FDA-2A AD1955-WM8805 DAC kit launched now

September 14th, 2012

Major highlights:

1. Use AD1955 and WM8805 key parts with single end output.

2. Same super sound discrete IV converter used in the FDA-1, & FDA-1B.

3. Natively support up to 24bit/96k with NOS module.  Support 24bit/192k with AD1896 ASRC module (sell separately).

4. Maximum 4 digital input and one I2S input (total 5).  Default control board provided will control total 4 inputs only (either 3 digital + 1 I2S or 4 digital input).

5. Compatible with many USB2.0 24bit/192 modules: Tested Xmos reference design and Amanero USB2.0 to I2S module.  Interface board to Amanero USB2.0 to I2S  module with or without “Isolator” will be released soon.

6. Control bus for AD1955, WM8805 and other signals are provided for future expansion into fully software mode.

7. DSD input bus is provided for future upgrade.

Details in the manual below:

1955V3_1DAC Manual_r1

Go to Store page if you want to buy this kit : http://www.fetaudio.com/store


AD1955+WM8804/5 SE DAC – launching soon!

August 14th, 2012

This is a single ended DAC using AD1955 DAC and WM8804/5 receiver.  Here are some photos of different versions:

V1.0: FDA-1B with AD1955 DAC chip hardwired on a SSOP board.

V2.0: WM8804 + AD1955 with 3 digital input and one I2S.

V2.1: WM8804 + AD1955 with 4 digital input and one I2S.

V3.0: WM8805 + AD1955 with 4 digital input and one I2S.

V3.1: To be made soon.

On the V3.0, some jitter is measured and the result is quite good.  See attached pdf document:


Note that there are connectors at both the AD1955 and WM8805 chips for the control bus and thus software mode can be turn on if necessary.  This DAC board is really flexible for future expansion. DSD bus socket is also reserved for the AD1955 (SCLK, DSD-Left, DSD-Right, DSD-Phase).  Thus this DAC board is able to experiment on DSD input and also mono mode of AD1955 if a software controller is available.


WM8804 to CS8412 converter board for D1V3 & D1V33 new upgrade

July 23rd, 2012

I have sold hundreds of D1V3 & D1V33 few years ago but I have not forgot continue support for this classical DAC using the best R2R PCM63 DAC chips and Jfet IV common gate topology.  There is a new life to the old classic DAC if you upgrade the receiver from CS8412, CS8414, or DIR9001 to WM8804 which many diyers as well as hi-end audio professionals are all agreed to its best sound performance.  Now this WM8804 to CS8412 converter board is available for sales for just HK$250 net (about US$32).  It is fully assembled and tested with no extra shipping and paypal fee.  I believe it is the best news for all D1V3 and D1V33 users as well as other DAC users because this converter board can output 4 digital modes and thus it can meet most DAC technical needs.

16-bit Right-Justified Mode
24-bit Left-Justified Mode
24-bit I2S
16-bit I2S

Please take note that there is a chance that this converter may not work perfectly or even not working in other DAC platform as there is no 100% compatibility due to different chips in different time of history.  But as usual, I shall advise my best guess after reviewing the DAC circuit before you buy and provide remote trouble shoot support as usual.  So take your own risk when using this in other DAC and I will not accept any return unless the converter is DOA.

Technical details: WM8804 to CS8412 Converter Board Technical Details 3

8804_8412 circuit diagram

FDA-1B + Apple AirPort Express = Wireless “AirPlay”DAC

July 22nd, 2012

Having understood DIYAUDIO member Alex_twn to modify an Apple AirPort Express to output I2S signal to converter FDA-1B to a wireless “AirPlay” DAC, I have not done anything for more than a year.  The main reason is that the US$99 AirPort Express will become useless with Zero second hand value after modifications. Secondly there is no clear indication of the position of the I2S signal inside the AirPort Express circuit boards and tracing the circuit will be difficult for many DIYers.  Thirdly the quality of the internal Master clock jitter of the AirPort Express is still unknown!  Since the AirPort Express has an Optical Digital output socket in optical mini plug format (shared with the analogy output), there is a simple solution to use optical connection between AirPort Express and FDA-1B.  With the WM8804 input receiver quality in FDA-1B, the sound performance will sure has very high assurance level.

Here is my version of wireless FDA-1B DAC playing from a 4 years old notebook with winxp & iTunes.  I use the Airport Utility for windows version 5.5.3 due to my windowXP version. Also I create a new wireless network for the AirPort Express so that it will not increase too much wireless traffic for my original D-Link wireless Router DIR-652 (note this router is connected to internet via a boardband modem).  The connection between AirPort Express and DIR-652 is by a Lan Cable.  With this connection, both the wireless networks can also be able to access internet.  Note that the Optical cable must be one end with mini plug for AirPort Express and the other end with square plug for FDA-1B Optical input.  The total cost of upgrade is only US$115 and it is really a simple upgrade relative to the XMOS solution!  Awesome, it is wireless for both PC and Mac platforms!!!

New FDA-1B Full Balance PCM1794A DIY DAC kit

July 7th, 2012

See Store page for NEW PRICES.  http://www.fetaudio.com/store


This FDA-1B PCM1794A DAC is an upgraded version of the obsolete FDA-1 Single Ended DAC.  FDA-1B has been developing for 1.5 years since FDA-1 was selling. More than 7 version PCBs have been tested before launching to DIYers. It has improved all the weaknesses of FDA-1 and added additional features and functions to enhance the sonic performance and flexibility of the design. Thus it is a more complete and mature design with separate Front Panel control board, I2S input via RJ45 socket and optional ASRC function via daughter board plug-in!


Since it is a DIY DAC and thus most of the parts are selected to be through-hole parts except the ICs and some film capacitors.  In fact most of the film capacitors pad are designed with both SMT (Surface Mount Technology) and TH (Through Hole) pads/holes and thus user can make a change in case better parts is available on hand.  In the I/V section, all TH resistors and some filter capacitors are also provided with a SMT pads in case people want to try the SMT parts.  For the digital section TH resistor pads can also be soldered with a 0805 SMT resistor due to its pitch is 2.54mm. Thus this PCB design is really remarkable and flexible for DIYers to experiment with different types of part for sound tuning!


For the Front Panel control board, it is mainly SMT parts with TH for LEDs and sockets.  Thus it provides a good basic training for all DIYers for SMT soldering.  In fact, SMT parts (with size 0603 and above) are easier and faster to hand solder than TH parts after managing the skills.  What you need is just a 5x magnify glass with stand, small head tweezers, 0.4mm to 0.5mm diameter solder wire and your two stable hands.


New update manual Rev 2: FDA-1B DAC Manual_r2a

This file help to locate all difficult to find resistors, capacitors and diodes: 15c-Part_Location

Go to Store page if you want to buy this kit.

Here is some photos of the FDA-1B DAC kit.

Note that ONE type of I2S input daughter board with RJ45 socket will be provided free.  There are 3 type RJ45 pin assignment boards that can be selected during order – Fetaudio, Kingrex and M2Tech.

The pin assignment can be found in attached document: