Originally published at audiocircle.com by Ted_B « on: 6 Dec 2012, 05:43 pm »

First off, thanks to AC member, Mike Eastman, for letting me demo and eval this new DSD-capable DAC.

Part One: First impressions (day 1-3)
My first impressions of the Exasound E20 DAC come with a slight (or maybe large, we’ll see) caveat.  Although Exasound includes a 12V brick laptop style power supply in this $2499 DAC so far all listening was done using a 3rd party upgraded linear power supply, my Hynes SR3-12.  It seemed a natural fit as it is already set for 12V and uses the same dc plug that the E20 needs.   This “upgrade-ability” is a big plus for DAC designs like the E20.  Think about it:  you get to spend $$ on the DAC design only, use the stock (medical grade) ps for awhile, and then save up for upgraditis.  Plus, the EMI is a good 1 meter away, as no transformer is enclosed inhouse (reminds me of the saying "when criticizing someone first walk a mile in their shoes"...that way when you criticize them you are a mile away...and have their shoes!!  :) )

First off I want to say that these impressions are not meant to be a shoot-out among the DSD-capable DACs I own (Meitner and Mytek) and the E20.  I did very little a/bing with the Mytek so far, and none with the Meitner.  That being said, I’m well aware of the sound of each (and the price of each  :) ).  Now, on to Exasound and the E20.

Exasound is a relatively new small company in Toronto, Canada (wow, there are lots of good audio companies in Canada) headed up by George Klissarov.  I had a nice chat with George, and he seems to be the real deal.  He was unabashed about how and why I would remark about his DAC, and he felt that the world needed a more truthful, less hifi-sounding DAC; that is, more truthful for the lover of acoustical instruments where there is no perceived upper midbasss hump installed.  Maybe braver, in light of what other DACS try to do to poor recordings.   And George was very open to constructive criticism as he evolves the E20 design.  (Note:  I have a nice place in my heart for George cuz he and I are big multichannel music fans, too, and maybe I can help spur on a DSD-capable mch DAC, a kind of E18 with DSD.   :thumb:  ). 

So, first I’ll get out the constructive criticism.  The DAC uses a mini-USB connector (like a few of Antelope’s designs) and George is aware that this reduces the audiophile USB cable rolling habit to only a few, or requires a mini-to-standard adapter (which I used in my listening).  Second, the analog outputs on the back are reversed, with right channel outputs on the right (as you look at them from the back) forcing one to cross cables to their pre or amps.  Finally, the DAC is small and looks less $2500 than its competitors (kind of a “dollars per pound” criticism).  But the proof is in the sound, right?

The system used my CAPS v2+ Win 8 server, running J River in ASIO (Exasound’s own custom ASIO driver).  The E20 can be listened to in one of two ways; either directly to amps (George’s preference) using the supplied Apple remote wand (or any remote programmed in the E20 menu) or “bypassed” to a preamp (my addtl constructive criticism..I’d like a bypass function rather than setting the volume to max 0.0DB but maybe that is bypassed?). (Note: see George's comments at the end) The DAC is not overly hot, as 0.0db produces 2V RMS, perfect for my Concert Fidelity CF-080 preamp.  I listened in both setups.  In MY system, with my stuff, I much prefer going through the CF-080, as it produced a soundstage that was much more fleshed out, with better heft, weight, timbre, depth and width..losing no resolution.  But my pre is big $$ and I can imagine many folks preferring the dc-coupled output going “Apache” style into their amp(s).  The latter wasn’t bad, just not as good as my preamp.

OK, so what does this DAC sound like.  Well, again with my Hynes SR3-12 (which I stole from a AC seller for like $250) this DAC produced DSD that was easily the best I’ve heard under $3k, and redbook PCM that rivals my $7k Meitner.  This is not to say that the 24 bit rates are trash, no, simply that the redbook playback was what drew me in to thinking this DAC is really something special.  Again, these are first impressions, and I will spend more time in 24 bit land going forward.  I need to dust off my 352K DXD stuff, too.

The E20 has an ease and musical PRAT that just does not produce listener fatigue at all, over several hours.  It has no real downsides in PCM, it’s only downside in DSD being that it does not render the musicality of my almost-3X as expensive Meitner like it seems to do in PCM.  DSD was good, as good as I’ve heard in this price range, but tended to not have the millions of colors, nor the perfect control during complexity that the Meitner does.  Bass control, bass tunefulness, frequency extremes, midrange glow (but not bloom) and soundstage rock solid-ness!  All there, with redbook especially.  It has no issues with drivers or sample rate changes, and seemed to have fire up from a power reboot easily, after the requisite server reboot (most DACS like to be the first one on when a server is rebooted, so the server can recognize the powered DAC immediately).

