A gyári leírás. A QNKTC honlapján már csak az utódja lelhető fel.

USB-I2S Module and Analog Board version 1.1
The USB-I2S Module and AB-1.1 give you open source USB audio in a modular design. It even comes in a nice enclosure. We encourage you to play with it, change the code and modify the hardware.

The kit is part of the Audio Widget open source project. It is a fork of the SDR Widget project. Homepages are found here:
http://code.google.com/p/sdr-widget/
https://groups.googl...p/audio-widget/
There's a major thread at diyAudio. Please see the FAQ for a list of particularly interesting posts!

So, what does it do?

It plays music pretty well, right out of the box
Open source firmware
Open source electronic schematics
Asynchronous USB Audio
USB Audio Class 1 and 2
24/44.1 and 24/48 stereo on Windows (working on more sample rates)
24/44.1, 24/48, 24/88.2, 24/96, 24/176.4, 24/192 on Linux and Mac
A USB-I2S module you can modify through a bootloader, no hardware programming tools required
An Analog Board which plays well but which has headers etc. for easy modding

USB-I2S Module
The module uses the Atmel AVR32 AT32UC3A3256. It includes everything you need to go from USB on one side to I2S on the other side. The board has an LDO with the option of VBUS or local powering. In addition it has plenty of IO for functions that may become usefull in an audio DAC. There is support for:

Atmel boot loader for easy firmware upgrade without hardware tools
JTAG header for backup programming
Character LCD
UART
SPI and I2C
12 GPIO pins
Sense line for external power

Analog Board 1.1
AB-1.1 is the motherboard for the USB-I2S module. It includes all the analog functions for audio playback. It is designed to be a fully functional and good sounding board. But it has not been tweaked and optimized for the very best in analog Hi-End performance. The ES9023 output filter capacitors are not assembled. Some people think that sounds good, others believe the caps should be there. With AB-1.1 you can try out different options. Everybody is welcome to start out with this board and make an AB with their favourite power / DAC / IVC etc. AB-1.1 includes:

Golledge high-quality XOs at 22.5792 and 24.576Hz
ESS ES9023 DAC
Low-noise 3.3V LDOs ADP151
Sanyo OS-CON capacitors at critical loads
RCA (phono) stereo output
Headers for alternative power supply designs
Unpopulated connectors for RS232, LCD etc.
Bootloader buttons so you don't have to pop open the box to reprogram the MCU