Hi folks,
This my first post but I've been reading here for a couple of months. I have a question as far as USB asynchronous dacs vs. what Audio Research's USB 2.0 HS has on their new dac8. Is one better than the other reducing jitter or is it just a different approach? Here are the spec's
Audio Research introduces DAC8 with complete high-resolution capability
May 21, 2010
We are pleased to introduce the new DAC8 digital to analog converter. Although physically similar to
its predecessor, the DAC8 represents new engineering that advances the state of the art in high
resolution USB audio.
Audio Research has maximized the USB capability of the DAC8 by incorporating USB 2.0 HS (High
Speed) which runs at 480Mbps. USB 2.0 HS has a lower jitter specification than USB 2.0 FS (Full
Speed 12mbps), consequently the DAC8 is capable of reproducing music at higher
definition/resolution (up to 24/192) than products communicating at USB 2.0 FS speeds (24/96).
In addition, the DAC8 employs a low jitter Dual Master Oscillator design that will provide superior
digital to analog conversion via its USB 2.0 HS input as well as via the more traditional S/PDIF (RCA,
BNC, Toslink and AES/EBU) inputs that are also included on the DAC8. Our USB 2.0 HS audio
interface is optimized for all six sample- rates currently in popular use; 44.1, 48, 88.2, 96, 176.4 and
192kHz.
In the past, S/PDIF was the default interface mode for High Resolution music files at 176.4 and
192kHz. Now, with Audio Research’s Dual Master Oscillator, USB 2.0 HS interface, and our Quad
D/A converter design, USB audio is finally elevated to the status once dominated by S/PDIF.
Consequently, regardless of whichever digital input you select, the Audio Research DAC8 promises
to provide a superior listening experience.
In addition to the High Performance USB design, the DAC8 features:
• “DAC8 HD Audio Device” software drivers, which allow listening to your music in its native
sample rate as well as assuring BIT PERFECT, low jitter, data transfer from the computer to
your DAC8. Because PC and Mac operating systems do not adequately support sample
rates over 96kHz, Audio Research has developed ASIO drivers to make the USB audio
experience sonically transparent at all sample rates.
• Sample Rate measuring function: Measures and displays the correct digital sample rate
being sent to the DAC8. This works in USB as well as S/PDIF mode. Consequently, at a
glance, you always know exactly which sample rate is being decoded.
• The DAC8 employs four 24-bit D/A converters. Each channel uses dual 24-bit D/A converters
running in mono mode to lower the noise floor and increase the dynamic range.
• Dual Master Oscillators: When the time base of any DAC is not an integer multiple of the
digital music sample rate, decoding and quantization errors occur. Consequently, the DAC8
uses two low jitter Master Oscillators; one for 44.1, 88.2 & 176.4kHz sample rates and the
other for 48, 96 & 192 kHz sample rates. The DAC8 automatically selects the correct Master
Oscillator the instant digital music is detected at the selected input.
• All inputs are galvanically isolated from the source to reduce or eliminate noise and/or jitter
from entering the DAC8.
• The Analog amplifiers in the DAC8 have received the same attention to detail as the digital
section. Each channel of the DAC8 uses a true direct-coupled differential amplifier with a
bandwidth in excess of 90kHz.
• The DAC8’s S/PDIF inputs are designed to accept signals from an HRx, 176.4kHz, 24-bit,
High-Resolution music server system playing HRx’s DVD-R recordings. See
www.referencerecordings.com/HRxSETUPS.asp for recommended music server setups.
• By virtue of all of the above points and our proprietary software drivers , intrinsic jitter has
been reduced to less than 10ps.
DAC8 HD AUDIO DEVICE SOFTWARE DRIVERS:
The DAC8’s USB driver software provides your computer with special high-speed audio drivers not
supplied by MS Windows or Mac OS. The Audio Research USB drivers are specially designed to
assure low jitter BIT PERFECT data transfer between the server/computer and the DAC8 at all
sample rates. Our drivers setup the USB interface to guarantee bandwidth, independent of active
bulk transfers from the hard drive.
From the ARC icon in your computer’s input tray you can set the DAC8 to any sample rate from 44.1
to 192kHz and allow the music server/management software to up or down convert your music to
the selected sample rate.
Audiophiles can use custom sample rate conversion algorithms or other file formats provided by
third party suppliers such as Windows Media Player, iTunes, J Rivers Media Center, Media Monkey,
FooBar, and many others to optimize your music experience.
The DAC8 is a fully balanced, zero-feedback, solid-state design utilizing a direct-coupled FET output
stage with generous regulated power supplies and seven stages of regulation. There are separate
new digital and audio power transformers, and the board material is the same as what we use in our
Reference products. Dynamic, forceful, immediate, and possessing remarkable resolution and
transparency, the DAC8 is a sonic knockout that is worthy of the finest music systems.
With a choice of high-resolution 24/192 S/PDIF inputs (RCA, BNC, AES/EBU and Toslink) in addition
to the highest resolution 24/192 USB available, the ability to adjust sample rates, the DAC8 provides
the new standard in high performance digital music playback.
Shipments will begin in June. The U.S. retail price is $4,995.00.
David E. Gordon
Managing Director, Sales