As I’ve said multiple times now, this was a first impression, and was using a very nice linear power supply.  But if you have Bath Ruth on the bench, why not use him.  J  I will, over the next few days, listen intently to the stock ps as well, and will report back on any changes.  Until then, we have a new $2500 DAC to put on the recommend list!!

Ted

Editor addendum:
George Klissarov's clarifications of two issues: volume bypass and operator error safeguards

1) Let me explain about the volume control – it is not analogue nor digital… it is right in-between the two worlds. The signal over the USB  from the computer to the DAC travels always at the 0 dB level. So there is no bit-loss like in digital volume controls.  When you request a volume level, we send a command to the DAC – a couple of bytes to instruct the DAC chip ES9018 to produce lower voltage. So the 0dB sound stream is converted to lower voltage analogue signal. 

From the analogue side of the equation,  the signal is not attenuated, it is just born smaller. So you don’t have the signal to noise difficulties of conventional analogue volume controls.

Back to the bypass of volume – you have it. If you see 0dB on the LCD display, it is our guarantee that the command sent to the DAC chip is “don’t mess with the volume”.  The purpose of the display is honesty. Drivers can mislead you about sampling rate or volume level. When we put it in the display it is “carved in hardware”. It is a commitment.  By the way the display blinks if the asynchronous buffer gets empty – another clear indication of trouble free streaming.

2) we also have a safety net around power up and shut down. Look at the blue note  icon on the tray. It takes a second to recognize that the USB is connected and to display the red square. This is self test time. There are 4 sates
•   Cable disconnected – exclamation mark over the blue note
•   Blue note – cable connected but unit is off
•   The unit is connected and ON  - red square over the blue note
•   Green triangle over the blue note – the unit is playing.

If you accidentally unplugging the USB or power cables, there will be no bangs.  There is enough power stored inside the unit to keep the controller alive after loss of power, so that the relays will quietly cut off the outputs.  Don’t try this without a preamp with lowered volume first – there are factors beyond the DAC – for example static charges on your hand. On Mac we can continue playback after you reconnect the USB.

Part Two: Final Impressions (24/352 and stock power supply)

Re: DAC review: Exasound E20 32/384k DSD DAC mini-reveiw 

Originally published at audiocircle.com by Ted_B « on: 7 Dec 2012, 06:48 pm »

Well, I swapped out my Hynes SR3-12 (12V linear power supply by Paul Hynes) and instead installed the stock SMPS medical grade power supply (looks like a laptop-style brick) that is included with the DAC.   I was expecting a significant downturn in sonics.  What i got wasn't insignificant, but wasn't a deal breaker either by any means.  The soundstage depth narrowed ever so slightly, the weight of the lower midrange and deepest bass got slightly lighter, and the air that is 12k-ish lost a little. Not a huge big deal, frankly.  If I had started with this power supply I would have said all the same things about this DACs ability to do PCM, especially redbook.  It is a very musical DAC that creates a wonderfully timbre-rich soundstage, yet delivers the micro-details so evident in modern DAC designs (so many ultra-detailed DACS, though, have no sense of timbre, color or PRAT).  If I had started with this power supply I would have said all the same things about its ability to do DSD, both DSD64 and DSD128.  The E20 conveys my favorite aspects of DSD, a smooth yet quick attack and leading edge (yes, the edges are fast but smooth on DSD), a musical but tight bass register, and a grain-free sense of space....all there.  With the Hynes it is slightly closer to my Meitner reference, but again, that is an upgrade option not available on DACS with internal power supplies.

I don't have a lot of DXD (aka 24/352k PCM) but what I have is well-recorded 2L light classical, almost folk classical at times.   The E20 renders 352k with the same sense of PRAT that it does to redbook and 24/176k, but with even more (of course) resolution and what I call "palettte of colors", i.e timbre/tone.  Note:  it might simply be a weird coincidence but I like everything based on 44k on this machine slightly better than anything based on 48k.  It's not that 24/96 or 24/192 doesn't sound very good; it does.  But the giant-killer sound comes from 16/44 and 24/176k.  Maybe just me.  :)

As stated earlier, George Klissarov and his Company seem quite open to feedback, and have a trial/demo period stated on their website that should allow most AC members, especially N. American-based, to evaluate this DAC in the only place worth evaluating from...your own system in your own uniquely sounding room.  Have fun.