USB 2 D/A MKII - highend Digital to Analog
Converter / USB DAC
Manual USB 2 D/A MKII
- 05/2005 - review (in chinese) MKI
- 02/2006 - review (in german) MKI
- 03/2006 Nr. 310 - pro-audio review (in german) MKI
- 04/2006 #397- review (in greek) MKI
11/2006 - review test (in german)
- 01/2007 - Test (in german) Link
- 07/2008 - (suomi / finland) contest winner MKII
Introduction: fully balanced DAC - USB DAC -
HighEnd DA converteter - PC becomes audiopihile
The USB 2 D/A is one of the very rare true audiophile USB
DAC´s available with defeatable upsampling to 24/192
DAC - Digital to Analog Converter for use in high-end or pro
audio environment. Ideal for the new computer audiophile.
Supports up to 24bit / 192kHz sampling frequency via S/PDIF
COAX and AES/EBU, TOSLink and USB. Furthermore it is designed
to work as an external computer soundcard ( streaming device
) via USB 1.1 connection (no drivers needed for windows or
apple). (with optional USB2.0 Upgrade up to 192kHz/24bit inclusive ASIO)
With the integrated audiophile headphone amplifier all digital
inputs (even USB) can be monitored.
The USB2DA improves the audio signal of any CD/DVD Player,
PC, Notebook, DAW´s, Audio Streamer, Audio Server etc...all connectable
digital audio sources. And as streaming partner for Notebook
or Computer or MAC the -USB 2 DA- becomes a part of a true
audiophile hifi playback system.
The USB input/output is compatible with Windows98SE, Windows
2000, XP, Vista, Linux, Mac OS
black with silver inscription
Interior view (Click for magnified
view.) Rear view (Click for magnified
view.) 19" Rack Mounts
4 Digital inputs: AES/EBU, COAX, TOSLINK and USB (USB
bridges up to 10m). Für längere Strecken benötigt
man USB-Repeater bzw. USB Booster, die sich hintereinander
2 Analog outputs: balanced XLR and unbalanced RCA.
1 Digital output: COAX, TOS, AES/EBU-Input are routed
to the USB-output (up to 48kHz/16bit).
Audio file-formats: alle abspielbaren Formate:
lossless: ALC, AiFF, FLAC, FLA, WAV, PCM, WavPack,
SPDIF, via USB-Asio, Monkeys Audio, AIF, Audio-CD,
CDA, Apple Lossless
lossy file formats (lossy) MPC, MP+, MPP, MP1, MP2, MP3,
MP4 , LossyWAV, WMA, WMV, AU, OGG, AAC, MOV, AVI, AU, IFF, SVX, SND,
AAC, APE, MAC, VOC, mp3PRO
Converts from and to following formats : USB in/out maximum
USB to SPDIF - S/PDIF
SPDIF - S/PDIF to USB
COAX to USB
USB to COAX
TOSlink to USB
USB to TOSlink
AES/EBU to USB
USB to AES/EBU
USB to Analog symmetrical / balanced
USB to Analog unsymmetrical / unbalanced
Analog symmetrical / balanced to USB
Analog unsymmetrical / unbalanced to USB
PCM to USB
USB to PCM
digitalsymmetrical / digital balanced to USB
digital out to USB
Cinch to USB
USB to Cinch
sampling rate, sample rate, or sampling frequency in kHz
16kHz, 32kHz, 44.1kHz, 48kHz, 88.2kHz, 96kHz, 176.4kHz, 192kHz
at 16bit / 24bit
16, 32, 44.1, 48, 88.2, 96, 176.4, 192 at 16bit / 24bit
16, 32, 44.1, 48, 88.2, 96 ( sometimes up to 176.4 and 192kHz)
at 16bit / 24bit
USB - INput and OUTput
(with optional USB2.0 Upgrade up to 192kHz/24bit inclusive ASIO) 16, 32, 44.1, 48, at 16bit
No Op-Amps in signal path
The AQVOX USB 2 D/A was designed using innovative discrete
technology. Only single transistors are used in the amplification
stages. No integrated circuit amplifiers (OP-amps) and the
latest state of the art components to sound most dynamic,
highly detailed yet neutral and untiring. We believe the USB
2 D/A to be a unit with outstanding sound quality and an excellent
NEW in the MKII Version:
Headphone amplifier in audiophile quality and USB headphone
In the USB2DA-MKI version, only the USB-input was connected
to an average quality headphoneamplifier,
but in the new MKII version we connected ALL inputs (USB,
AES/EBU, COAX and TOSLINK)
to the new highend Headphone-Amp.
