• DAC3 Technologies

  • Harmonic Compensation

  • UltraLock3™ Jitter Attenuation System

  • High-Headroom DSP

  • Multi-Mode Asynchronous USB Audio System

  • Quad 32-bit Balanced D/A Conversion System

  • Distributed Power Regulation

  Harmonic Compensation

  The ES9028PRO features two distortion compensation systems that independently remove most of the 2nd and 3rd harmonic distortion in the D/A converter. Benchmark's ultra-clean analog output stages allow these systems to be fully utilized in the DAC3. To the best of our knowledge, no other D/A converter has lower THD than the Benchmark DAC3.

  UltraLock3™ Jitter Attenuation System

  UltraLock3™ is an enhanced version of the UltraLock2™ system used in the DAC2 product family. UltraLock3™ locks with precise phase accuracy in only 6 ms, compared to the 400 ms required by UltraLock2™. Both UltraLock™ systems provide virtually perfect jitter attenuation, but the lightning-fast lock time of the UltraLock3™ will be appreciated by many users.

  DSP processing is 32-bits, with DSP headroom of 3.5 dB, a sample rate of 211 kHz, and jitter-induced distortion and noise at least 140 dB below the music level—well below the threshold of hearing. Benchmark's UltraLock3™ system eliminates all audible jitter artifacts.

  High-Headroom DSP - with 3.5 dB "Excess" Digital Headroom

  All of the digital processing in the DAC3 is designed to handle signals as high as +3.5 dBFS. Most digital systems clip signals that exceed 0 dBFS, but a detailed investigation of PCM digital systems reveals that inter-sample peaks can exceed +3 dBFS, even though individual samples never exceed 0 dBFS. These inter-sample overs are common in commercial releases and are of no consequence in PCM systems unless they reach an interpolation process. Since virtually all audio D/A converters use interpolation, this can cause clipping, leading to non-harmonic distortion.

  The DAC3 avoids these problems by maintaining at least 3.5 dB of headroom across the entire conversion system, delivering a groundbreaking improvement in sound quality.

  Multi-Mode Asynchronous USB System

  Benchmark's USB system supports USB Audio 2.0 and DSD. It is frequency agile and follows sample rate changes initiated by the computer or media playback software. In all modes, USB communication is asynchronous to eliminate unnecessary jitter.

  The DAC3 has a low-jitter master clock that controls the transfer of audio data from the computer to the USB subsystem. The computer asynchronously transfers audio data to a buffer in the DAC3, and the data is then asynchronously transferred to the D/A conversion subsystem. This second asynchronous transfer eliminates jitter-induced distortion, measurable to better than -150 dBFS. This truly represents state-of-the-art technology, allowing the convenience of computer playback without compromise. The system supports USB Audio 2.0 for high-resolution 192kHz and DSD playback. No drivers are required for macOS, and an easy-to-install driver adds 192 kHz and DSD capabilities to Windows operating systems.

  The USB subsystem remains active when the DAC3 is powered down, preventing interruptions to computer playback and eliminating the need to reconfigure the computer every time the converter is turned on.

  Quad 32-bit Balanced Conversion System

  Four balanced 32-bit D/A converters deliver audio to Benchmark's low-impedance current-to-voltage converters. This 4:1 redundancy reduces noise and distortion to levels that set new benchmarks. The DAC3 conversion system is one of the best available. The analog circuits following the D/A converter are carefully designed, leveraging Benchmark's long history in high-end analog audio equipment to create an outstanding output stage.

  The 4:1 summing provides a 6 dB signal-to-noise improvement. The ES9028PRO is an 8-channel 32-bit converter, and in the DAC3, four channels are summed in the analog domain to form each of the two output channels. This summing also improves THD by averaging non-linearities across the four channels, reducing incoherent non-linearities by 6 dB.

