Benchmark DAC2 DX - Digital to Analog Audio Converter - Discontinued

The DAC2 DX has been discontinued.

Overview

Benchmark Performance

The DAC2 DX is Benchmark's newest 2-channel D/A converter.  When compared to the legendary DAC1, the DAC2 has lower noise, lower distortion, and improved accuracy. The DAC1 became a reference standard in many of the finest recording studios and mastering rooms.  The DAC2 defines a new reference.

DAC2 converters deliver outstanding musical detail and precise stereo imaging.  They employ an advanced high-headroom digital filter design, and a new high-sample-rate Asynchronous USB Audio interface. All inputs are fully isolated from interface jitter by Benchmark's new UltraLock2™ jitter attenuation system.

Internal digital processing and conversion is 32-bits, and includes 3.5 dB of headroom above 0 dBFS. Three balanced 32-bit D/A converters are summed together to form the main output bus. Two channels are reserved for the auxiliary RCA output bus.

The performance of the DAC2 DX exceeds the measurement limits of today's state-of-the art test equipment.

Native DSD Conversion

DSD (in DoP 1.1 format) is automatically detected on USB, coaxial, and XLR digital inputs. The system seamlessly switches between native DSD and native PCM conversion. DoP 1.1 is supported by many media players, and DSD downloads are now available from several sources.

Enjoy seamless transitions between native DSD and native PCM playback.

Direct Connectivity to Power Amplifiers and Powered Monitors

Benchmark DAC1 and DAC2 converters are designed to directly drive power amplifiers and powered speakers.  Benchmark converters feature adjustable low-impedance passive attenuators at the XLR outputs that can be used to optimize the interface to the power amplifier (or powered monitor). The sonic importance of these attenuators cannot be overemphasized. Proper gain matching between the DAC/preamplifier and the power amplifier is essential for achieving peak system performance. The attenuators allow precise matching to all amplifiers and powered monitors.

Passive output attenuators are only found on Benchmark converters - don't settle for anything less.

Sonically Neutral

All Benchmark converters are designed for maximum transparency. This transparency is absolutely essential in the studio monitoring chain. DAC2 converters are ideal for critical reference-quality professional systems. In home applications, the DAC2 delivers the sonic signature that was created in the recording studio.

Hear the music exactly as it was heard in the studio.

Take the Studio Home

When Benchmark's professional converters are used in hi-fi applications, studio-quality sound can be enjoyed in a home environment.

Discover the natural, uncolored, analog sound of the DAC2.

The Digital-Only DAC2 for Audio Professionals

The DAC2 DX is the DAC2 of choice for users who do not need analog inputs.

The DX is well suited to the needs of professional users and includes an XLR AES digital input. The DAC2 DX is the only DAC2 model that includes dual stereo output buses. The analog output buses can be independently set to fixed or variable gain. The DAC2 DX is also the only DAC2 available in a rack-mount version.

A New Reference - Going Beyond the Legendary DAC1

Benchmark's DAC1 family of D/A converters have been the reference to which other converters have been compared. It is rare to find a converter review that does not draw comparisons to the DAC1. The DAC1 has been the best-selling 2-channel reference-quality converter and is in daily use at many of the finest recording studios and mastering rooms. DAC1 converters are also enjoyed by thousands of audiophiles. Benchmark has raised the bar ... the DAC2 defines a new reference.

The DAC2 DX replaces the DAC2 D

The DAC2 DX replaces the DAC2 D while adding several important features:

• Dual analog output buses
• XLR AES digital input
• 12V trigger I/O
• Improved DIM and MUTE functions

Professional Applications

• Reference-Quality Studio Monitoring
• Sound-Card Elimination for Computer Audio
• Stand-Alone Headphone Amplifier  for Digital Sources
• USB to SPDIF Transfer Device

Hi-Fi Applications

The DAC2 DX uses digital connections (USB, Optical, Coaxial, or AES) to bypass the low-quality built-in converters that are included in many audio products. 