The fully discrete Class-A circuitry has no IC in signalpath
delivers exceptional soundquality.
A first class monitoring solution. The headphoneamp is coupled
directly to the DAC chip.
This saves the voltage gain stage - a shorter signalpath is
almost not possible.
No global overall feedback
Fully discrete (single transistors) Single Ended Class
A amplification technology and the use of just one amplifier
per balanced analog output stage provides you with today's
best possible sound quality. The amplifier section runs without
global overall negative feedback, only lokal FB is used. Thus
the amplifier generates drastically less dynamic distortions.
JitterEx precision-reclocking 192kHz/24Bit upsampling
Before the digital to analog conversion process, all signals
are upsampled and converted to 192kHz/24Bit (unless the bypass
is activated). This procedure is advantageous because DACs
can offer better performance at higher sampling rates. Upsampling
enables filtering to take place far beyond the range of human
hearing, as well as offering other, audible benefits, right
across the audio band, including improved transient response
and less ringing. This results in a more open, transparent
sound, tighter bass and a generally more "musical"
sound. Anyhow - AQVOX means it sounds better without Upsampling
- so set on BYPASS.
True balanced circuitry for entire analog signal path
Featured with an AES/EBU digital input and a balanced
XLR analog output the USB 2 D/A is the best choice for professional
users to monitor digital recordings. True balanced circuitry
for entire analog signal path. The USB 2 D/A is also excellent
for persons who strive for the highest level of sound quality
from their home audio systems, as well as for computer users
who like to get the best output quality from their Workstations
or Notebooks. No need to use a low-fi inbuilt soundcard. Furthermore
users can upgrade their micro hifi system (portable CD, MD...
as far as they provide a digital output) to a real high-end
NEW in the MKII Version:
LowNoise power supply, with 10dB
quiter power output.
Our designers created a completely new
powersupply. Now the power output delivers with 10dB lower
noise, cleaner energy and has a higher efficiency. Some better
prefilters where added to bann the dirt also in lower frequencys.
At the powersupplys output resides a linear regulator. The
result is audible. And the sound of the MKII is now better
even under bad power conditions.
To achieve best possible sound under
windows, ASIO drivers are required. For MAC we recommend eg PureMusic.
Installation instructions: ASIO driver for USB, WinAmp,
The most audiophile ASIO driver comes from AQVOX produces least jitter, is compatible with some other USB-DAC´s and plays with all Windows based mediaplayers/soundprograms. You can order this driver directly from us, just contact us here: contact form
The trialversion is free, here more info: http://www.aqvox.de/tech.html#matrix
Any PC´s, Computers, Notebooks with
an USB interface may be used as "audio-datasources ":
1. No Op Amp in signal path
2. No global overall feedback-loop, only very little local feedback
3. Dual Mono DAC (2 x Burr Brown PCM1796)
results in endless (optimal) channel-separation,
more dynamic current stability and less than neglible noise.
USB-Codec: Texas-Instruments PCM2906
Transceiver. Digital Input Chip p Transceiver AKM AK4114 192khz
Chips used inside the USB2DA : DA Converters
running in Dual Mono Mode. 2 x Burr Brown PCM1796 . The Dual-Mono Mode of
the PCM 1796 Stereo-DA-Chips results in optimum (endless) channel sparation,
improved dynamic current stability and less than neglible
noise. Better sounding DA-chips. Dynamic 126db Signal to Noise
Link : http://focus.ti.com/lit/ds/symlink/pcm1796.pdf
USB-Codec: Texas-Instruments PCM2906
Sends and receives the USB datastream, this Codec is only
engaged as an interface and makes it possible to use the USB2DA
as a Copystation.
