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The Pinnacle of The Electrostatic Sound

Friday, December 30, 2016

Audiophile DAC Review!
Benchmark DAC3-HGC
D/A, Preamplifier, HP Amp

The DAC3 is firmly In The Better Hi-Res D/A Camp

Brevis...
Price: $2,195
Likes: super accurate conversion
Dislikes: doesn't look any different
Wow Factor: time to trade in your DAC2 
Info: Benchmark DAC3-HGC

by John Gatski
  The DAC2-HGC is the most-read review we have ever done on EAN, which is a testament to its audio quality and feature list, as one of the premium DACs on the market. Over time, however, new competitors came on the scene and have given Benchmark a run in their subjective audio performance.
  With the new Benchmark DAC3 Series, Benchmark is firmly back in the top tier of DACs — at any price. Equipped with the new ESS ES9028PRO 32-bit chip, the $2,195 DAC3-HGC, reviewed here, is the epitome of accuracy and neutral sonic character.
  The Benchmark DACs have always had fantastic specs, but this one has eked out even better S/N and flatter frequency response. The new chip’s THD compensation feature also helps project a cleaner bass and a more open, revealing soundstage that is as close to music as you can get. Gone is that “overwarmth” I often heard from the previous ESS Sabre-chip DACs. Via line out or headphone amp, you can hear the difference through the DAC3.
  Officially, the Benchmark web site lists the following DAC3 upgrades over the DAC2:
•Active 2nd Harmonic Compensation;
•Active 3rd Harmonic Compensation;
•Lower THD+N;
•Lower passband ripple;
•Improved frequency response;
•Faster PLL lock times;
•Faster switching between input signals.
  The last item on the upgrade list features a near instantaneous input source switching with out that little segment of phase-incoherent audio that typically occurs when switching between digital sources.

Features
  The Benchmark DAC3-HGC supports up to 24/192 PCM and 2.8MHz sampling DSD via  the DoP protocol. The new Benchmark DAC3 series is nearly the spitting image of the DAC2, which had its aesthetic design origins in the original DAC1 series of mid-2000s. The half rack, silver or black, with its series of status lights, headphone jacks and volume control. 
  Familiar Benchmark features include the sample rate and word-length indicators, which are based on specific LED arrays. Around back are two SPDIF coax digital inputs, two optical TOSlink inputs, a single USB 1/USB 2 input, two pairs of analog unbalanced inputs, two sets of analog unbalanced outputs and one set of balanced outputs.

New ESS chip brings a more-defined audio character to DAC3

  Included is a remote control, which switches inputs, controls the volume and enables bypass mode. The new DAC3 models, the DAC3-HGC and the line out-only DAC3-L ($1,995 with remote), both receive the upgraded signal path via the new ESS chip.
 The key to the Benchmark’s more-refined sound, especially in the air I hear around transient sounds, plus an even cleaner bass response is the new ESS chip and the same advanced employed Hybrid Gain Control (analog/digital) volume control that was employed in the DAC2. John Siau, Benchmark VP and chief product designer, said the DAC3 HGC’s “High-Headroom DSP” keeps the audio smooth — without affecting the accuracy of the signal in the DAC.

Taming the “overs”
  The DAC3 can handle signals as high as +3.5 dBFS, offering smoother-sounding performance on maxed digital recordings. According to Siau, most digital systems clip signals that exceed 0 dBFS. For years, he explained, the 0 dBFS digital audio limitation seemed reasonable, as 0 dBFS is the highest sinusoidal signal level that can be represented in a digital system. However, real-world measurements and math equations show that PCM digital systems can have inter-sample peaks that may reach levels slightly higher than +3 dBFS — though the individual samples never exceed 0 dBFS.

  Though audible improvements in DACs these days are mostly subtle, Benchmark delivers a new, audibly superior version over the DAC2, plus added a few ergonomic upgrades, such as faster source switching. It does not look any different, but it certainly sounds different.

  These inter-sample overs, however, create problems with the PCM interpolation filter, a key component of 24-bit DAC performance. Siau said the inter-sample overs cause distortion components that are audibly non-musical and harsh under subjective testing.   

