DAC1 PRE Stereo Preamp/DAC/Headphone Amp

The reference-quality Benchmark DAC1 PRE stereo preamplifier, headphone amp, and computer audio playback device (USB DAC), use the 24-bit, 192-kHz DAC1 digital-to-analog conversion (DAC) system. The DAC1 PRE is the culmination of years of high-precision analog and digital audio circuit design. Benchmark has achieved unprecedented sonic purity in their pro audio systems through an intelligent engineering philosophy”establish a pristine analog delivery path and eliminate digital distortion artifacts. The Benchmark DAC1 PRE continues this tradition of excellence.

With 6 stereo inputs and 4 stereo analog outputs, the DAC1 PRE anchors expansive media systems and provides a pristine audio path from source to amplifier. The 6 stereo inputs include an analog input, a USB computer input, an optical input, and 3 coaxial digital inputs. The output section includes stereo XLR balanced, RCA unbalanced, and 2 headphone jacks driven by Benchmark's HPA2 0-ohm headphone amplifier.

The acclaimed Benchmark DAC1 D-to-A conversion system
Engineers and audiophiles have grown to rely on Benchmark for critical digital audio conversion for more then 10 years. They are consistently finding themselves engaged in the music when using Benchmark digital analog converters”engaged in a way that is rarely achieved with digital converters.

The award-winning DAC1 PRE's superior performance has made it the 'Benchmark' of D-to-A converters. The DAC1 PRE gracefully merges the Benchmark DAC1 conversion system with elegant analog circuitry, Benchmark's HPA2 0-ohm headphone amplifier, and essential features and functions.

Jitter-Immune UltraLock Clock System

Benchmark's proprietary UltraLock clock system achieves an unprecedented immunity to jitter. Many modern (and expensive) converters suffer from significant jitter-induced distortion. If jitter is not effectively addressed, a converter will generate nonmusical sideband tones and digital distortion. Benchmark's highly regarded UltraLock clock system ensures that jitter is never a problem, even under extreme conditions. Even in the presence of extremely high input jitter, no jitter-induced artifacts can be detected on the outputs of the DAC1 PRE (using state-of-the-art testing equipment by Audio Precision). UltraLock will block more then 12.5 UI of jitter (@ 1 kHz). With the UltraLock clock system, the D/A conversion-clock in the DAC1 PRE is totally isolated from the clock of the digital audio source. The UltraLock clock system easily outperforms most well-designed two-stage PLL designs. The bottom line is this: Benchmark converters will consistently and faithfully deliver truthful audio without jitter-induced artifacts, no matter what variables are present.

AdvancedUSB Audio Technology

The USB interface of the DAC1 PRE operates with Benchmark's unique AdvancedUSB technology. Unlike many USB equipped D/A converters, Benchmark's AdvancedUSB technology supports 24-bit audio at sample rates up to 96 kHz without the installation of any drivers or other special software. Benchmark's UltraLock clock system isolates the converter from the high levels of jitter that are found on USB interfaces. AdvancedUSB responds automatically to sample-rate changes to bypass the operating system's sample-rate conversion. The DAC1 PRE achieves transparent, audiophile-quality playback through a true plug-and-play USB DAC.

It is very important to have a 24-bit USB path, even for 16-bit playback, because digital volume controls and other DSP function s can increase 16-bit audio to 24 bits. If a 16-bit USB DAC is used, up to 8 bits of each digital audio sample will be truncated resulting in significant, nonmusical digital distortion at audible levels.

Audio streamed via USB is subject to significant amounts of jitter. The AdvancedUSB interface utilizes the UltraLock clock system. Consequently, the performance of the USB input is equal to the performance of the other inputs, regardless of the jitter present. The DAC1 PRE is natively compatible with Windows 7/Vista/XP/2000 and Mac OS X. As a native device, there are no drivers or other software required to install or configure.

HPA2 Headphone Amplifier
The DAC1 PRE includes the HPA2 - Benchmark's signature high-current, 0-Ohm headphone amplifier. The HPA2 is arguably the ultimate reference headphone amplifier. It will deliver the full rated performance of the DAC1 to the headphones. The HPA2 maintains less than 0.0003% THD+N under a full load from two sets of headphones. The DAC1 PRE has two 1/4" headphone jacks on the front panel.

For mounting options, see RM Kit #485682, RM Coupler #485683, and RM Blank #485683.