USB9023 (DIY kit)

USB9023::What is it:

The USB9023 is USB audio class interfaced ESS Technology ES9023 DAC. An Atmel AT32UC3A3256 provides the USB interface to the 24bit ESS Technology digital to audio converter. The unit is powered from the USB port and has 2 single-ended RCA outputs.

The USB9023 with the optional enclosure is a nice combination for those who like to take their music with them. The USB9023 will drive high performance headphones such as 250 ohm Beryerdynamic DT880 to a comfortable listening level. Note:: The USB9023 does not have a builtin hardware volume control

Firmware for the AT32UC3A3 is experimental and constantly being improved. Code can be found in the SDR-Widget google group or you may download the latest code branches from the GIT repository

Hardware Features:
  • Compact 110mm X 60.5mm board
  • Powered from the USB port or optionally you can supply 5vdc to the DAC separately.
  • Processor firmware can be updated by the user.


The ES9023 is a 24bit DAC with 112db dynamic range with sampling to 192k. Output is quoted as 2vrms.

Build difficulty:

The kit uses 0603 and 0805 sized SMT components and has a LQFP144_20 cpu. The kit requires a steady hand and a measured approach to building. It is not impossible for a beginner to build the kit but it is not recommended. Currently, there are no 'instructions' on how to assemble the board and no hand-holding is provided. Schematics and component placement are the only aids provided.

The kitting system is rudimentary but functional.

Prices and Ordering:

Kit is sent in a bubble mailer via first class mail. Delivery time is 2 weeks in North America to over 4 weeks in some parts of the world.

This model has been discontinued


A document archive containing schematics and board layout for the original kit is located here.
Documentation for the RevA version is located here.

Assembled USB9023 DAC.