Overview; Dac1 And Dac1 Usb Heritage; Applications; Advancedusb Audio™ Technology - Benchmark DAC1 PRE Instruction Manual

Overview

The DAC1 PRE is a reference-quality, 2-
channel 192-kHz 24-bit digital-to-analog
audio converter, stereo preamplifier, and
headphone amplifier. It features
Benchmark's AdvancedUSB Audio™
technology, UltraLock™ clock system, and
HPA2™ headphone amplifier.

DAC1 and DAC1 USB Heritage

The pristine audio path of the award-winning
DAC1 has made it the 'Benchmark' of stand-
alone D/A converters. The DAC1 USB and
DAC1 PRE preserve the exact topology of the
DAC1 audio path while adding some of the
most frequently requested features.
With the introduction of the DAC1 USB we
added a very unique USB input with native
96/24 capability, an auto-mute function for
headphone use, customizable headphone gain
range, an automatic standby feature, and a
high-current LM4562/LME49860 output stage
designed to drive long cables and/or difficult
loads, such as high-end power-amplifiers.
The DAC1 PRE adds the versatility of a
stereo analog input and three S/PDIF digital
inputs. National LM4562/LME49860 opamps
are used throughout, and all RCA connectors
are premium bulkhead mounted RCA
connectors for maximum durability and
superior grounding.
The DAC1 PRE looks, sounds, and measures
the same as the DAC1 and DAC1 USB. We
have added convenience and flexibility
without altering the performance or changing
the signal path.

Applications

The DAC1 PRE is designed for maximum
transparency and is well suited for critical
playback in studio control rooms, mastering
rooms, and high-end audiophile applications.
DAC1 PRE Instruction Manual Rev J
Benchmark's AdvancedUSB Audio™
interface makes the DAC1 PRE an ideal
primary output device for digital audio
workstations, desktop audio editing
applications, computer-based media
playback, home media servers, and
computer-based radio broadcast systems.
A rugged rack-mount adapter makes the
DAC1 PRE an excellent choice for location
recording, broadcast facilities, and mobile
trucks.
AdvancedUSB Audio™ Technology
The USB input is compatible with Windows
Vista/XP/2000 and Mac OS X with no driver
installation or system configuration required
(see www.benchmarkmedia.com/wiki
to-date compatibility information).
Benchmark's AdvancedUSB Audio™
technology supports sample rates up to 96
kHz and word lengths up to 24 bits.
The DAC1 PRE is a true plug-and-play
solution, and it will be ready for playback
immediately after the unit is connected to a
USB port for the first time.

Jitter-Immune UltraLock™

The Benchmark UltraLock™ system is nearly
100% jitter-immune. The D/A conversion
clock is isolated from the input digital audio
clock in a topology that outperforms two-
stage PLL designs. In fact, no jitter-induced
artifacts can be detected using an Audio
Precision System 2 Cascade test set.
Measurement limits include detection of
artifacts as low as -140 dBFS, application of
jitter amplitudes as high as 12.75 unit
intervals (UI) and application of jitter over a
frequency range of 2 Hz to 200 kHz.
Any signal that can be decoded by the USB or
AES/EBU receivers will be reproduced without
for up-
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