The DAC1 PRE allows monitor switching of up to six sources in a variety of formats.
Whether you're mixing your latest 24-bit/192kHz opus, evaluating the project's reference CD or tweaking EQ settings for the release in MP3 format, having an accurate and flexible monitoring setup is indispensable. The Benchmark DAC1 PRE fills this need by switching effortlessly among six stereo inputs in various formats and providing a volume control for its reference-quality signal output.
That's a Switch
A detented rotary control on the table-top unit's face selects any of three coaxial digital inputs, optical (Toslink) or USB digital input, or analog input. (Connections for all are on the rear panel.) A status LED for each stereo input either lights steadily to indicate valid input signal or blinks to alert you otherwise. Another detented rotary control adjusts level at the unit's headphone and line-level outputs. (The latter are also on the rear panel.) Two ¼-inch headphone jacks sit side-by-side on the front panel. Plugging into the left one automatically mutes the unit's line-level outputs (this feature can be defeated), whereas signal from the right headphone jack can be monitored simultaneously with that for other outputs.
On the DAC1 PRE's rear panel, three coaxial digital inputs on RCA jacks and one optical (Toslink) connector can accept signals in either S/PDIF or AES/EBU format and at up to 24-bit/192kHz resolution. The “Type-B” USB connector accepts input (up to 24-bit/96kHz resolution) directly from a computer and is compatible with both Mac OS X and Windows Vista/XP/2000; no drivers need be installed. Both USB 1.1 and 2 are supported. Benchmark's UltraLock™ clock system purportedly eliminates jitter on all digital inputs, including USB. A pair of unbalanced RCA connectors accepts analog input from devices such as an iPod, analog mixer, FM tuner or tape deck.
Signals from the selected input source exit the DAC1 PRE via left- and right-channel balanced XLR and unbalanced RCA jacks (and the headphone jacks). The XLR and RCA output jacks are meant to connect directly with powered monitors or a power amp for passive monitors. The strength of the output signals exiting these jacks is determined by a three-way switch on the rear panel and internal trimmers and pads. (The pads affect XLR outputs only.) Depending on its setting, the switch either places the previously mentioned volume control in-circuit for XLR and RCA outputs (it's always active for the headphone outputs), sets fixed output levels determined by trimmer settings or mutes all but the headphone outputs. Pressing the input-selector rotary control also mutes the DAC1 PRE. An optional rackmount kit is available.
Might as Well Jump
Popping the unit's lid and repositioning internal jumpers to bypass the output pads, I used the DAC1 PRE successively as a D/A on my mix bus and on individual tracks (using one of the DAC1 PRE's coaxial inputs). The results were outstanding: The sound was always ultra-smooth and warm, exhibiting no glare or edginess.
Routing my digital mixer's S/PDIF output to one of the DAC1 PRE's co-ax inputs, the unit worked great as a level controller for my control room monitoring chain. Don't bypass the pads (set to -20 dB at the factory) or volume control when using the unit this way — fixed, unpadded output levels are extremely loud and could blow up your speakers!
Listening to MP3s on iTunes was plug-and-play easy. As soon as I connected a USB cable between my Mac QWERTY keyboard and the DAC1 PRE, “Benchmark 1.0” appeared as an output choice in my Mac's Sound Control panel. Connecting a fiber-optic cable between my CD player's optical output and the DAC1 PRE's optical input, CDs sounded great on playback. The DAC1 PRE's headphone outputs provided very loud levels and a nicely balanced sound.
For an all-in-one solution for quickly monitoring multiple high-res and low-res input sources in turn, the DAC1 PRE is hard to beat.
Mix contributing editor Michael Cooper is the owner of Michael Cooper Recording in Sisters, Ore. Visit him at