Schede e recensioni

Aqvox USB2 MKII

Convertitore con entrata USB

Di cosa si tratta	Convertitore	L'importanza di iscrivervi alla newsletter
Produttore	Aqvox Germania
Caratteristiche	Entrata USB e Coassiale - 24 bit
Costo	1.000/00 € anno 2010

Caratteristiche

Descrizione

Dal web:

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.

Compatibility:
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 schalten lassen.)

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

USB Formatconverter
Converts from and to following formats : USB in/out maximum 48kHz/16bit
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

AES/EBU input:
16kHz, 32kHz, 44.1kHz, 48kHz, 88.2kHz, 96kHz, 176.4kHz, 192kHz at 16bit / 24bit

COAX input
16, 32, 44.1, 48, 88.2, 96, 176.4, 192 at 16bit / 24bit

TOSlink input
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 value.

NEW in the MKII Version:
Headphone amplifier in audiophile quality and USB headphone amp.
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 and 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 solution.

NEW in the MKII Version: LowNoise power supply, with 10dB quiter power output.
Our designers created a completely new LowNoise 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 and Mac , ASIO drivers are required.

Installation instructions: ASIO driver for USB, WinAmp, Foobar2000, etc..

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 ":

Fact list

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 jet stability and less than neglible noise.
USB-Codec: Texas-Instruments PCM2906 Transceiver. Digital Input Chip p Transceiver AKM AK4114 192khz 24bit

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 jet stability and less than neglible noise. Better sounding DA-chips. Dynamic 126db Signal to Noise 126db
Link : http://focus.ti.com/lit/ds/symlink/pcm1796.pdf

USB-Codec: Texas-Instruments PCM2906 Link: http://focus.ti.com/lit/ds/symlink/pcm2906.pdf
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. Link: http://www.asahi-kasei.co.jp/akm/en/product/ak4114/ak4114_f04e.pdf
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:
Link : http://www.asahi-kasei.co.jp/akm/en/product/ak4125/ak4125.html

All functions are controlled with a programmed ATMEL Microcomputer
Microcontroller: ATMEL MEGA48, 20MHz RISC, LowPower
http://www.atmel.com/dyn/resources/prod_documents/2545S.pdf

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: TOP-grade measurement-figures.
This technic/design is unique.

6. Passive analog filters
produces -because on principle- no dynamic distortions.

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 oscillator-modules.

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 or 24bit

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 like
CARA ( http://www.cara.de/ENU/index.html ) the analysis / optimizing of the room acoustics or speakers is possible.

14. A/D converter for USB with Microphone amplifier and 12-volt phantom power.

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 viewable pointers.

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
polypropylene capacitors.

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 mm

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)

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