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This is the 40th in a series of reviews dedicated to the concept of 32Ohm Audio as embodied by the store of that name in downtown Portland/Oregon and described here - Ed.


Reviewer:
Srajan Ebaen
Financial Interests: click here
Source: Apple iMac 1TB with OSX 10.6.7, Pure Music 1.82 in hybrid memory play with pre-allocated RAM, AIFF files up to 24/192, Burson Audio HA160D as DAC, Esoteric/APL UX1/NWO-M; CEntrance DACmini [on review]
Preamps: Bent Audio Tap-X (AVC passive)
Amplifiers: FirstWatt S2 proto [on loan]
Loudspeakers: Aries Cerat Gladius [on loan]

Cables: Complete loom of Zu Audio Event, Entreq Challenger USB, Black Cat Cable Veloce and Stealth Audio Varidig S/PDIF
Stands: 2 x ASI HeartSong 3-tier, 2 x ASI HeartSong amp stand
Powerline conditioning: 1 x GigaWatt PF-1, 1 x Furutech RTP-6
Sundry accessories: Extensive use of Acoustic System Resonators, noise filters and phase inverters
Room size: 5m x 11.5m W x D, 2.6m ceiling with exposed wooden cross beams every 60cm, plaster over brick walls, suspended wood floor with Tatami-type throw rugs. The listening space opens into the second storey via a staircase and the kitchen/dining room are behind the main listening chair. The latter is thus positioned in the middle of this open floor plan without the usual nearby back wall.
Review Component Retail: $950


The ex DIYers of team Burson in Oz have pounded the drum on discrete voltage regulators and discrete opamps for years. In the digital domain, reinforcement for that notion now comes from none other than Daniel Weiss. Over the non-plus'd precursor, the I/V conversion and output stages for his new top Weiss Medea+ are fitted with his own OP1-BP discrete opamps [right].


Burson's HA-160D already gave us that technology for $1.150. So does the new $950 DA-160. Over the former it adds another 24/96 USB port* and one 24/192 Toslink for a total of four digital sockets; plus a paralleled second line-out. The three analog inputs and stepped precision resistor volume control of the headphone/preamp/DAC naturally go bye-bye. What does not is the classic BurrBrown PCM1793 24-bit chip fed from a constant current source with independently powered discrete Burson opamp during current-to-voltage conversion for high slew rate and fast recovery. But the DA-160 doesn't just see itself as a functionally stripped down HA-160D for smaller budgets. "We tweaked the power supply network into a constant current source power supply and we use two power transformers to lower the noise. The result is a more matured sound with even richer micro dynamics and substance."
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* The USB transceiver is a Tenor TE7022 as used in the €17.500 Soulution 540.

 
The DA-160 also gets a front-mounted hi/lo Z switch to trigger the variable output buffer into delivering the 2V output as either 25Ω/H or 45Ω/L. It's of course still a discrete class A output stage whose thermal dissipation is sinked into the massive 6mm aluminum vault-style enclosure. That gets mildly warm but far from hot. Having awarded the HA-160D and used it as my reference DAC over the Weiss DAC2 for its greater image density, tone colors and grippier more powerful bass, I've been bemused by occasional forum chatter dissing the Burson when discussing it in the company of machines by Grace, Wyred4Sound, Antelope Audio, Resonessence Labs et al.

With its low price, the HA-160D admittedly carries low street cred. On top of that, digital companies bang their drums on 64-bit proprietary jitter management, 32-bit converters, oven-controlled clocks and laboratory super measurements. Here Burson turns nearly taciturn. Having reviewed the DAC2 units by Wyred4Sound and Weiss, the Antelope Audio Zodiac Plus and Gold and Resonessence Lab Invicta, I know how digital buzz words versus superior analog design can diverge. Joël Chevassus who inherited my Yamamoto YDA-01 came to similar conclusions when tracking Vincent Brient's fully discrete TotalDAC development over multiple iterations (this machine eschews even converter chips in favor of precision resistors). Joël reported how changes in power supply and auxiliary analog circuitry made very noticeable improvements.
As ace digital designer Demian Martin put it, "today's converter chips no longer are the bottle neck". Their lab measurements already exceed what's audible in listening rooms. There low daytime background levels fluctuate around 40dB. Some chip specs already exceed the thermal noise floor of other parts necessary to make a functioning DAC. Never mind the operational noise floors of power amplifiers. It's thus the analogue stuff around the converter chips (power supply, I/V conversion and output stages) where real engineering still distinguishes itself. But that does rather make for less catchy copy.


Analog-centric Burson also focus on the high-value segment to not feed armchair sharks with their type of specmanship blood*. Burson thus doesn't register in adolescent dreams. There ESS battles the evil empire of Burr Brown whilst Crystal fights for universal dominion over AKM and Wolfson. In my little corner of this world none of it has yet rattled me to diss the HA-160D even though it functionally exceeds raw DAC needs.
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* Basic specs are an input impedance of 52KΩ, S/N ratio of >101dB, THD of <0.001% at 6mW/300Ω, channel separation of >95dB/10kHz, output impedance of 25/45Ω depending on selection and power dissipation of <25 watts from the internal regulated power supply. Dimensions are 180 x 250 x 80mm, weight is 5kg and the only available color is clear-anodized aluminum.

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