When Stan Beresford gave us the demo at The ASBO last Sunday of this tiny little box that he took out of his bag with a flourish, I didn't think any of us knew quite what to expect, if anything.  After all, we'd been listening to his rather good SEG DAC running from a 12V lead-acid battery and we knew that this was the best way to get great sound from it.  Better than a phone battery and way better than the small SMPS power supply available as an option.  Also better than a really good linear power supply like the Paul Hynes PR3.

Inside this box measuring all of 80 x 60 x 30mm is a filter/regulator and a goodly volume of supercap.  Supercaps use up to date technology and weird substances as dielectrics to pack a huge capacitance into a small package.  The result is a massive regulation effect and energy storage measurable almost in minutes rather than milliseconds.  They also respond very quickly to load demands and this, according to Stan, is the secret of their sound quality.  Powering the unit is a standard unregulated linear wallwart power supply.  It takes a couple of minutes to charge the box, during which time the LED turns slowly from red to blue, indicating full charge.

Since I could not use it without converting my SEG to 15V operation, I set about modding it after first listening to another box he gave me to try, this one taking the 12V battery input and driving a standard SEG.  What I heard was similar to the demo, so I'll jump straight to the 15V evaluation.

Showing the two Tokin 47kuF supercaps I've put in place of the original electrolytic capacitors (C87/C88).  There are two surface mount resistor changes required to preserve the headphone circuit when running at 15V.  I won't say how tricky this is as it's unprintable.  Suffice to say that you'll be better off having Stan upgrade yours rather than try it yourself.  For that reason, and on Stan's request, I'm not giving the details.



Knowing that this is a composite review, I decided to make some further changes while I was at it.  Firstly, I dropped a 20mm Hi-Fi Tuning fuse in place of the 2A DC fuse in the blue fuseholder.  Secondly, I decided to deploy two more Tokins in my small Chinese DC-DC converter, providing 5V to the Raspberry Pi.  I shall be doing some more work on the Pi at a later date when both USB outputs will be put to use.



Once done, I rebuilt the system and gave it a few minutes to settle while checking the voltages carefully.  I allowed the supercap PSU to fully charge to blue status before starting.  Here are the components laid out with damping/granite removed for clarity.  Batteries on the right supplying the DC-DC converter, displaying 4.98V into the Pi.  Stan's supercap PSU at the back, showing a blue LED indicating full charge, powering the SEG with 15V.



So how does it all sound?  Frankly, magnificent.  I could choose any music at all and describe the differences in presentation, clarity, dynamics and vividness.  Here are a few pieces I played, deliberately different from ones I've used in previous reviews.

Mindy Smith and Matthew Perryman-Jones sing well together and on Anymore of This I noticed how easy it was to follow either voice despite them apparently singing into the same microphone.  The sense of space around them and the sound of the studio was much more marked.  Brandi Carlile has a powerful voice and can soar mid-song into another level completely.  In The Joke she does just that, with an energy to the song that made me think I needed to turn it down, but instead sounding just exhilarating as she let rip.  Sweet Harmony by The Beloved has long been a favourite of mine and it sounded striking, with more focus to his voice and a fantastic sounding mandolin (?) solo after the second verse.  The sheer potency of Led Zeppelin's Good Times Bad Times sounded as good as I've ever heard it, right from the opening bars.  Norah Jones' Take It Back is an aural feast and her voice was amazingly breathy with some delicate guitar and keyboards accompanying her.  Finally, Larry Carlton's Room 335 was a superb rendition of a high energy band there in the room, acoustic completely portrayed, with great timing and interplay.

I did play one song I always play: Van Morrison's Satisfied, always a severe test of a system's ability to hold it together during high octane level changes while Van the Man is giving it all with his scratchy voice, not to mention the superb 'argument' between trumpet, flugelhorn and sax with pinpoint positioning.  Superb.

What this unassuming box has done is take the SEG, an already very good DAC, into a new level of performance.  It moves completely away from any idea of a hi-fi rendition towards a complete musical performance.  It demands that you keep listening because it makes the music so damned good.  You just want more.  In terms of sheer authority, it's now knocking on the door of my Ayre.  In terms of air, space, soundstage, reality, it vies with it depending on the song and is sometimes better.  I can't think of higher praise.

I'm well aware that I've made three changes at once, but the supercap PSU is giving most of the performance improvement based on what I heard at The ASBO and also based on listening to 12V for a while.  The Tokin 5.5V supercaps are great little devices, too, and well worth searching out for enhancing anything that runs from 5V.

Stan may have to prise this unit away from my dying hands...