The Well-Tempered Computer

An introduction to computer audio

USB to SPDIF converters

Although it is changing slowly, the audio world is not very computer minded.
If audio gear has a digital connection, it is SPDIF.
All PCs have USB but few (most  of the time the multimedia models) have SPDIF out.
If you want to connect a PC without SPDIF to audio gear with SPDIF input only, a USB to SPDIF converter is the solution.

 

The information below is as supplied by the manufacturer's website.

Anedio U2 US$390

Asynchronous USB to SPDIF converter.

USB class 2 compliant (24/192)

USB receiver by XMOS, Win driver by Thesycon.

Two independent low-jitter crystal oscillators.

Galvanically isolating using a high-speed transformer at the SPDIF output.

BNC connector.

Analog Research Technology - Legato $500.00

  • Asynchronous operation, using Streamlength © technology.
  • 44.1 kHz only
  • Transformer output provides for complete galvanic isolation.
  • Self-contained power supply, draws no power from computer.
  • Extremely low jitter internal clock, provides for highest level of performance possible.
  • True 75 ohm output impedance, with military-grade BNC connector.

April Music - Stello U3 US$ 495

USB Audio Class 2.0 compliant Asynchronous synchronization mode
High Speed Bit Perfect Audio Data Stream up to 192kHz sampling rates
Master clock Super low jitter 2 external clocks
Sampling Frequency 22.5792mHz/24.576mHz for multiples of 44.1kHz/48kHz sampling rates
Resolution Standard sample rates 44.1, 88.2, 176.4, 48, 96, 192kHz/24bits Audio
Input 1 USB 2.0, Type B connector
Processor 32-bit 500Mips XMOS processor
Outputs Galvanic Isolated, Up to 192kHz sampling rates
1 COAX 75 Ohms, Gold Plated RCA Connector
1 AES/EBU 110 Ohms, Neutrik XLR Gold plated contacts
Lock indicator LED on the front panel
Platform Support Customized Windows Driver : Windows XP, Windows Vista, Windows 7
Natively supported by Apple Mac OS X
Dimension 100 X 36 X 100mm (WHD)


Audiophilleo 1 $895.00

  • Asynchronous USB
  • 192Khz 24bit sample rate capable
  • Ultra low jitter SPDIF output (<15ps rms)
  • Direct connection to DAC without expensive cable (BNC)
  • Fixed Frequency Clocks
  • Windows, OSX, and Linux compatibility with Dual Driver capability
  • Regenerative power supply which isolates the S/PDIF output stage from USB power
  • Fully differential ECL galvanically isolated transformer-less output stage
  • Upgradeable firmware
  • Machined cast aluminum case for best shielding
  • Complete immunity to audio vibration even with the loudest playback
  • The included USB and SPDIF cables/connectors are tested for optimal performance. No need to buy additional cables - they won't improve your sound.

Behringer U-CONTROL UCA202 $ 44.99 USD

  • Ultra-flexible audio interface connects your instruments, mixer, etc. with your computer for recording and playback
  • High-resolution 48 kHz converters for high-end audio quality
  • Works with your PC or Mac computer—no setup or drivers required. Free audio recording and editing software downloadable at www.behringer.com
  • Stereo Headphone output with dedicated Level control lets you monitor both input and output
  • Additional S/PDIF optical output for direct digital conversion
  • Powered via USB—no external power supply needed
  • High-quality components and exceptionally rugged construction ensure long life

Measurements by NwAvGuy

Bel Canto REFLink AU$ 1595

  • Asynchronous USB up to 24/192
  • USB driver for Win
  • Output:
    • Coaxial SPDIF on BNC 75Ω
    • Balanced AES on XLR 110Ω
    • LightLink ST Fiber
  • Proprietary 500MHz DSP Asynchronous USB Core
  • Dual Ultra-Low Phase-Noise Clocks
  • Two-stage galvanic isolation
  • Dedicated LNS (Low Noise Supply)

Berkeley Audio Design Alpha USB $1895

  • Input: High Speed USB 2.0 asynchronous connection - type B receptacle
  • Supported operating systems: Apple Macintosh and Microsoft Windows (Alpha USB Windows driver)
  • USB audio class 2 compliant
  • Outputs: switch selectable, coaxial SPDIF - BNC, 75Ω or balanced AES type - XLR, 110Ω
  • Supported sampling rates: 44.1kHz to 192kHz
  • Supported word lengths: up to 24-bit

Great care was taken in the design of the Alpha USB to isolate the noisy computer/USB environment from the digital audio output. The USB receiver and processing are powered by the computer, while the output master clocks and line drivers are powered by a separate isolated linear power supply.
Two key factors combine to achieve the excellent audio performance of the Alpha USB - the unprecedented degree of electrical isolation between the USB input connection and the audio output and the very low noise/low jitter performance of the individually tested audio output master clocks.