Linear volume control is key
  To achieve linear volume control, the DAC3-HGC utilizes the same circuit, first implemented with the DAC2. It combines active analog gain control, passive low-impedance attenuators, a 32-bit digital gain control and a servo-driven volume control. All inputs are controlled by the rotary volume control, and the volume control moves in response to commands from the remote control.
  According to Benchmark, “analog inputs are never converted to digital, and digital inputs never pass through an analog potentiometer.” The digital inputs are controlled in 32-bit DSP, said to achieve optimal L/R balance, and precise stereo imaging, while avoiding any source of noise and distortion.


  Benchmark also believes its unique passive output attenuators are key to the DAC3's performance, providing distortion-free gain reduction — without reducing the dynamic range of the converter. The attenuators are said to optimize the gain staging between the DAC3-HGC and the power amplifier. This optimization is essential for maximizing the dynamic range of the entire playback system, Siau noted.
  Four balanced outputs are summed in balanced low-impedance I/V converters to form each of the two balanced output channels. National Semiconductor LME49860 op-amps (which can easily handle low impedance loads) are used throughout the audio path. An Alps motorized gain control is used to control the volume.

Sophisticated DSP
  As with the DAC2, the digital processing path consists of a Burr-Brown SRC4392 Digital Audio transceiver, and a Xilinx FPGA running custom Benchmark firmware. The DSP functions include Benchmark's UltraLock2(TM) jitter attenuation system, asynchronous upsampling, automatic de-emphasis, PCM and DSD filters, DoP decoding (for DSD playback), word-length detection and sample rate detection. The DAC3-HGC uses distributed voltage regulation. Each critical circuit has dedicated low-noise voltage regulators. The circuit board has six layers of copper and includes 3-dimensional shielding for critical signals.
  For jitter suppression, Benchmark relies on its UltraLock Jitter Attenuation and asynchronous USB2 input. According to Benchmark, the USB input uses an asynchronous USB transport mode to eliminate the computer and the USB connection as a source of jitter.

  When the Benchmark DAC2 first came out there were just a couple of DACs with word length (bit indicator) indication. Benchmark has since added the feature to all the Benchmark D/As. 

  The USB input operates either in a USB 2.0 mode that supports sample rates up to 192 kHz, or it can operate in a driverless USB Audio 1.1 mode — which supports sample rates up to 96 kHz. The USB input mode is switchable from the remote, or from the front panel. The USB 2.0 mode does not require driver installation on Apple Mac systems. A driver package is included to provide USB 2.0 support on Windows systems.
  As per the DAC2, the DAC3-HGC has a host of audiophile-focused functions: the SPDIF digital pass-through output, analog pass-through, sample rate and word length indicators and its DSD-over-PCM (DoP) compatibility — for playing DSD files.
  The DAC3‘s front panel contains two low-impedance, load-handling headphone jacks, audio mute/dim switch, polarity switch, power switch, and motorized volume control. An assortment of input indicators and the sample rate and word-length indicators complete the front section.
  When the Benchmark DAC2 first came out there were just a couple of DACs with word length (bit indicator) indication. Benchmark has since added the feature to all the Benchmark DACs. In my opinion, the bit status light or display on a DAC is key to show that bit-transparency is maintained from the audio player computer to the DAC.
  The DAC3‘s sample rate/word length indicator section contains 16-bit and 24-bit LEDs for word-length verification, and 44.1/48 kHz LEDs and 2X/4X LEDs for sample rate status. Thus, if your incoming signal is 24-bit/96 kHz sampling, the indicators show the 24-bit LED, the 48 kHz LED and the 2X LED (48 kHz x 2 equals 96 kHz). A 24-bit/192 kHz audio file lights the 24-bit LED, the 48 kHz LED and the 4X LED (48 kHz x 4 equals 192 kHz). DSD signals are indicated by simultaneous lighting of the 2X and 4X LEDs.


