast majority of content available at the moment is still 16/44.1. Dropping $169 in the interim between redbook content and high availability of greater resolution is really a no-brainer. In my system the UD-10.1 performed pretty well. The sound was actually much better than I thought it would be considering the cost and flexibility of this component. Granted low cost does not equate to low performance, but very low cost can certainly be one indicator. The only two negative aspects of this USB converter are a somewhat compressed and thinner sound. This was evident when comparing the UD-10.1 directly with the Lynx AES16e ($700) digital I/O card. It is very possible that someone without the ability to A/B the UD-10.1 with a card like the Lynx AES16e would never notice this slight compression and thinness. It is also quite possible that giving these two negatives so much press is exaggerating the actual sonic impact a bit. The difference between each of the outputs on the UD-10.1 was negligible. Since the UD-10.1 sends audio to all outputs all the time it was very easy during the review to compare the outputs by switching inputs on my Alpha DAC. Scrolling through the inputs of my DAC revealed no sonic differences that I could consistently identify in a blind A/B/X test. The most important thing I looked for with the Trends Audio UD-10.1 was its ability to pass the data in a bit perfect stream. Every output on this device passed the HDCD test with flying colors. If a component can't pass an untouched audio signal it is impossible to improve imperfection further downstream. Fortunately the UD-10.1 is perfect in this regard.
With the UD-10.1's release there are no longer any excuses to put off setting up a music server. Everyone has a computer and everyone has a stereo. The UD-10.1 is the magic component to bring the two together while avoiding the dreadful internal digital to analog converters. I've never heard a computer with an acceptable built-in D to A converter and I don't see the quality of these DACs changing any time soon.The Trends Audio UD10.1 is not in the same class as the Lynx Studio cards, but it's performance is worth quite a bit more than its very inexpensive price.The UD-10.1 provides the capability for many people to finally connect their computer to their stereo without major sonic degradation. In my opinion that is worth the price of admission and then some. Give the UD-10.1 a shot and I'm willing to bet your physical media addiction will come to an end and you'll be downloading albums in a matter of hours. Computer Audiophile conclusion = Add To Cart.
Audio Outputs: Digital and analog outputs RCA, BNC and XLR connectors
Headphone volume control is provided by the PC or Mac
Analog Outputs: Burr Brown PCM2704 digital to analog converter (DAC)
Linear-regulated power for all analog paths
Signal-to-noise, Dynamic Range: 98dB
THD+N: 0.006% (RL > 10 k, Self-Powered)
SNR: 98 dB
PO: 12 mW (RL = 32)
Digital Outputs and Inputs: Optical, Coax, BNC, and XLR digital connectors
Linear-regulated power for digital paths
Linear-regulated power for all clock paths
4 pin high accuracy crystal clock (±10ppm)
Standard IEC-958 (S/PDIF) or AES/EBU encoding
RCA connector: 75 ohms
BNC connector: 75 ohms
Optical connector: TOSLINK
XLR connector: 110 ohms
Sample rates: 32, 44.1, 48 kHz
Audio format: linear PCM, 16 bits per sample
Audio Formats : Lossless Formats: FLAC, WMA Lossless, Apple Lossless or other
Uncompressed formats: WAV, AIFF, PCM or other
Compressed formats: MP3, AAC, Ogg Vorbis, MP2, MusePack, WMA or other
System Requirements: All systems: 256MB RAM with 30MB hard disk space
Windows OS: Windows NT/2000/XP/Vista or later
Macintosh: Mac OS X 10.3 or later
Linux, PC LinuxOS 2007, Fedora core 7, Ubuntu 7.04 or other
Power Supply : USB Bus Power or
External power: DC 4.35V – 5.25V(max): (e.g. AA size rechargeable battery 1.2V x4=5V, don't use normal batteries with 1.2V x4=6V, it would be too high for safety and good sound performance)
Dimensions: (W)76mm x (H)46mm x (D)114mm [case only]
(W)76mm x (H)46mm x (D)128mm [incl. sockets & knob]
Case: Stylish iron-gray aluminium
Accessories: 1.5m type A to type B cable x 1
Mini Jack to 2 Phono Sockets Adapter x 1
Warranty Card x 1
Optional Accessories : Trends UD-10.1 Charger Kit : AC Input: Universal AC 100V-240V / 50~60Hz
DC Output: DC 5V /0.5A
The package includes charger, battery box and 4 AA size rechargeable battery (1.2V x4=5V),
Power on, but no battery connected : Black color
Charging: Red color
Charged/Float Charging: Green color
Dimensions: (L)110mm x (W)80mm x (H)60mm
Warranty: One year parts and labor.
Regulatory Compliance: CE FCC
Price - $169 UD-10.1 and $13 for the battery pack and charger.
More information about the UD-10.1 and Trends Audio is available at http://www.trendsaudio.com
Associated Equipment: Mac Pro, Lynx AES16e card, Kimber USB cable, Berkeley Audio Design Alpha DAC, Benchmark DAC1 PRE, Kimber Select cable, Avalon Acoustics speakers, Focal Electra Be series speakers, McIntosh tube amplification, Virtual Dynamics power cables, Richard Gray's Power Company cables.
* See comments 2 and 3 below explaining why I don't consider this component a standard DAC.