Source: Berkeley Audio Design

 

Blue Circle Audio $189.00

A PVC pipe filled with silicon and some unknown parts.

We are not going to tell anyone what IC we use for the conversion and DAC because we want you to judge the USB Thingee by its sonic performance and not by the numbers and specs.

CIAudio Transient MKII Asynchronous USB Converter $699

Input: asynchronous 24/192 USB (Xmos), driver for Windows

 

Digital Outputs:

  • S/PDIF via 75 ohm BNC Connector (Galvanic Isolated)
  • I2S via Mini DIN Connector (Audio Alchemy/Perpetual Tech/Camelot)
  • Differential I2S via HDMI Connector (PS Audio/Wyred4Sound)

Sample Rates Supported: 44.1k, 48k, 88.2k, 96k, 176.4k, 192k up to 24bits

Master Clock Jitter: < 1.0 psec

Analog Output Level: 2V RMS Maximum (Single-ended RCA)

Frequency Response: 0hz to 96kHz

THD + Noise: -89db @ -1dBFS

 

Dimensions: 4.45"W x 2.9"H (including feet) x 5.25" D

Warranty: 5 Year Parts & Labor

CyroParts Sonicweld Diverter $1299.00

USB to SPDIF converter

  • Passes up to 24/96 data via USB
  • No special drivers or software needed
  • Unique internal power supply regulation for optimum performance using USB bus power - no external power supply needed!
  • Aggressive common and differential mode filtration circuit designed for optimum performance using USB bus power
  • All bypass caps are non-microphonic SMT film types
  • Active inrush current management protects USB controller
  • Custom silver-plated six layer circuit boards use of high speed digital design PCB layout techniques, with multiple ground and power planes
  • Custom machined enclosure milled from T-6061 solid billet aluminium alloy with stainless steel constrained layer damping plates
  • Ultra high quality, ruggedized, Amphenol USB "B" input
  • WBT RCA coaxial digital output

Emperical Audio Off-Ramp 5 $1,299

 

USB receiver: M2Tech - proprietary drivers for Win and Mac

Dual clocks for 44.1/88.2/176.4kHz and 48/96/192kHz

 

Outputs:

  • Isolated S/PDIF coaxial – 75 ohm Canare BNC jack
  • AES/EBU – XLR male
  • I2S on RJ-45, Empirical Audio standard (5V, optional 3.3V) output impedance is 120 ohms
  • I2S on HDMI - LVDS format, pin compatible with PSAudio and Wired for Sound DACs.

Options

Firestone Audio Bravo USB/SPDIF converter 159,00 EUR

  • Circuit Structure: Converts and reclock USB and SPDIF (Optical and coax) to SPDIF
  • Fully support to 96kHz / 24-bit digital signal
  • Power Structure : Switching DC-DC regulator, Soft-Start circuit

Supported Formats :

  • USB input : 16-bit, 32kHz / 44.1kHz / 48kHz / 96kHz
  • USB input : 24-bit, 44.1kHz / 48kHz / 96kHz Coaxial / Optical input : 16-bit, 32kHz / 44.1kHz / 48kHz / 88.2kHz / 96kHz
  • Coaxial / Optical input : 24-bit, 32kHz / 44.1kHz / 48kHz / 88.2kHz / 96kHz
  • Coaxial / Optical output : 16-bit, 32kHz / 44.1kHz / 48kHz / 88.2kHz / 96kHz
  • Coaxial / Optical output : 24-bit, 32kHz / 44.1kHz / 48kHz / 88.2kHz / 96kHz
  • Input Select : Auto Select, USB input is highest priority Reclock :
  • Include Fi-reclock® technology to reduce jitter
  • Circuit Protect : Over current protect
  • USB Chip : TENOR - TE0722
  • Receiver Chip : TI - DIR9001
  • Transmitter Chip : Wolfson - WM8804

Firestone Audio RedKey €79,00

24/96 USB to SPDIF converter.