  Diagnostic Tools - Sample-Rate and Word-Length Indicators

  Ever wonder why that 192 kHz 24-bit download on your computer just doesn't sound right? Your media player may be down-sampling to 44.1 kHz or truncating to 16-bits. Many computers and media players apply poor-quality sample rate conversion and truncation. Fortunately, these issues can be eliminated by selecting a high-quality, frequency-agile media player. The sample-rate and word-length displays on the DAC3 confirm the proper operation of your media player.

  Control Lock

  The DAC3 B can be locked to avoid accidental changes that could cause a loss of audio in dedicated applications. This feature disables the IR remote control and the front panel buttons.

  Digital Pass Through

  The second coaxial input on the DAC3 can be reconfigured as a digital output. In output mode, any selected digital input (including USB) will pass through to the coaxial output. The digital pass-through is bit-transparent and supports DSD (DoP 1.1). It also passes through Dolby Digital and DTS formats to a surround processor.

  Bi-Directional 12 Volt Trigger

  Benchmark re-invents the 12-volt trigger. The trigger connection on the DAC2 can be used as an input, an output, or both. It is compatible with any common 12-volt trigger input or output. The trigger can automatically turn a power amplifier on or off. The DAC3 will also respond to a 12-volt trigger to follow the actions of another audio component.

  Power Switch

  The power switch can place the DAC3 in standby or full shutdown. In full shutdown, the unit will still respond to the trigger input and IR remote control. Power consumption is less than 0.5 W in full shutdown.

  Low Power Consumption

  The DAC3 uses high-efficiency, low-noise power supplies and may be operated from any standard international voltage without adjustment. Power consumption is 12 W typical.

  Distributed Power Regulation

  To achieve the lowest possible noise, the DAC3 uses distributed power supply regulation. Each critical subsystem has at least one dedicated low-noise voltage regulator.

Audio Performance

• SNR – A-Weighted, 0 dBFS = +24 dBu
  125 dB, 128 dB relative to intersample peaks

• SNR – Unweighted, 0 dBFS = +24 dBu
  123 dB, 126 dB relative to intersample peaks

• THD+N, 1 kHz at 0 dBFS
  -113 dBFS, -113 dB, 0.00022%

• THD+N, 1 kHz at -1 dBFS
  -114 dBFS, -113 dB, 0.00022%

• THD+N, 1 kHz at -3 dBFS
  -119 dBFS, -116 dB, 0.00016%

• THD+N, 20 to 20 kHz test tone at -3 dBFS
  -113 dBFS, -110 dB, 0.00032%

• Frequency Response at Fs=192 kHz
  +0 dB, -0.015 dB (20 to 20 kHz)
  -0.015 dB at 10 Hz
  -0.005 dB at 20 kHz
  -0.031 dB at 40 kHz
  -0.15 dB at 80 kHz

• Frequency Response at Fs=48 kHz
  +0 dB, -0.015 dB (20 to 20 kHz)
  -0.015 dB at 10 Hz
  -0.005 dB at 20 kHz

• Crosstalk
  -137 dB at 20 Hz
  -130 dB at 1 kHz
  -116 dB at 20 kHz

• Maximum Amplitude of Jitter-Induced Sidebands (10 kHz 0 dBFS test tone, 12.75 UI sinusoidal jitter at 1 kHz)
  < -144 dB

• Maximum Amplitude of Spurious Tones with 0 dBFS test signal
  < -138 dB

• Maximum Amplitude of Idle Tones
  < -147 dB

• Maximum Amplitude of AC Line-Related Hum & Noise
  < -133 dB

• Inter-channel Differential Phase (Stereo Pair – any sample rate)
  +/- 0.25 degrees at 20 kHz

• Inter-channel Differential Phase (Between DAC3 Units Fs<110 kHz) Any sample rate
  +/- 0.25 degrees at 20 kHz

