Fourteen years ago when I started reviewing gear the digital analog convertor
(DAC) was a rare piece of gear. Few models existed and for most audiophiles,
fanatics, and hobbyists it was technology to watch rather than pursue.
Fourteen years later and DAC’s are an indispensable part of our hobby. The
quality and capability have risen dramatically, while the price/performance has
dropped even more so. The ability of DAC’s to pull out details in music that
would go otherwise hidden is what keeps us chasing the musical dragon.
This piece of equipment begins with the digital audio converter chip.
Manufacturers have a handful of different chips to choose from based upon
various goals. In the case of Tommy O'Brien's Digital Amplifier Company, the
chunk of silicon is the PCM1794A (one for each channel). If you know anything
about O’Brian, it’s that his electrical engineering background lasers his
focus to eliminating noise wherever possible. It starts with making sure the
signal path stays as short as possible. Output from each PCM chip is fed into
a Double Differential Output Filter. This design is right in line with his
amplifiers. Anyone who has spent time with one of his Cherry Amps knows how
true this is, as his amps are black ghost quiet.
Ironically enough, O'Brien's first DAC prototype came out sounding “tubey” by
his own admission even with 120db S/N ratio. Instead of dismissing the design,
he recognized that audiophiles do like the sound, and like any savvy business
person, he sells that model, the Dac Dac 1 TL. At the same time, knowing that
improvements can be had from further noise elimination via output circuits
three other models are available: The 1 HS, 2 HS (review model), and the 2 HSV
which has digital volume attenuation. The 2 HS can be used to drive amplifiers
directly as long as the source has a volume control.
For this review, O’Brian sent the DAC DAC 2 HS ($1290) along with the USB to
SPDIF coax converter box ($390). A few have dismissed the cases as DIY, but
the finish quality is too high as the metal edges are smooth, screws are
properly recessed, and the anodized red face is actually quite attractive,
though the artistic side of me misses the deep Ferrari red paint of his
Maraschino amps. While the Digital Amplifier Company is a small shop, the
packing is absolutely A+. Both pieces are shipped double boxed with several
inches of foam padding.
The main unit of the DAC DAC 2 HS is about as simple as it gets. The front
panel has just four horizontal green LED lights: Power, Valid Signal,
>50kHz, >100kHz. Once the cord from the external power supply is plugged
in, the 2 HS stays on. A nice touch is the Sorbothane feet for additional
isolation.
The back panel consists of a female power socket for an external power supply,
SPDIF, finally left and right XLR output jacks. To his credit, O’Brian does
supply quality Neutrik XLR to RCA converter plugs. The USB to SPDIF box does
not require a power supply, works with up to 384/32 signals, and is completely
isolated electronically. But it does mean that for most current digital music
users that one’s total investment rises to $1580. I would imagine at some
point in a version 2 design the USB input will be included in a single
box.
Listening Time
Since the DAC DAC 2 HS requires a preamp the review model was plugged into a
Parasound P6 (review upcoming) for the vast majority of the time. This also
allowed for comparison against the P6’s onboard Dac as well as my reference
Simaudio 230 HAD. Amplification was split between the Peachtree amp500 (class
D), Parasound A23 (solid-state), and a Vista Audio i34 (tube). Speaker
complement involved Magnepan .7’s, Totem Model 1, and Paradigm Prestige F75.
Source delivery is an iMac using both Tidal streaming and Amarra.
This summer Mark Knopfler has been in heavy rotation, therefore I started by
dialing up “The Man’s Too Strong” from Brothers In Arms. Just like O'Brien's
Maraschino Amplifier, the Dac Dac 2 HS noise level is ink black, thus allowing
for the maximum punch of the strumming power cords to be felt in equal balance
to the soft passages flanking either side of the string explosion. Another
critical impression that the 2 HS resolves is room effect on Knopfler’s
vocals. By shedding more noise the distinction of the recording space comes
into focus in balance with the slight nasal quality of the vocals. This is
especially noticeable in the title track, even with the long notes of the
electric organ.