• Audio Output Device for Music and Video Servers
• Home Hi-Fi Playback from Digital Sources
• Audio Output Device for TV and Home Theater Systems 

Add Benchmark Cables to Complete Your New System

Benchmark offers a no-nonsense selection of very high-quality cables. Benchmark cables are designed for durability and transparency, and most are manufactured in the USA. Our optical cables are manufactured in Canada.

Technology

Benchmark Technologies

Benchmark includes some exciting technologies in the DAC2:

• Hybrid Gain Control
• Low-Impedance Passive Output Attenuators
• High-Headroom DSP
• UltraLock2™ Jitter Attenuation System
• High-Headroom 32-bit DSP
• Quad 32-bit balanced D/A Conversion System
• Multi-Mode Asynchronous USB Audio System
• Digital Diagnostic Display
• Volume-Control Bypass
• Digital Pass Through
• Distributed Power Regulation
• "Zero-Ohm" HPA2™ Headphone Amplifier

Hybrid Gain Control

The DAC2 DX combines active analog gain control, passive low-impedance attenuators, a 32-bit digital gain control, and a servo-driven volume control. All analog outputs are controlled by the rotary volume control unless the volume-control bypass function is selected. This volume control moves in response to commands from the remote control. Audio does not pass through the volume control. The position of the rotary knob is precisely measured, and digital gain coefficients are calculated. The gain coefficients are filtered and passed to a 32-bit high-headroom DSP system. The 32-bit output of this system is connected directly to the array of 32-bit digital to analog converters. This system can provide a wide range of volume control without losing resolution. The DSP system preserves precise L/R balance, and precise stereo imaging, while avoiding any source of noise and distortion.

The volume control is one of the most critical functions in the audio chain, enjoy the best system available.

Low-Impedance Passive Output Attenuators

Benchmark's unique passive output attenuators provide distortion-free gain reduction without reducing the dynamic range (or SNR) of the converter. The attenuators optimize the gain staging between the DAC2 DX and the power amplifier. This optimization is absolutely essential for maximizing the dynamic range of the entire playback system. Much of the success of the DAC1 and DAC2 converters can be attributed to the passive output attenuators. Musical details can be obscured by system noise whenever a preamplifier and power amplifier are improperly matched. The passive attenuators enable full use of your power amplifier's dynamic range.

Experience new details in your favorite recordings.

UltraLock2™ Jitter Attenuation System

UltraLock2™ is an improved version of the UltraLock™ system used in the DAC1 and ADC1 product families. DSP processing is 32-bits, DSP headroom is 3.5 dB, sample rate is 211 kHz, and jitter-induced distortion and noise is at least 140 dB below the level of the music - well below the threshold of hearing.

Benchmark's UltraLock2™ system eliminates all audible jitter artifacts.

High-Headroom DSP

All D/A converters need 3.5 dB "excess" digital headroom, but few have any headroom above 0 dBFS.

All of the digital processing in the DAC2 DX is designed to handle signals as high as +3.5 dBFS. Most digital systems clip signals that exceed 0 dBFS. The 0 dBFS limitation seems reasonable, as 0 dBFS is the highest sinusoidal signal level that can be represented in a digital system. However, a detailed investigation of the mathematics of PCM digital systems will reveal that inter-sample peaks may reach levels slightly higher than +3 dBFS while individual samples never exceed 0 dBFS. These inter-sample overs are common in commercial releases, and are of no consequence in a PCM system until they reach an interpolation process. But, for a variety of reasons, virtually all audio D/A converters use an interpolation process. The interpolation process is absolutely necessary to achieve 24-bit state-of-the art conversion performance. Unfortunately, inter-sample overs cause clipping in most interpolators. This clipping produces distortion products that are non-harmonic and non-musical . We believe these broadband distortion products often add a harshness or false high-frequency sparkle to digital reproduction. The DAC2 DX avoids these problems by maintaining at least 3.5 dB of headroom in the entire conversion system.

We believe this added headroom is a groundbreaking improvement delivering significant sonic advantages.

