Reviewer: Marja & Henk
Financial interests: click here
Sources: PS Audio PWT; Dr. Feickert Blackbird MKII/DFA 1o5/Zu DL-103; Phasure XX-PC;
DAC: Phasure NOS1 DAC; PS Audio Direct Stream DAC [loaner]; DiDit DAC 212 [in for review]
Streaming sources: XXHighEnd; iTunes; Devialet AIR; La Rosita Beta; Qobuz Desktop
Preamp/integrated/power: Audio Note Meishu with WE 300B (or AVVT, JJ, KR Audio 300B output tubes); dual Devialet D-Premier; Hypex Ncore 1200 based monoblocks; Trafomatic Kaivalya; Trafomatic Reference One; Trafomatic Reference Phono One; Music First Passive Magnetic;
Speakers: Avantgarde Acoustic Duo Omega; Arcadian Audio Pnoe; Podium Sound One; Sounddeco Alpha F3; dual Zu Submission MKI; Soltanus Virtuoso ESL [in for review]
Cables: complete loom of ASI LiveLine cables; full loom of Crystal Cable cables; full loom of Nanotec Golden Strada; Audiomica Pearl Consequence interconnect; Audiomica Pebble Consequence; Audiocadabra Optimus Dual Headed USB cable [in for review]
Power line conditioning: PS Audio Powerplant Premier; PS Audio Humbuster III; IsoTek Evo 3 Syncro; AudioMica Allbit Consequence
Equipment racks: Solid Tech and ASI amplifier and TT shelf
Indispensable accessories: Furutech DeMag; ClearAudio Double Matrix; Franc Audio Ceramic Disc Classic; Shakti Stones; Akiko Audio sticks; Kemp polarity checker
Online Music purveyors: qobuz.com, bandcamp.com, amazon.co.uk  
Room treatment: Acoustic System International resonators, sugar cubes, diffusers
Room size: ca. 14.50 x 7.50m with a ceiling height of 3.50m, brick walls, wooden flooring upstairs, ca 7 x 5m with a ceiling height of 3.50m, brick walls and concrete floor downstairs.
Price of review item:  $89 for 1 meter, $109 for 1.5 meter and $129 for 2 meter

If USB weren’t such a no-brainer in use, it would have been abandoned for audio purposes long ago. In almost all other cases, one USB device talks to another in seconds, i.e. in just the time it takes to plug the connectors in. Most the time is actually spent finding the correct connector orientation. Once that connection is made and let’s say our computer running audio streaming software communicates with our USB DAC, the fun begins. When all is perfect, the resultant tunes are devoid of any drop-outs or crackles but full of dynamics. Transients kick in with impact and the soundstage has plenty of depth and all that is enjoyed at modest to low volume settings.


Yes, that would be nice and actually the case in an ideal world. Unfortunately, we don’t live in that ideal world (yet) and more often than not the perceived sound is noisy, lacks punch and dynamic contrast. A grey veil covers the musical landscape and with prolonged listening, neck pain and a headache are your reward. The cause? Mainly jitter. The signal your computer sends to the DAC is intended as nicely sharp-edged square waves as in the example below. Alas nature does not know square waves, only sine waves. To create that square wave upon which digital transmission relies, the computer must overlap several sine waves - or more precisely, several odd harmonics which are superimposed into a Fourier square wave.


That nicely composed square wave is now introduced to the USB cable that connects computer and DAC. The USB standard for the 2.0 version able to carry 480Mb of data per second states that the cable should comply with a 90Ω impedance. In addition, the data signal aka the proverbial 1s and 0s are determined by a 200mV positive difference between the D+ and D- signals for a 1; and a negative difference of 200mV between the D+ and D- signal for a 0. The standard USB cable has 4 leads, a power lead that carries 5V from the source to the connected equipment, two data leads—the aforementioned D+ and D—and signal ground.