Yoyodyne Consulting
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YC-USB9023 ( DIY Kit )

YC-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:

Performance:

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

Documentation:

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

Logbook

  • Jan 10, 2012
    - Stock exhausted and discontinued board sales.
  • Oct 29, 2011
    - Almost out of boards for kits with only 3 left. I won't do another run of boards until next year.
  • Aug 09, 2011
    - Only 10 kits left.
  • July 27, 2011
    - Assembled and tested the RevA circuit board. No problems encountered.
  • July 19, 2011
    - The Si532 clocks arrived almost 3 weeks early.
  • July 18, 2011
    - Modifications made to the original design. DAC and 74109 are powered by a separated ADP151 regulator. Power to both the DAC and clock/divider can be taken from either the USB port or and external 5v0 supply. The regulators may be bypassed completely and the build can power the circuits with a 3v3 supply of their own design. Capacitors in critical areas have be upgraded to Panasonic Polyment Aluminum SMT devices. Unfortunatley the following additions have increased the cost of the kit to $85 Canadian.
  • May 12, 2011
    - Cases with drilled endplates arrived. The openings are not perfectly aligned but the offset does not interfere with the cable insertion. Thicker, 1.5mm, endplates allow the mounting screws to recess properly.
  • Mar 20, 2011
    - First board assembled. It is possible to hand assemble this board but it does require a light touch with the soldering iron. Current firmware needs to be customised to the board. UAC2 playback is excellent 44.1/88.2/176.4 24bits
  • Mar 7, 2011
    - Protoboards ordered
  • Feb 20, 2011
    - Prelim work completed


Board rendered using gEDA/pcb on Linux

















©2009-2012 Yoyodyne Consulting
Last modified Sat Oct 29 12:38:51 2011