Quad 32-bit Balanced Conversion System

Four balanced 32-bit D/A converters deliver audio to Benchmark's low-impedance current to voltage converters. The main bus feeds the balanced XLR outputs and one set of unbalanced RCA outputs. The main bus uses 3:1 redundancy to reduce conversion noise by 4.77 dB. The redundancy also tends to reduce distortion. A fourth set of conversion channels are reserved for the auxiliary bus that feeds the second set of RCA outputs.

Similar redundancy is built into the native DSD conversion system.

The analog circuits that follow the D/A converter are carefully designed. Benchmark has leveraged its long history of building high-end analog audio equipment, in order to create an outstanding analog output stage.

Digital converters are never better than the analog stages that support the conversion process.

Multi-Mode Asynchronous USB System

Benchmark's USB system supports USB Audio 2.0, DSD, and USB Audio 1.1. It is frequency agile, and will follow sample rate changes initiated by the computer and/or the media playback software. In all modes the USB communications are asynchronous in order to eliminate unnecessary sources of jitter.

The DAC2 DX has a low-jitter master clock which controls the transfer of audio data from the computer to the USB sub-system. The computer asynchronously transfers audio data to a buffer in the DAC2 DX. The contents of the buffer are then asynchronously transferred to the D/A conversion sub-system. This second asynchronous transfer eliminates any traces of jitter that accumulate as the data is transferred between the USB and conversion subsystems. No traces of jitter-induced distortion are measurable to our measurement limits (better than -150 dBFS). This truly represents the state-of-the art. Enjoy the convenience of computer playback without compromise. The Asynchronous USB system supports USB Audio 2.0 for high-resolution 192kHz, and DSD playback. No drivers are required for MAC operating systems. An easy-to-install driver adds 192 kHz and DSD capabilities to Windows operating systems.

An asynchronous, driverless USB Audio 1.1 mode supports sample rates up to 96 kHz. This USB mode can be selected from the front panel or from the remote control. The driverless USB Audio 1.1 mode allows quick plug-and-play connections to Windows, MAC, iOS, and many Linux operating systems without installing drivers. Just plug in the USB, and the DAC2 DX becomes an available audio device.

The USB subsystem remains active when the DAC2 DX is powered down. This prevents interruptions to the computer playback operations and eliminates the need to reconfigure the computer every time the converter is turned on.

Enjoy the convenience of USB connectivity without any compromise to audio performance.

Digital Diagnostic Display

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 and/or truncating to 16-bits. Many media players apply poor-quality sample rate conversion and truncation. Fortunately these problems can be eliminated with the selection of a good frequency-agile media player. The sample-rate and word-length displays on the DAC2 DX confirm the proper operation of your media player. These tools are also essential in the studio - get instant confirmation of sample rates and word lengths. The DAC2 measures the sample rate and examines bit activity, it does not use metadata flags (which are often incorrect).

Know when High-Resolution Audio is being delivered to your DAC.

Volume-Control Bypass

The DAC2 DX has two analog output busses. Each bus can be placed in a volume-control bypass mode in order to provide a full-level output to a downstream analog volume control. This is useful in many professional applications and is also useful when the DAC2 DX is feeding a Hi-Fi preamplifier.

The bypass function should be enabled whenever a Hi-Fi preamplifier is inserted between the DAC2 DX and the power amplifier. However, for best performance, Benchmark strongly recommends connecting the DAC2 directly to the power amplifier. The DAC2 DX performs all the functions of a DAC and a Hi-Fi preamplifier - a separate downstream Hi-Fi preamplifier can only degrade the performance.

The Volume-Control Bypass provides flexibility for specialized applications.

Digital Pass-Through Function

The second coaxial input 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 even supports DSD (DoP 1.1). Dolby digital and DTS formats can be passed through to a surround processor.

The Pass-Through Function provides a coaxial output for any USB-connected computer.

Power Switch

The DAC2 DX will enter a standby mode if the selected digital input is inactive for more than 5 minutes. Operation will resume when the selected digital input become active.The power switch places the DAC2 DX in "full shutdown". Power consumption is less than 0.5 W in "full shutdown". The DAC2 DX will respond the IR remote or the 12V trigger while in "full shutdown".

