One system setup for this review revolved around the following gear:
Mac Mini with iTunes or Amarra to the e22
TEO Audio Liquid Pre (in comparison to the e22’s preamp function directly to the amplifier)
Silnote Audio Cabling throughout
The exaSound Audio Design e22 is intuitive and simple for the owner to use. When the signal is applied to the e22’s circuitry it indicates the bit depth and clock frequency; there is no function for selecting alternative filters – you get what you get; but what you get is intuitive. Not being loaded down with unnecessary functions, it is easy to maneuver either by using the front face controls or by remote control. I encountered only one anomaly when using the e22, and it pertained to the supplied Apple volume control.
As I set up the volume of the system I was forced by the nature of the rig to work with four separate attenuation controls; the computer’s output, the TEO Audio Liquid Pre’s volume control, the e22’s preamp function, and the slider volume control of the Apple iPad’s Remote app. I was very grateful that the treatment of the level in the e22 is in the digital domain. I intended to put the computer’s output on max, but when I attempted to use the Apple remote control to command the e22, the Mac Mini responded in unison! There was a doubling of the output, or halving of the output as I raised or lowered the volume, as both devices were adjusting. Also, there was an annoying digital alert tone rising or falling with volume according to each adjustment as the computer alerted me to the fact that I had played with the level! I had to manually adjust the volume of the Mac Mini and the e22, and ignore the Apple remote supplied by exaSound to avoid the irritation.
This was not a major inconvenience for me, as I controlled the listening level through the iPad, but I would assume it to be a major inconvenience if I was using the supplied Apple remote by itself. Perhaps this is one reason why an alternative remote is offered by exaSound, as it likely would resolve the issue. Aside from that avoidable quirk, I encountered no operational failures or barriers to full functionality.
Compared to others
I also had on hand two lovely alternatives in the form of the Eastern Electric Minimax Supreme, and the iFi iDSD Micro. These are also 32 bit DACs featuring the ESS chip, so how could I not draw a comparison? Cutting to the chase, the Eastern Electric, featuring tube output, continues Alex Yeung’s affair with tube gear, and was the warmest, most bass heavy DAC. It softened the upper end and compensated with a rotund Bass presence.
Conversely, the iDSD, which was designed for portability, performed remarkably well, but could not carry the weight and fullness of the e22. The iDSD had to my ear the most absolute defined, detail-laden sound, but was soft on the bass, having not exceptional LF extension.
The exaSound Audio Design e22 chased away the shortcomings of these others and presented an exquisitely balanced performance both in terms of definition and tonality. Initially it did not seem as exciting to the ear as the iDSD, but with extended listening its lack of earnestness, it’s constancy without urgency, won me over. I felt no lack of information reaching my ears, but also was perfectly at ease, not fatigued in the least at listening to it for hours. With no perceptible skewing of the audio band my ears were content to listen to the entire spectrum without being drawn to one end of the spectrum, nor sensing a vacuum in the midrange.
With and without the TEO Audio Liquid Pre
While the exaSound Audio Design e22 was superlative against DACs, a premier preamp will boost the e22’s performance significantly. The name Liquid Pre alludes to its most exotic feature, metallic liquid conductors. This passive preamp was fortuitous in combination with the e22, such that I would loathe using the e22 without the TEO Liquid Pre. I have come to appreciate the sound of them together so much that I confidently recommend them both as a preamp/DAC solution.
I hasten to add that the exaSound Audio Design e22 may very well be a superior choice for output directly to your amp. If you are running an old 24/192 DAC of almost any pedigree, very possibly you may jettison your preamp and use the e22’s volume control for a superior experience. The e22 is fabulously quiet, brilliantly “fast” sounding, and not syrupy, nor harsh as though producing digital jitter. The TEO Audio Liquid Pre has a unique property in that it seems to match impedance with whatever component is used with it, such that it confers an advantage. Using the populist Cambridge Audio Azur 840E Preamp with the e22 was nice, but not emotionally stirring. However, there was no shortage of zeal when the Liquid Pre/e22 combo was introduced. The Liquid Pre extended the attributes of the exaSound DAC as if I had introduced $25K worth of amplification and cabling improvements.
Another way to consider this distinction between hearing the e22 alone versus with the Liquid Pre would be to consider a fine speaker company’s bookshelf versus floor standing products. Perhaps the smaller version uses the same midrange and tweeter drivers in a smaller enclosure, so the pedigree of sound would be consistent with the larger speaker’s character. However, there would be no denying the added ease and depth due to the larger cabinet of the floor stander, as well as due to the addition of a dedicated bass driver (or drivers). One is akin to a teaspoon of goodness, the other like a tablespoon of the same.
If the exaSound Audio Design e22 were tipped tonally up or down the frequency spectrum, as are the Eastern Electric or the iFi DACs, then I might hesitate to recommend it unreservedly as a replacement for a preamp. But, as it is wonderfully balanced, I think it would stand a fighting chance of being preferred to a goodly number of quality preamps.