• Maximum Lock Time after Fs change
  6 ms

• Soft Mute Ramp Up/Down Time
  9.6 ms

• Mute on Receive Error
  Yes

• Mute on Lock Error
  Yes

• Mute on Idle Channel
  No

• 50/15 us De-Emphasis Enable
  Automatic in Consumer Mode

• De-Emphasis Method
  Digital IIR

• De-Emphasis Supported at
  Fs = 32, 44.1, 48 kHz

• Group Delay (Latency)
  1.36 ms at 44.1 kHz
  1.27 ms at 48 kHz
  0.90 ms at 88.2 kHz
  0.82 ms at 96 kHz
  0.51 ms at 176.4 kHz
  0.47 ms at 192 kHz

Digital Audio Inputs

• Number of Digital Inputs (switch selected)
  5 (1 USB, 2 Optical, 2 Coaxial)

• Number of Channels
  2

• Input Sample Frequency Range
  28 to 210 kHz (Coaxial Inputs)
  28 to 96 kHz (Optical Inputs)
  44.1, 48, 88.2, 96, 176.4, 192 kHz (USB Input)

• Maximum Input Word Length
  24 bits

• Digital Input Impedance
  75 Ohms (Coaxial Inputs)

• DC Blocking Capacitors on Digital Inputs
  Yes (Coaxial Inputs)

• Transient and Over-Voltage Protection on Digital Inputs
  Yes (Coaxial Inputs)

• Minimum Digital Input Level
  250 mVpp (Coaxial Inputs)

Jitter Tolerance (With no Measurable Change in Performance)

• 12.75 UI sine, 100 Hz to 3 kHz

• 1.5 UI sine at 20 kHz

• 1.5 UI sine at 40 kHz

• 1.5 UI sine at 80 kHz

• 1.5 UI sine at 90 kHz

• 0.25 UI sine above 160 kHz

Balanced Analog Outputs

• Number of Balanced Analog Outputs
  2

• Output Connector
  Gold-Pin Neutrik™ male XLR

• Output Impedance
  60 Ohms (Attenuator off)
  425 Ohms (Attenuator = 10 dB)
  135 Ohms (Attenuator = 20 dB)

• Analog Output Clip Point
  +30 dBu

• Factory Calibration (at 0 dBFS)
  +24 dBu (Attenuator off)

• Output Level Variation with Sample Rate (44.1 kHz vs. 96 kHz)
  < +/- 0.006 dB

Unbalanced Analog Outputs

• Number of Unbalanced Analog Outputs
  2

• Output Connector
  RCA

• Output Impedance
  30 Ohms

• Analog Output Clip Point
  +13.5 dBu (3.7 Vrms)

• Factory Calibration (at 0 dBFS)
  +8.2 dBu (2 Vrms)

• Output Level Variation with Sample Rate
  < +/- 0.006 dB

Status Display

• Indicators - Type and Location
  12 LED’s on Front Panel

• Selection/Status Indication
  1 – Control Lock
  5 – Input
  2 – Word length
  4 – Sample Rate

AC Power Requirements

• Nominal Input Operating Voltage Range (VAC RMS)
  100 – 240V

• Frequency
  50-60 Hz

• Power
  < 0.5 Watts Idle
  12 Watts Typical Program
  13 Watts Maximum

• Fuses
  5 x 20 mm (2 required)
  0.5 A 250 V Slo-Blo® Type

• Min/Max Operating range (VAC RMS)
  90 – 260 VAC
  47 – 63 Hz

Dimensions

• Form Factor
  ½ Rack Wide, 1 RU High

• Depth behind front panel
  8.5” (216 mm)

• Overall depth including connectors but without power cord
  9.33” (237 mm)

• Width
  9.5” (249 mm)

• Height
  1.725” (44.5 mm)

Weight

• DAC3 only
  3 lb.

• DAC3 with remote control, power cord, extra fuses, and manual
  4 lb.

• Shipping weight
  7 lb.

Important Features

• Sample Rate Display

• Word Length Display

• 5 Digital Inputs

• 2 Stereo Analog Outputs (1 RCA, 1 XLR)

• Digital Pass Through

• Native DSD Conversion

• Control-lock Switch

• Asynchronous USB 2.0

• Bi-Directional 12 Volt Trigger

• Power Switch

• Low Power Consumption

• ES9028PRO Converter