The DAC2 DX saves energy by meeting or exceeding all standby power standards.

Low Power Consumption

The DAC2 uses high-efficiency low noise power supplies and may be operated from any standard international voltage without adjustment. Low-noise audio circuits require generous amounts of power. High-efficiency circuits in the DAC2 deliver this power without wasted energy.

Power consumption is 12 W - typical.

Distributed Power Regulation

To achieve the lowest possible noise, the DAC2 D uses distributed power supply regulation. Each critical subsystem has at least one dedicated low-noise voltage regulator.

This power system is so effective that there no evidence of any AC line-related hum or noise at the output of the DAC2 - to a measurement limit of -160 dB FS.

"Zero-Ohm" HPA2™ Headphone Power Amplifier

The DAC2 features the HPA2™ - Benchmark's signature high-current, 0-Ohm headphone power amplifier. The HPA2™ is arguably the ultimate reference headphone power amplifier. It will deliver the full rated performance of the DAC2 to the headphones. The HPA2™ maintains less than 0.0003% THD+N under full load. The DAC2 has two 1/4" headphone jacks on the front panel. The performance of the HPA2™ remains consistent even when two headphones are being driven simultaneously.

The 0.11-Ohm output impedance of the HPA2™ maintains tight control of headphone transducers.

Awards

See more

Reviews

See more

Specifications

Audio Performance
Fs = 44.1 to 96 kHz, 20 to 20 kHz BW, 1 kHz test tone, 0 dBFS = +24 dBu (unless noted)
SNR – A-Weighted, 0 dBFS = +24 dBu	126 dB
SNR – Unweighted, 0 dBFS = +24 dBu	123 dB
THD+N, 1 kHz at 0 dBFS	-109 dBFS, -109 dB, 0.00035%
THD+N, 1 kHz at -1 dBFS	-110 dBFS, -109 dB, 0.00035%
THD+N, 1 kHz at –3 dBFS	-113 dBFS, -109 dB, 0.00035%
THD+N, 20 to 20 kHz test tone at –3 dBFS	-112 dBFS, -108 dB, 0.00040%
Frequency Response at Fs=96 kHz	+0 dB, -0.04 dB (20 to 20 kHz) -0.04 dB at 10 Hz -0.04 dB at 20 kHz -0.04 dB at 40 kHz -0.7 dB at 45 kHz
Frequency Response at Fs=48 kHz	+0 dB, -0.04 dB (20 to 20 kHz) -0.04 dB at 10 Hz -0.04 dB at 20 kHz
Crosstalk	-116 dB at 20 kHz -130 dB at 1 kHz -137 dB at 20 Hz
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	< -140 dB
Inter-channel Differential Phase (Stereo Pair – any sample rate)	+/- 0.25 degrees at 20 kHz
Inter-channel Differential Phase (Between DAC2 HGC Units Fs<110 kHz) Any sample rate.	+/- 0.25 degrees at 20 kHz
Maximum Lock Time after Fs change	400 ms
Soft Mute Ramp Up/Down Time	50 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)
Delay – Digital Input to Analog Output (function of sample rate)	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)	6 (1 USB, 2 Optical, 1 AES, 2 Coaxial)
Number of Channels	2
Input Sample Frequency Range	28 to 210 kHz (Coaxial and XLR) 28 to 96 kHz (Optical) 44.1, 48, 88.2, 96, 176.4, 192 kHz (USB)
Maximum Input Word Length	24 bits
Digital Input Impedance	75 Ohms Coaxial, 110 Ohms XLR
DC Blocking Capacitors on Digital Inputs	Yes (Coaxial and XLR Inputs)
Transient and Over-Voltage Protection on Digital Inputs	Yes (Coaxial and XLR Inputs)
Transformer Coupling on Digital Inputs	Yes (XLR Input)
Minimum Digital Input Level	250 mVpp (Coaxial and XLR 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
Jitter Attenuation Method	Benchmark UltraLock2™ - all inputs

