The Well-Tempered Computer

Abbingdon Music Research - Digital Processor-777 €3.600

24/192kHz Asynchronous USB Audio Class 2.0 (XMOS)

Thermionic Electron Valves amplification stage:	2 x 6H1n-EV / 1 x 6H11P fitted ECC88, E88CC, 7308, Cca, 6DJ8, 6922, 6H23n-EV optional
Total Harmonic Dist. + Noise (THD+N):	<0.3%
Dynamic range:	>90 dB
Digital Audio Inputs:	2 x XLR/BNC with HD Valve Digital Input technology 2 x RCA/Toslink SPDIF Interface 1 x 24/192 Asynchronous USB

Audiolab M-DAC+ €999.99

DAC	ESS Sabre32 9018 chip
Sampling Rate	24-bit / 192kHz (Optical, Coaxial, AES) 32-bit / 384kHz (USB) 2.8MHz (DSD64), 5.6MHz (DSD128), 11.2MHz (DSD256)
Digital Input	2 x Coaxial, 2 x Toslink Optical, 1 x AES/EBU, 1 x USB for PC USB, 1x USB for iPod/iPhone/iPad
Digital Output	1x Coaxial, 1 x Toslink Optical
Output Voltage	Balanced: 4.5V RMS Unbalanced: 2.25V RMS
Output Impedance	Balanced: 20Ω Unbalanced: 10Ω
THD (1kHz 0dB 20Hz - 20kHz A wtd)	<0.002%
Frequency Response	20Hz - 20KHz (± 0.2dB)
Signal to Noise Ratio	RCA: > -115dB, XLR: > -120dB
Dynamic Range	RCA: > 115dB, XLR: > 120dB
Crosstalk	RCA: > 120dB, XLR: > 130dB
Dimensions (mm)	114mm x 247mm x 292mm
Net Weight	3.7kg

Added 2019

aqua acoustic quality La Scala MKII D/A Converter €4890

R2R ladder DAC with 4 Burr-Brown PCM -1704K arrayed in a true differential dual mono configuration.

ECC81 tube

THD + N <0.1% 1KHz -20dB

• Input:
- etherCON RJ45 AQlink (I2S serial bus) - 24 bit / 384 KHz
- AES/EBU balanced 110 ohm - 24 bit / 192 KHz
- BNC coax (S/PDIF) 75 ohm - 24 bit / 192 KHz
- RCA coax (S/PDIF) 75 ohm - 24 bit / 192 KHz
- USB port - 24 bit / 192 KHz
- AT&T (ST Fiber) - 24 bit / 192 KHz (optional)

• Analog output:
- RCA single-ended
- XLR balanced symmetrical

Added 2014

Asus Xonar Essence One € 400,-

Chipset	Audio Processor :C-Media CM6631 High-Definition Sound Processor
Sample Rate and Resolution	44.1K/48K/88.2K/96K/176.4K/192KHz @ 16bit/24bit S/PDIF Digital Input : 44.1K/48K/96K/192KHz @ 16bit/24bit ASIO 2.2 Driver Support :
I/O Ports	Analog Output Jack : 2 x 3.5mm RCA jack 1 x 6.3mm RCA jack 2 x Balanced Output (XLR) 2 x Digital S/PDIF Input : 1 x Coaxial, 1 x Toslink 1 x USB Input

ATOLL DAC200 €1500

Pre-amp with various digital inputs and headphone out

Inputs

1 AES/EBU
2 SPDIF coaxi
3 SPDIF optical
1 USB : 24bits/192kHz (XMOS, driver for Win)
1 wireless dongle

Outputs:

1 coax
1 optical
1 RCA
1 XLR
1 headphone

DAC: BURR BROWN PCM1792 (24 bits/192 kHz)

Audeze DECKARD $699

Line Out
Type	Single-Ended Class-A
SNR	106dB A-Weighted
THD+N	0.00045% at 1kHz 2VRMS A-Weighted
Frequency Response	5Hz-100kHz, -1dB (-0.03dB at 20Hz/-0.07dB at 20kHz)
Line Out Impedance	50 ohms

Headphone Out
SNR	106dB A-Weighted
THD+N	>0.1%, 20Hz - 20kHz 4W with 20 ohms load A-Weighted
Frequency Response	5Hz-100kHz, -1dB (-0.03dB at 20Hz/-0.07dB at 20kHz)
Output Impedance	3 ohms
Output Power	4W at 20 ohms

DAC Section
Sample Rate	16 - 32 Bit
	44.1kHz, 48kHz, 88.2kHz, 96kHz 176.4kHz, 192kHz
System Support	Windows XP/Vista/7/8/8.1 USB2 driver requires installation 352.8kHz, 384kHz, Supported by Mac only Native support for Mac OS 10.6.4 and above
Gain	Low=0dB, Mid=10dB, High=20dB

Added 2015

Audio Research DAC9 US$ 7,500.00

USB2.0HS 44.1 to 384kHz, DSD, 2xDSD; RCA, BNC, XLR 44.1 to 192kHz; TOS 44.1 to 96kHz.

TUBE COMPLEMENT (2) 6H30 dual triodes.

AURALiC Vega US$ 3499 / € 3299

The purpose of Femto master clock is to give DAC an ultimate clock with extremely low jitter and phase noise. It utilizes aerospace grade crystal oscillator, ultra low noise linear power supply and temperature compensation technology to generate master clock with extremely low jitter performance at 82 femtoseconds(0.082 picoseconds). What's more important, the phase noise which affect sound quality a lot has been dramatically reduced to -168dBc/Hz.

Source: technical specs AURALiC Vega

Frequency Response: 20 - 20KHz, +/- 0.1dB*
Signal/Noise:126dB, 20Hz-20KHz, A-weighted
THD+N:<0.0003%, 20Hz-20KHz at 0dBFS
Dynamic Range:130dB, 20Hz-20KHz, A-weighted

Digital Inputs
1*AES/EBU
2*Coaxial
1*Toslink
1*USB 2.0 buffered by ActiveUSB™

Analog Outputs
1*Balanced(output impedance 2.2ohm)
1*Single-ended(output impedance 50ohm)

Supported Digital Formats
All PCM from 44.1KS/s to 384KS/s in 32Bit (352.8KS/s and 384KS/s USB only)
DSD64( 2.8224MHz) and DSD128(5.6448MHz) - 'DoP V1.1' standard, USB only

My listening impression can be found here

Ayre QB-9 US$ 2750.-

The company that made USB audio salonfähig in 2008 employing asynchronous USB.
Later support for UAC2 ( > 96 kHz) and DSD where added.

The QB-9 is no longer in producton.

Ayre White paper