Probably adaptive mode.

Size: High 80.15mm x Width 20.4mm x Depth 18.1mm

 

Halide Design - The Bridge $450.00

  • Asynchronous USB (Streamlength™ )
  • Supported rates - 44.1, 48, 88.2, and 96 kHz (user selectable), at 24/16 bit resolution. (Note: 88.2 kHz currently not supported by Windows Vista / 7.)
  • Power - supplied from USB connection. LC filtered (two pole passive) and down regulated; separate power rails for digital circuitry and master clock.
  • Isolation - output is fully isolated using a high quality digital audio transformer.
  • Connection - 75 ohm, available in BNC (gold center pin) and RCA (Eichmann silver bullet) versions.

Some measurements by Stereophile

Human Audio Tabla Pico US $579 / €380 (including 27% VAT)

USB to SPDIF converter using Hiface EVO drivers (bulk mode).

 

  • Resolution: up to 24 bit / 192 kHz
  • OS driver availability: for Windows & Mac OS X ( hiFace EVO compatibility )
  • Input: USB 2.0
  • Output: 75Ω BNC (optional RCA adapter from BNC)
  • Powering: Built-in rechargeable LiFePO4 battery with ~8 years lifetime without memory-effect
  • Charging: Fully automated from USB power when idle(stop & power off state)
  • Operation time (in "GREEN" battery mode) without charging: at least 12 hours of continuous playback
  • Seamless switching (with LED indication) between the clear battery ("GREEN") mode and battery charging during playback ("YELLOW") mode without any audible glitch. The battery is permanently connected to the circuit, only the charge control switch goes on and off when required. 
  • Charging time: max. 8 hours

The Pico on Head-Fi

John Kenny JKSPDIF MK3 €320

Modified HiFace 24/192 asynchronous USB - SPDIF converter

  • it is completely off-grid, powered from 2 internal batteries (these will last about 24 hours between charges)
  • it is portable - no need for external power supply when listening to audio
  • the SPDIF output stage is now based on the Wolfson WM8804 chip
  • SPDIF signal is now within spec
  • it comes in an aluminium enclosure
  • it now uses a USB type B socket
  • internal battery charger - requires user supplied 9V or 12V DC supply

 

Lindemann

Lindemann USB-DDC 24/192 - € 249,-

 

  • Adaptive mode USB
  • The USB-DDC can be switched between USB Audio Class 1 (up to 24bit/96kHz) and USB Audio Class 2 (up to 24bit/192kHz). Comes with a Class 2 driver for Win.
  • Additional data processing circuit (with data buffering and clock-synchronization) to reduce jitter
  • The grounding system is completely electrically insulated in order to prevent interference from the PC from negatively affecting the hi-fi system.
  • USB powered.
  • low jitter clock (<50ps typical)

 

M2Tech hiFace $150.00

  • Input: asynchronous USB
  • Output: S/PDIF (RCA or BNC)
  • Sampling Frequency : 44.1kHz, 48kHz, 88.2kHz, 96kHz, 176.4khZ, 192kHz
  • Resolution: 16 up to 24 bit
  • Dimensions: 10.2(d) x 2.2(h) x 2(w) cm
  • Power Supply: 5V DC from USB bus

FAQ about hiFace

 

M2Tech hiFace 2 US$ 185

The biggest news is probably that M2Tech decided not to use their proprietary drivers but to using the native mode USB audio drives of the operating system.
It is UAC1 and UAC2 compliant so will work out of the box with Win, OSX and Linux.
For > 96 kHz you need a driver on Win as Win is not UAC2 compliant.
The receiver is by XMOS and the driver by Thesycon.

 

  • Input 1 x USB A type male
  • Output 1 x RCA or BNC female
  • Input USB 2.0 Audio Format with aAsynchronous synchronazation
  • Output S/PDIF Stereo Digital Audio Format
  • Sampling Frequency: 44.1kHz, 48kHz, 88.2kHz, 96kHz, 176.4khZ, 192kHz
  • Resolution 16 up to 24 bit
  • Dimensions 10.2(d) x 2.2(h) x 2(w) cm
  • Power Supply 5V DC from USB bus
  • Weight 50gr approx.

