USB DONE RIGHT: Two magic boxes that let computer audio ...

Listening Feedback Room
mean that any old wire will do. Yes, we
know, “bits is bits.” But then “tires is
tires,” right?
Coaxial digital cables are designed
to have a consistent internal impedance.
That’s important, because an impedance
mismatch can trigger a standing wave:
a signal “echo” that travels back and
forth down the length of the wire, and
can confuse the digital receiver circuit.
One way to minimize the standing
wave problem is to use a longer cable. A
1.5 metre cable is a good choice, because
the standing wave will take longer to
return. We’ve confirmed the difference
by listening.
We’ve been using an older Atlas cable
as a reference, the Opus. Originally
priced at $399, the Opus is now discontinued,
though our store still has stock at
$239. We selected two new Atlas digital
cables. both in the 1.5 m length. The test
cables were placed between our Stello U3
USB box (reviewed in this issue) and our
Moon 300D converter. Our three digital
selections were in 16/24 resolution,
played from our MacBook Pro computer.
The Ascent digital, 1.5 m, $250
We began with an old favorite, the
choral recording Now the Green Blade
Riseth. It sounds so good you might suppose
that it couldn’t possibly get spoiled,
but we know from experience that it is
surprisingly fragile.
The Ascent did quite well by it,
preserving the rhythm and the space.
The organ was present, though the flute
got somewhat lost after its opening solo.
Male voices were thinner, and the esses
were more prominent. Steve found the
sound too harsh for his taste.
We continued with Jen Chapin singing
Stevie Wonder’s You Haven’t Done
Nothin’. We are used to hearing it on
54 ULTRA HIGH FIDELITY Magazine
our Linn SACD player, but the CD layer
sounds superb too. On this recording the
Ascent sounded very much better, and
we agreed that it pretty well matched
the Opus. Chapin’s voice had excellent
articulation, and the space around her
was well rendered. The string bass had
lost some fullness, leaving more room for
the other accompanying instrument, the
saxophone.
We wound up that session with
Margie Gibson’s The Song is Ended from
her Say It With Music album. Once again
the Ascent was close to the Opus, giving
Margie the full measure of presence we
are used to hearing. The nuances that
make the performance so memorable
were all there. There was, to be sure,
a difference at the bottom end, which
seemed a little less solid. “It’s a little
muffled,” said Toby, “and it’s not quite
as warm either.”
The Ascent’s price is almost the same
as that of the now-discontinued Opus.
We prefer the Opus, but it’s discontinued,
and the stock won’t last forever.
The Mavros digital, 1.5 m, $625
What will paying more than double
the price buy you? This digital cable
has the same name as one of our analog
reference cables, and so we could hardly
wait to hear it.
Like the analog version, the Mavros
digital uses microporous PTFE foam as
an insulator. Both the actual wire and the
connectors are made from continuous
cast single-crystal copper.
We began with Now the Green Blade
Riseth, and in the first minute we knew
we had a winner.
One characteristic we look for in
a digital cable is coherence: the sonic
elements should hang together so that
they make sense, with no confusion. The
Mavros got it right. There was no smearing,
no exaggerated sibilance. “There’s
a huge sound stage filled with beautiful
music,” said Steve. This is as good as it
gets!
We were every bit as impressed with
the Jen Chapin song. This time the
sound was balanced and solid, with the
bass and the saxophone sharing the stage
equally. Both were wonderfully realistic,
with very good presence.
“But the flavor is different,” said
Toby. With the Opus the sound is lush,
but with the Mavros there’s an extra
measure of clarity. You can hear the lip
sounds, and just listen to the way Chapin
lets her voice trail off. This is a good
blend of science and sound.”
We were pretty sure the Mavros
would do well with the Margie Gibson
song, and of course we were right. From
the very opening, the bass and piano
were exceptionally plausible. Margie’s
voice was magnificent, with well-delineated
voice. Voice and instruments were
coherent and balanced. “I liked that,”
said Toby. “You can just listen and enjoy
what you want.” Steve wondered whether
the bass was thinner. “It’s possibly less
lush,” said Toby, “but that’s a matter of
taste.”
Some conclusions
As we’ve already noted, we had
decided to pick up the Hyper Symmetrical
and the Ascent Symmetrical for the
store. The Ascent digital might turn out
to be a good choice once the supply of
Opus digital cables was exhausted. The
Mavros digital was a go.
And indeed we purchased one ourselves
for our reference systems.
What about balanced cables?
We’ve already mentioned why we
don’t use them: we would be unable to
review non-balanced products without
also changing cables. However that’s not
a constraint you need to pay attention to,
and these cables are available in balanced
form, with XLR connectors, mostly at
considerably higher prices.
The Hyper Symmetrical balanced
has a list price of $753 (the coaxial
version is $413). The Ascent balanced
is $1182 (the unbalanced is $973). The
Mavros digital cable is available in AES/
EBU balanced versions for $670.