ExaSound Audio Design e20 Digital-to-Analog Converter


Equipment report
Digital-to-analog converters
ExaSound Audio Design e20
ExaSound Audio Design e20 Digital-to-Analog Converter

Compared to full-size DACs, the silver (black is not available) aluminum e20 is svelte. Its 6.5" x 2.2" x 7.9" chassis won’t take up much space on your equipment rack, nor will its 1.653 pounds put much strain on the shelf. The low weight results in part from an external in-line power supply. The e20 is well-built and attractive, but probably wouldn’t be characterized as audio jewelry, which makes sense to me; you’d probably pay twice as much for a full-size chassis with a thick faceplate.

On the front panel are five silver buttons, a window showing what the e20 is doing, and the 1⁄4" headphone jack. The buttons are (from left to right) the power switch, a set-up menu, the input selector, and volume up and down. The volume control works on both the headphone amplifier and the e20’s outputs. The input selector switches among the three digital inputs: USB, S/PDIF on coaxial, and S/PDIF on TosLink (optical).

The status window has a two-line blue display. While easily readable from directly in front of the e20, there’s no way you could read the display from your listening chair across the room. (Well, I guess you could use binoculars.) The display’s top line tells you which input is selected, the type of signal (PCM or DSD, with automatic switching) coming into the input, and the sampling rate playing through that input. The bottom line tells you the input is 2-channel and shows you the volume level. When you first turn the DAC on, the volume level is set at -40dB, to prevent overloading your amplifier and speakers (and ears). You can adjust the volume setting in 0.5dB increments.

A poorly implemented digital volume control can degrade sound quality, so I asked George Klissarov, President of exaSound Audio Design, to describe the e20’s: “The volume control of the e20 is implemented by the ES9018 DAC chip. It is at the borderline between the analog and the digital domains. We send volume commands to the chip, and it creates lower voltage on the analog side. This way there is no loss of bit-depth, and we avoid the usual issues with noise when analog volume controls are used. This solution provides the ultimate flexibility.” Bottom line: The e20’s volume control won’t degrade your sound.

The back panel of the e20 is small, so it’s chock-full of input and output jacks. Besides the three digital inputs, there’s an input jack for power from the in-line power supply. Signal output is available on both balanced (XLR) and unbalanced (RCA) jacks.

A small toggle-switch lets you isolate the ground from the computer attached to the USB input. Normally in the isolated position, the switch may be set to connect the ground if there are hum or noise problems. To save space, the USB input jack is a mini-USB jack, rather than the usual USB Type B jack found on most DACs. That means many USB cables won’t fit. Fortunately, exaSound provides a USB cable with a mini-A USB connector on one end and a Type A connector (the type that goes into your computer) on the other. Such cables should be available at your local computer store, or if you order a cable from a cable manufacturer, there should be no problem getting one with the mini-USB plug on one end.

The simple remote control duplicates the e20’s input-switching and volume-control functions. That’s enough to make it feasible to use the e20 as a system preamp, if you only have digital sources. The remote looks a little like a Classic iPod, with a circular dial containing most of the controls. That’s not surprising, since it’s an Apple control. You can reprogram the e20 to use other IR remotes, if that would be useful. The remote controls volume, input, and muting.

The e20 is sold direct with a short one-year warranty, but has a thirty-day return policy (so you can try it out before you decide to keep it). For those, like me, who lament the demise of so many brick-and-mortar dealerships, a return policy like this seems like the next best thing to a dealer loan.