M2Tech hiFace Evo $499.00

Asynchronous operation up to 192kHz is used in conjunction with proprietary drivers which allow for Kernel Streaming, Direct Sound and WASAPI operation.

Sampling frequencies (kHz): 44.1, 48, 88.2, 96, 176.4, 192
Resolution (bits): 16 to 32
Inputs: USB 2.0, supply, master clock
Outputs:
S/PDIF x2 (RCA & BNC)
AES/EBU (XLR)
optical Toslink™
optical ST
I2S (RJ-45)

Musiland Monitor 01 USD $73.95

  • Interface: USB 2.0
  • Maximum sampling rate: 24bit/192kHz
  • Digital output: Optical toslink, RCA and BNC coaxial
  • Digital S/N: 140dB (A-weighted)
  • Digital dynamic range: 140dB (A-weighted)
  • ASIO driver - support Windows XP, Windows Vista and Windows 7

Musical Fidelity Vlink $169.00

24 bit/ 96 kHz asynchronous USB to S/PDIF converter

Optical and coax SPDIF out.

Musical Fidelity Vlink192 $399

24 bit/ 192 kHz asynchronous USB converter

It has both coax and fully balanced digital outputs.  Both are fully galvanically isolated.

M audio Transit $99.95

Input:

  • 24-bit/96kHz USB
  • stereo analogue/optical digital (1/8")

Output:

  • Stereo line/headphone output (1/8")
  • TOSlink optical digital output allows AC-3 and DTS pass-through

Soulution 590 USB converter CHF 3.000

Asynchronous USB converter.

24/192 USB class audio 2.

Driver for Win

 

Digital outputs:
- 1 x SPDIF (RCA)
- 1 x AES/EBU (XLR)
- 1 x Optical (Toslink)

SOtM - dX-USB USD $429.99

Digital Audio Input

  • USB Audio class 1.0
  • 44.1KHz, 48KHz, 88.2KHz, 96KHz sampling rate
  • Max 24bit PCM audio data
  • Sampling rate auto detect and display
  • Bit-transparent operation

Digital audio output

  • Coaxial
  • Optical
  • I2S
  • AES/EBU(option)

Components

  • TUSB3200A for USB interface
  • AK4104ET for digital audio output
  • Ultra high speed RS422 driver for AES/EBU, Coaxial & I2S output
  • Flat chip audio grade resistor for PLL and power circuit
  • PPS film chip capacitor for PLL and power circuit OS-CON capacitor for power circuit
  • Ultra low jitter clock
  • Canare 75Ω impedance RCA bulkhead connector for coaxial output
  • Toshiba TOTX178A TOSLINK optical connector for optical output

The new dX-USB HD has

  • USB2.0 High Speed, USB Audio Class 2.0
  • 16/24Bit 44.1/48/88.2/96/176/192kHz
  • Asynchronous mode operation
  • USB class 2 drivers for Windows

 

 

Styleaudio CARAT-T2 450,00 EUR

Digital Input : USB x 1 (USB input sampling : 24Bit/96Khz)

Digital Output : Optical x 1, Coaxial x 1, AES/EBU x 1

USB signal isolator : Analog Devices ADUM4160

USB power isolator : Analog Devices ADUM5000

Scientific Conversion’s Digital audio transformer for isolated 110ohm balanced and 750ohm unbalanced

Power : USB self power or external adapter

Reclocking circuit & TCXO 10ppm, WIMA, OSCON, 24K gold PCB

Main body size (WxHxD/mm) : 75 x 35 x 131

Trends Audio UD-10.1 USB Audio Converter €179.00

Optical, Coax, BNC, and XLR digital connectors.

Sample rates: 32, 44.1, 48 kHz

Audio format: linear PCM, 16 bits per sample

Wavelength Audio - WaveLink HS 24/192 USB to SPDIF converter $900

  • Streamlength Asynchronous USB
  • XMOS USB receiver
  • Sampling Frequency : 44.1kHz, 48kHz, 88.2kHz, 96kHz, 176.4khZ, 192kHz
  • Bit depth: 16/24
  • Output: S/PDIF (BNC)
    Included is BNC-BNC SPDIF cable and with a mating BNC->RCA adapter
  • Thesycon USB Class 2 Audio driver (Windows)
© Vincent Kars