Shifting to U2’s anthem “I Still Haven’t Found What I’m Looking For”, the
clean guitar notes open the track pop with intense color against the black
background. The ability to hear the various instrument layering in its most
musical beauty. Throughout the various tracks compared to the Parasound P6’s
respectable onboard unit was akin to the inside of a windshield before and
after cleaning. The difference is that blatantly obvious. The driving bass
line in the group’s “With Or Without You” can sound rather sloppy without a
decent Dac. The 2 HS reveals it to be a series of tight, controlled jabs.
Additionally, the late song tight quiet passage before the lead guitar solo
comes in is lean in time. It’s moments like that in music that make this
audiophile smile. Hearing each instrument’s unique sound while simultaneously
enjoying the blended melody is where it’s at for the listener.
Switching to acoustic works, Xuefei Yang’s Sketches of China reveals the
ability of the 2 HS to pull out nuances in percussion instruments, as well as
the tight plucks of top notes of the guitar. This is my favorite Tidal
discovery of 2020 and a great way to reveal the strengths and weaknesses of
equipment. The Spanish-inspired acoustic guitar songs easily define muddy vs.
clear reproduction. It also forces gear to prove whether it has warmth. In
this case, confirming there is no dryness in the 2 HS performance, tonal
naturalness is abundant, which begs the question of how much more of tubey
sweetness does the Dac Dac 1TL provides?
When it comes to poor digitized recordings due to loudness wars, no artist has
suffered more than Adele, though Billy Joel’s library from Columbia Records
suffers from the “crunch”. The underrated “Turning Tables” is a loudness war
victim. I’ve had the good fortune to hear what the incredible DCS Vivaldi does
to make the recording special, as well as the Benchmark Dac 3HDR. The 2 HS
130db signal to noise also makes the track listenable above 80db. Therefore,
don’t be afraid to enjoy marginal recordings with this dac, it’s going to
bring out the musicality.
Diving into Hi-Rez David Chesky recordings the 2 HS quickly recognized and
switched to the proper bit rate. The DAC DAC 2 supports all rates from 32kHz
to 192kHz, including 176kHz. However, the DAC DAC 1 TL and HS don’t support
the 176kHz sample rate. Since Chesky records at higher rates what one hears
are no sleight-of-hand, it’s the real deal. The 2 HS resolves the female opera
vocals and bassoon in “Sonnet No. 5” from his Espana recording with delicious
results.
Comparing the Dac 2 HS to the Simaudio 230HAD is limited to the sonic output
as the Simaudio is also a headphone amp, includes volume control, and has an
additional analog input. The 2 HS bests the 230HAD with a 15db improvement in
S/N ratio. Therefore the blacks are blacker, explaining the slightly softer
presentation by the Simaudio. I did not miss the 230HAD at all while reviewing
the 2 HS, though I’m not a fan of the green LED’s, silly as that sounds.
Final Thoughts
Being the son of a small business owner, I appreciate the value and intense
dedication that a small business brings to the market. Tommy O'Brien's
principle of following the rules of proven engineering and laws of electrical
engineering get under the skin of pure audio subjectivists, but there is no
argument that his products are well built, have a loyal following, and are
nearly impossible to find on the used market. The DAC DAC 2 HS may not be
flashy, but its performance is equal to any in its price range. Not only are
the basics done right, but just as important, every bit of sonic quality is
wrung out. Like all Digital Amplifier Company products, all DAC DAC’s are sold
Internet-direct, and demo 2 HS units are available for an in-home tryout. Give
Tommy O'Brien's DAC DAC 2 HS a spin, I’m betting you’ll be enamored like me!
Mark Marcantonio
Mark,
ReplyDeleteJust a note about the DAC DAC’s XLR-to-RCA adapters....
We make them custom because OTS types ground the negative side, causing distortion in DC coupled systems. We charge $90 for the custom ones we make using Neutrik “shells”, and they are purchased separately. I included them for you in case you needed RCA outputs.
Best Regards,
Tommy O’Brien
Founder
Digital Amp Co
CherryAmp.com
Sir, a small but niggling point - please stop writing 'DAC's' when you refer to more than one DAC - it's DACs, no apostrophe! You wouldn't write amplifier's as the plural of amplifier, or loudspeaker's instead of loudspeakers, would you? You're by no means the sole offender, but why it's becoming almost a norm is beyond me, it being so obviously incorrect (this isn't for publication, by the way - just a private, pretty please).
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