B.M.C. PureDAC Review

Operational features or what does this button do?

The separate volume and mute controls indicate that the preamp and headphone sections have discrete circuits dedicated to its own function.  This modular design approach should allow easy future upgrades for the user if the company has such plans.  The front panel is lit with an attractive white illumination which is not excessively bright or inappropriately dim.  In the circular center there is a display of the separate preamp and headphone volume levels, and bit sample rate indicator.  On the right side of the panel are terminal jacks for both single-ended (standard 1/4 inch jack) and balanced (XLR, 4 pin) headphone operation.  There is also a POWER button, and line source indicator display on the front.  I extended my giraffe-like neck and twisted my head – just as Alice in Wonderland did after eating the mushroom – to view the back panel connections.  And what connections they are!  All popular digital formats are provided by the inputs of the PureDAC: Toslink/optical (up to its 24-bit/96KHz limit), S/PDIF coaxial (up to its 24/96 limit), AES/EBU (up to its 24/96 limit), and both USB PCM (up to 32/384) and USB DSD (64 and 128).  For the USB mode, transfer of data from one’s computer is handled asynchronously by the unit’s master clock.  One set each of RCA (unbalanced) and XLR (balanced) outputs are provided for connection to a power amplifier or powered loudspeakers.  An ESS-Sabre chip is used for the main conversion, while a Wolfson chip is used for S/PDIF decoding.

The PureDAC is a substantial and fairly heavy unit (more than twelve pounds) for its type.  Also included is a power cord, remote control, owner’s manual and software CD.  For Microsoft based computers the CD contains a Window OS driver, which must be installed for proper USB operation.  The plastic remote control is small and replicates the front panel’s basic functions such as input selector, and separate line level and headphone buttons for volume and mute.  Since I’ve gotten lazier in the past year, I would prefer a power button added as well.

Setup, associated equipment, hardware/software, blah, blah, blah

Unless someone renders me unconscious and transports me to a different place, my 18 ½ x 14 ½ x 10 living room is where my main audio system resides and where I audition all equipment.  It is also the room where I watch the telly (TV to you yanks, wait I’m a yank too), stare into space and commit general dilly dallying.  I placed Redpoint Black Hole isolation feet underneath the PureDAC.  For this audition, both tube and solid state amplification provided power alternately, though the Music Reference tube amplifier did the vast bulk (approximately 90%) of the work.  I used my Rogue Audio 99 Super Magnum (tube) preamplifier most of the time, but I also used the line level preamp section of the PureDAC for a few days to get a sense of its sound or lack thereof.  The end result is that the two preamps sounded amazingly similar with the Rogue being a touch warmer in the mid-range region.

Loudspeaker duties were shared by ATM SCM active towers and a pair of KEF R300 bookshelf/stand mounts which I was reviewing concurrently – review forthcoming – with the PureDAC.  An OppO 981 DVD player served as a transport for spinning both red book and SACD, while a MacBook laptop loaded with Pure Music was also pressed into service for some high resolution files and USB use.  Headphone listening was provided by my Sony MDR-7506 professional monitors (standard 1/4 inch plug), a budget reference and favored by many studio/recording engineers.  I am not a big headphone user, so I don’t own any balanced units.  Unfortunately, I couldn’t think of anyone else either: friends, reviewer colleagues or audio club members who have balanced headphones.  Too bad since I really wanted to try this feature because B.M.C. touts the balanced output in their literature and website as a “reference level headphone” amplifier.