Review: Gefen High Resolution USB to Analog and Digital Audio Decoder

GefenUSBtoAudio-0115I’m an audiophile, but I’m a frugal audiophile. As delightful as big-ticket stereo equipment is, my Scots heritage and its accompanying frugality informs my preferences.

In short, I get thrilled by equipment that delivers best bang for the buck.

Gefen is best known as a maker of video dongles for a variety of streaming and distribution solutions. Since I have a well-documented passion for dongles, widgets and problem-solving devices I’ve used and tested a broad variety of Gefen hardware in the past, often with a broad variety of results: from poor to excellent.

With that breadth of prior experiences, I endeavored to maintain an open mind.

The company’s High Resolution USB to Analog and Digital Audio Decoder is intended for users who want to listen to streaming digital media from their PC or laptop, connected to their audio system, and who want to experience a higher degree of musical fidelity than they’d get from the headphone jack output to a 3.5mm to stereo RCA adapter cable.

The decoder supports digital audio up to 24 bits and 192kHz sampling rate coming from the USB port of a Windows PC or Mac, and converts it to both optical digital (TOSLINK) and analog left/right audio. The outputs of the decoder can be connected to A/V Receivers, analog pre-amplifiers, or headphones. It should be noted that your audio output must be configured to output high resolution, two-channel LPCM audio through USB. The decoder does not support Dolby Digital or DTS.

gtv-192kusb-2-adaud-back-0115In my case, in my home office, I connected the decoder to my laptop (a Dell 14-inch, running Windows 7, in case you’re interested) via USB, and then ran the analog L/R outputs first into a Ground Loop Interrupter from Monoprice and straight into the L/R inputs of my home office sound system: a Speakercraft Big Bang BB2125 (two 125-watt ouputs, get it? Speakercraft always did clever nomenclature like that) and a pair of battered and well broken-in first-generation PSB Alpha bookshelf speakers, on isolated metal floor stands.

“Wait,” you say, “Back up. What was that about something from Monoprice!?”

It’s called a Ground Loop Interrupter. Because it’s my home office, and because all the 120-volt outlets in the room are on the same circuit, the interplay of power and data cables connected to laptop, printer, scanner, hard drives and AV equipment, even with the use of a filtering power bank causes a 60Hz hum to manifest from my amplifier to my speakers.

After much unplugging and replugging of every cable and cord in the room, only for the 60Hz hum to reappear at random sometimes days later, like electricity, I took the path of least resistance.

Like Alexander the Great cutting the Gordian Knot in half with his sword, I fixed my system’s intermittent hum with a fourteen dollar mail-order part.

That doesn’t make me a philistine, it makes me smart.

Out of the box, the Gefen decoder is compact, about the size of an Apple TV unit, and very light. Unlike more expensive DACs, Gefen doesn’t try to bamboozle your senses by packaging the DAC circuits in CNC machined metal billet with fancy engraving.

It’s a box. Signal goes in. Signal goes out. Everything else in this business is marketing and window dressing.

The decoder is powered by the 5V input from the USB source connection, which is smart: one less detail to fuss over.

192k_info1-0115Apparently the decoder is totally plug and play for Mac users, but since I’ve got a Windows laptop I had to download the USB drivers from Gefen’s website, which generated the only real snag in doing this review.

While unpacking the USB driver and installing it my laptop froze up and had to be hard booted. Twice.

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In all fairness I cannot, with a scientific mind, blame that entirely on Gefen and its software. Notwithstanding any sarcastic Tweets I may or may not have sent at the time, my elderly laptop and my tendency to have way too many tabs open at once could easily have been to blame.

Once installed, right clicking on the speaker icon on your task bar will allow you to open the window to “Speaker Properties,” which allows you to toggle the sampling rates that the decoder will work at, from 16-bit, 44,100 Hz (CD Quality) to 24-bit 192,000 Hz.

192k_info2-0115I picked a selection of tracks from my iTunes library, specific ones that I’m deeply familiar with, and selected for their distinct lows, mids and highs:

Granted there was no option to do blind-listening so bias pertains, but toggling between 16-bit, 44,100 Hz (CD Quality) to 24-bit 192,000 Hz output on repeated listening of each track demonstrated noticeable sonic improvements when on the 24-bit 192,000 Hz output: richer lows, fuller highs, and more involved, encompassing soundstage to the two-channel mix.

I’m fairly jaded as a listener, but listing to some old favorite tracks through the Gefen decoder had me hearing details to the music that I’d not noticed in a long time. It definitely enhanced my listening enjoyment. Considering how much time I spend sitting at my desk working, that’s a huge plus.

The bottom line is that in the hi-fi marketplace DACs abound, and are available at prices that range from frugal to eye-watering. Not only is the Gefen decoder the least expensive DAC I’ve listened to, I’d rank it as one of the best, certainly on a pound-for-pound basis.

If you like audio and want to improve what’s coming out of your iTunes collection for the cost of reloading your Starbucks card you’d be hard pressed to get more bang for your buck.

The High Resolution USB to Analog and Digital Audio Decoder’s features and specs: if you like that sort of thing:

  • Accepts high resolution digital audio from a USB source, and outputs digital audio and analog audio
  • Accepts up to 24 bits of uncompressed 2-channel LPCM digital audio at 44.1, 48, 88.2, 96, 176.4, or 192 kHz sampling rate
  • Outputs 2-channel LPCM digital audio up to 24 bits and 192kHz
  • Outputs 2-channel analog audio via L/R RCA outputs and 1/4-inch headphone jack
  • Allows listening to locally stored or streaming digital media from a PC or MAC using an AV receiver, analog amplifier, or headphones
  • LED status indicators for power/streaming and sampling frequency
  • 1/8-inch to 1/4-inch (3.5mm) headphone plug adaptor included
  • Specifications
  • Audio Input Connector: (1) USB Mini-B
  • Audio Output Connectors:
  • One TOSLINK (optical)
  • One L/R analog audio (2 x RCA female)
  • One 1/4-inch stereo headphone jack
  • Power/Streaming indicator: (1) LED, blue
  • Sampling Frequency indicators: (6) LEDs, blue
  • Signal-to-Noise Ratio: 110 dBA
  • Frequency Response: 10Hz – 20kHz ± 0.1 dB
  • Total Harmonic Distortion (THD)+N: <0.02% 1 kHz, 2Vrms
  • Operating Temperature: +32 to 104 °F ( 0 to +40 °C )
  • Operating Humidity: 20 to 90% RH, no condensation
  • Storage Temperature: -4 to +140 °F ( -20 to +60 °C )
  • Storage Humidity: 0 to 95% RH, no condensation
  • Power Consumption: 2.5W (max.)
  • Dimensions (W x H x D): 3.4″ x 1.3″ x 3.4″ (86mm x 34mm x 86mm)
  • Shipping Weight: 1 lbs (0.45) kg
  • USB Driver :
  • High Resolution USB to Analog and Digital Audio Decoder Driver version 1.56
  • SKU:   GTV-192KUSB-2-ADAUD
  • MSRP: $49.99, direct from Gefen.com