  The DAC’s back panel contains plenty of I/O. Ports include a two TOSlink and two coax inputs, one USB input, two sets of analog inputs, two sets of analog unbalanced outputs and one set of balanced XLR outputs. Digital input number four doubles as the digital pass-through (accomplished by moving an internal jumper). There is no analog balanced input or AES/EBU XLR digital input.
  The remote control duplicates all front panel functions including input switching, volume, dim/mute, and polarity controls. The classy remote is made of aluminum and has a nice feel; the buttons are easy to operate. The motorized volume control makes minimal noise as its servo operates. When you turn on the DAC3, the servo goes through its self-check and will move for a few seconds, before stopping at the last setting. When you push the mute/dim button from either the remote or front panel, it will lower the level. Hit it again  and it goes to the previous volume position.

The set up
  I deployed the DAC3-HGC into my audiophile system, which consisted of MartinLogan Montis speakers, Pass Labs X350.8 amp, and Benchmark’s ultra-quiet AHB2 bipolar output amplifier. I used the DAC3 as a preamp, and as a DAC through my Rogue Audio RP-5 tube preamp.
  Sources included an TASCAM DA-3000 hi-res player/recorder, Oppo BDP-105, an ASUS Android tablet with USB Audio Player Pro in the bit perfect mode, connected by USB 2.0; and a Macbook Pro laptop using Audirvana Plus.
  Other DACs on hand for comparison included the Mytek Digital Brooklyn, a Benchmark DAC2-DX, the recently reviewed Bryston BDA-3, and the older Mytek Stereo 192-DSD
  All analog, digital, and speaker cables were from the Wireworld Eclipse series. Power cords and power strip were courtesy of Essential Sound Products. For headphone listening, I used the AKG K702 Anniversary, the AKG K812, and the Oppo PM-1 and Shure SRH-1540.

The audition
  With all the gear set up, I popped in a USB stick full of hi-res music and played it through the TASCAM DA-3000, which was connected to the DAC3 via the SPDIF coax.
  First up, was a 24/192 dub of the Anthony WilsonOur Gang SACD. This 2001 DSD-direct Groove Note Recording, is a simple jazz trio (jazz guitar, drums and organ), which has a sparse, minimalist hi-res feel — featuring a warm Gibson guitar/tube amp tone, the girthy sound of classic Hammond B3 organ and close mic’d drums with great air around the cymbals.
  It takes accurate-sounding electronics to get this recording right. Components that are not clean on the bottom end make the recording sound midbass-heavy and the treble articulation gets lost — even with accurate speakers.
  As good as the old DAC2 sounded, over time I found that it sounded a little warm in the bass that translated to a slight fatness in the  midbass, depending on the recording’s bass presentation. Later, I found other ESS Sabre DAC chip-equipped D/As did the same. They exhibited a plump slowness in the more audible midbass. To my ears, it was a character of the 9018 chip. This warming was almost DSD-like.

The Anthony Wilson Trio title cut’s kick drum, and the midbass organ imprint was leaner, tighter and clearer. This allows the articulation of the air around the guitar notes and the cymbals to emerge to a proper balance.

  However, with this new ESS chip that low-end “over warmth” is gone. The Anthony Wilson Trio title cut’s kick drum, and the midbass organ imprint was leaner, tighter and clearer. This allows the articulation of the air around the guitar notes and the cymbals to emerge to a proper balance.
  I immediately noticed the improvement when A/B’ing the DAC3 and the DAC2. And it was confirmed by headphones, as well as line output through the preamp/amp path. I don’t know what ESS did in its new chip, or whether Benchmark tweaked the analog; or it is a combination of the two, but the emerging audio detail was more balanced than the DAC2.
  And that is really the essence of the sonic improvement of the DAC3; the precision and air inherent in good recordings is noticeably improved with the DAC3. All my reference Pop and Jazz ensemble, piano recordings, acoustic guitar and nylon classical guitar recordings sound more dimensional and alive. 