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 Set Bypass Level (at 0 dBFS)	+24 dBu (Attenuator = 0 dB)
Output Level Range (at 0 dBFS) In ‘Variable’ Mode	Off to +24 dBu (Attenuator off) Off to +14 dBu (Attenuator = 10 dB) Off to +4 dBu (Attenuator = 20 dB)
Output Level Variation with Sample Rate (44.1 kHz vs. 96 kHz)	< +/- 0.006 dB

Unbalanced Analog Outputs
Number of Unbalanced Analog Outputs	4
Output Connector	RCA
Output Impedance	30 Ohms
Analog Output Clip Point	+13.5 dBu
Factory Set Home Theater Bypass Output Level (at 0 dBFS)	+8.2 dBu (2 Vrms)
Output Level Range (at 0 dBFS)	Off to +8.2 dBu
Output Level Variation with Sample Rate (44.1 kHz vs. 96 kHz)	< +/- 0.006 dB

HPA2TM Headphone Outputs
Number of Headphone Outputs	2
Output Connectors	¼” TRS with switch on left-hand jack
Output Impedance	< 0.11 Ohms
Output Level Control	Stereo Control on Front Panel
Output Level Range (at 0 dBFS) into 60-Ohm Load	Off to +17 dBu
Maximum Output Current	250 mA
Overload Protection (independent per channel)	Current limited at 300 mA, Thermal
Bandwidth	> 500 kHz
THD+N	-106 dB, 0.0005% into 30 Ohms at +18 dBu (1.26W)

Status Display
Indicators - Type and Location	16 LED’s on Front Panel
Selection/Status Indication	2 – Dim/Mute 6 – Input 2 – Bypass/Calibrated Output 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 15 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 47 – 63Hz

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
DAC2 only	3 lb.
DAC2 with remote control, power cord, extra fuses, and manual	4 lb.
Shipping weight	7 lb.

DAC2 DX Features

• Sample-Rate Display
• Word-Length Display
• Six Digital Inputs
• Three Stereo Analog Outputs
• Two Independent Analog Output Buses
• Digital Pass Through
• Dual HPA2™ Headphone Outputs
• Headphone Mute Switch - left headphone jack mutes main output, function may be defeated
• Native DSD Conversion
• Native PCM Conversion
• Asynchronous USB 2.0
• Asynchronous USB 1.1 for Driverless Operation
• Volume Control Bypass Function for Main Bus
• Volume Control Bypass Function for Auxiliary Bus
• 12V Trigger I/O - for sequenced system power switching
• Mute Relays - on all analog outputs
• Optional IR Remote Control - with heavy-duty metal housing
• Power Switch
• Low Power Consumption

Rack-Mount Options

The DAC2 DX is available in rackmount chassis. Non-rackmount versions can also be rackmounted using Benchmark's 1-RU tray.  All Benchmark DAC2, DAC1, ADC1, and MPA1 products are housed in a 1/2-wide 1 RU chassis.  Two units can be mounted side-by-side in a standard 19" rack. The rackmount version of the DAC2 DX is 1/2 rack wide and requires a blank plate and coupler if mounted by itself.

Manual

Detailed specifications and performance plots are available in the downloadable manual.

DAC2 DX Manual

Accessories

View a list of recommended accessories for your DAC2 DX here!

Downloads

Manual

Detailed specifications and performance plots are available in the downloadable manual.

DAC2 DX Manual

Driver

Windows operating systems require a driver when operating in USB 2.0 mode (required for 192 kHz operation).  No driver is required for Mac or Linux operating systems.  No driver is required for any operating system when operating in USB 1.1 mode (sample rates up to 96 kHz).

DAC2 Driver

DAC2 Application Notes

DAC2 App Notes

More DAC2 Reviews

DAC2 Reviews

DESIGNED, ASSEMBLED, AND TESTED IN THE USA

This Benchmark product was designed, assembled, and tested in the USA using USA and imported components. Most major components are made in USA.

Go to top of page →