The codec converts the USB-Datastream into
S/Pdif and hands them over to the Digital Transceiver
AKM AK4114 192khz 24bit 8 channel mux.
This device sends and receives S/Pdif and routes the S/Pdif
signal to the PCM1796 DAC chips.
If the upsampling function is enabled, the signal runs
through the Stereo Sample Rate Converter:
All functions are controlled with a programmed ATMEL Microcomputer
Microcontroller: ATMEL MEGA48, 20MHz RISC, LowPower
4. Current Amplification DAC to analog output-stage coupling.
reduced amplification-stages, and
driven in pure class-A operation.
5. Only passive elements are used in the filter-stages. Advantage:
This technic/design is unique.
6. Passive analog filters
produces -because on principle- no
7. Single ended Class A amplifiers
are known for musical and dynamic
sound. But require Class A layout.
8. Sample rate converted to 195kHz independent of input sampling.
independent of input frequency,
ultra stable 195kHz clock produces extremely low jitter signal.
9. Precision internal clocks for jitter elimination.
Temperature and ageing compensated
10. digital inputs: AES/EBU, RCA (16bit/32kHz - 24bit/192kHz),
Toslink (16bit/32kHz - 24bit/96kHz), USB 1.1 (6kHz - 16bit/48kHz) USB1.1 (USB2.0
compatible) Plug-n-Play no drivers needed (VISTA, XP, WIN2000,
WIN98, Linux and Mac OS X).
but for better soundquality we recommend to use an ASIO driver
11. sampling rate, sample rate, or sampling frequency in
kHz : 16, 32, 44.1, 48, 88.2, 96, 176.4, 192 at 16bit
12. Independent integrated PC USB 1.1 sound system functionality.
The USB 2 D/A can be used also like a external soundcard.
Via the USB-connection all digital
inputs and the analog Microphone input can be ein tentransfered
into the computer
Here information how to make digital recordings from the USB2DA
to a computer.
13. Digital data transfer from Microphone input to computer
via the USB port. With a measurement microphone and software
CARA ( http://www.cara.de/ENU/index.html
) the analysis / optimizing of the room acoustics or speakers
14. A/D converter for USB with Microphone amplifier and 12-volt
15. all digital inputs are routed to the USB output. (COAX
/ Toslink / AES/EBU to USB)
16. XLR and RCA outputs.
True balanced circuitry for
entire analog signal path.
17. fully discrete (no OPamp) headphone amplifier in Class-A
18. Sampling frequency indicator.
19. Digital de-emphasis.
20. Flat and dynamic roll off digital filter.
21. Selectable dither.
22. 3 selectable oversampling ratios.
23. 100V ...240V operating AC voltages.
24. Blue LED backlighted push-buttons.
25. Ultra clean switching power supply
with special pre- and
post filtering of AC power voltage.
26. Insensitive to AC voltage distortions, DC fragments,
noise and voltage stability.
27. Full aluminium casted turning knobs with long-distance
28. Full Aluminium extrusion casted and machined front panel
and side profiles.
29. All capacitors in signal path are finest inductive free-type
very low loss
30. Biological friendly lead-free CuAgSn silver solder.
31. PCB boards completely gold plated.
32. 1% metal-film resistors are used within the audio path.
33. 19" full-aluminium robust rack-mounts are available.
34. External dimensions (w / h / d): approx. 435 x 59 x 290
35. Weight approx. 2.8 kg
36. available colours: standard: complete black or complete
silver, optional extras: silver turningknobs and powerbutton
37. FUSE 250V 2A-T (lame)
*Product features, design, specifications, system requirements,
and availability are subject to change without notice.
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