You know exactly what bit depth your music is with the DAC3

  I dubbed one of the Three Blind Mice classic albums that had been transferred to SACD, The Tsuyoshi Yamamoto Trio - Midnight Sugar. The 24/192 PCM dub includes the title track, which is an 11-minute slow burn to a faster tempo of stand up bass, a very percussive piano and drums.
  This 1974 analog tape, audiophile recording blends the right amount of space between the instruments with a potent piano velocity on the upper register notes. The DAC3 relayed a perfect blend of the instruments and serves up the piano note tinkle with plenty of attack, but no harshness.
  And the clickiness of the stand-up bass string plucks is gorgeous and airy, but not overpowering — a great balance of the low-end and the high-end. On the headphones, I could really hear the difference of this cut over older DACs like the Mytek Stereo 192 - DSD, which was harder edged and thinner sounding. Or the $900 Resonessence Concero, which also contains an older ESS chip.

Benchmark's best D/A
  I clearly heard audible difference when comparing the DAC2 and other older-generation D/As, additional A/B listening with more current DACs, with the levels carefully matched, the differences are harder to hear. Versus the stellar, do-it-all Mytek Brooklyn DAC (also an ESS chip), the results were very close, as was the case with the AKM-equipped Bryston BDA-3. The Brooklyn is about the same price; the Bryston is about $1,500 more. These are among the new-generation DACs that all give top-notch performance. For some audiophiles, the choices may come down to features and connections.

With the DAC3’s super fast PLL and switching relays, the DAC3 is pretty much an A/B switch. And the analog sources switch faster as well.

  By the way, one other area of improvement for the DAC3 is its switching speed from one digital source to another. When switching from say USB to SPDIF or TOSlink, most DACs have a few second ramp-up period where the newly-switched-in audio sounds phasey and inaccurate before the sound stabilizes. It was always hard to accurately discern real differences when A/B listening through the DACs because the new sources always sounded different than the previous source. With the DAC3’s super fast PLL and switching relays, the DAC3 is pretty much an A/B switch. And the analog sources switch faster as well.

CD player, computer or smart phone: they all work with DAC3

  Considering the audible bump in performance over the DAC2, the only real downside to the Benchmark is the fact it looks the same as the DAC2 (and DAC1). No upgraded look to the front panel. Also, the DAC3 does not offer the higher, native sample rates of PCM and DSD.  (up to 384/PCM and 4X DSD) that other DACs offer.
  I predict, however, that most audiophile listeners and existing Benchmark customers looking to upgrade their DACs will not care that 24/192 and 2.8MHz DSD are the max for the DAC3. After all, there are precious few PCM recordings beyond 192. And most computer programs will downsample the music to the DAC’s highest rate so it can be played. I played plenty of 2L 24/352 recordings through the DAC3 at 192 using Audirvana Plus. The quality was first rate.

The verdict
  As with the original DAC1 and DAC2, Benchmark proves it can take advantage of the latest DAC chip technology and notch up the performance of its latest version D/A, the DAC3.
  Though audible improvements in DACs these days are mostly subtle, Benchmark delivers a new, audibly superior version over the DAC2, plus added a few ergonomic upgrades, such as faster source switching. It does not look any different, but it certainly sounds different.
  Although it came out late in the year, the DAC3 was worth waiting for, and it receives the EAN Stellar Sound Award and a last-minute slide into the Everything Audio Network Product-of-The-Year Award in the DAC category.



  John Gatski has been evaluating consumer, audiophile, home cinema and professional audio gear since 1988. In 1995, he created Pro Audio Review, and he has written for Audio, LaserviewsEnjoy The MusicThe Audiophile Voice, High Performance ReviewRadio World and TV TechnologyEverything Audio Network is based in Kensington, Md. Articles on this site are the copyright of the ©Everything Audio Network. Any unauthorized use, via print or Internet, without written permission is prohibited. John Gatski can be reached via everything.audio@verizon.net






1 comment:

Anonymous said...

Hi John, I read your review of the Benchmark DAC3 with interest as I’m thinking about upgrading from my DAC1 HDR. So, first of all, thanks for posting such an informative and early review. It really helps potential buyers such as myself as it’s often hard (especially in the UK) to get a demo for Benchmark products.

I’m interested in one of the points you raised. You mentioned the old chip as being referred to as ‘warm’. I’m interested in this as a lot of the reviews of the DAC2 commented on the fact that the treble seemed a little more rounded off than in the DAC1. In your experience with all three iterations of the DAC would you say that the 3 is appreciably better than the 1 in that area? Mat