ADAT receiver - diyAudio
Go Back   Home > Forums > Source & Line > Digital Line Level
Home Forums Rules Articles diyAudio Store Gallery Wiki Blogs Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Digital Line Level DACs, Digital Crossovers, Equalizers, etc.

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Thread Tools Search this Thread
Old 25th July 2009, 05:27 AM   #1
diyAudio Member
Join Date: Nov 2006
Default ADAT receiver

I made ADAT receiver board, based on AL1402G to output 4 channel I2S.
It looks like working now.
board was made by ExpressPCB, costs $91 for 3 mini boards.

Next I have to modify my CUDA-FIR channel divider to handle ASIO in/out.

I'm using E-MU 1010 PCI + EMU expansion board to accept word sync clock.
Attached Images
File Type: jpg cimg0215s.jpg (89.1 KB, 844 views)
  Reply With Quote
Old 25th July 2009, 05:34 AM   #2
diyAudio Member
Join Date: Nov 2006
here is schematic.
major parts are below, very simple.

U1 DS1812-5 DS1812-5+CT-ND
U2 LP2950-5 LP2950ACZ-5.0NS-ND
U3 LP2950-5 LP2950ACZ-5.0NS-ND
U5 AL1402G AL1402G
U6 74HC04

most expensive one is of course AL1402G, it costs about $24/chip.
bought from

Also I bought masterclock generator. I will test 44.1kHz sync-mode when I get cable (ordered to Amphenol)
Attached Files
File Type: pdf al1402g_sch.pdf (45.3 KB, 254 views)
  Reply With Quote
Old 25th July 2009, 05:50 AM   #3
diyAudio Member
Join Date: Nov 2006
Photo for LRCK, and SDATA5/6.

Q: what is this board for?
A: to supply I2S x 4 signal, to my full digital 4 way amplifier.

Q: why ADAT, not LAN?
A: I tried some network-CPU, like Atmel NGW100, NetBurner, AVR32, and tired. I could not build reliable, fast enough, stable multichannel LAN DAC. and these hardwares are too much (too many ICs).

Q: limitation?
A: 44.1kHz / 16bit / 8channel. It's good enough for me, If you want more, ADAT can be multiplied.

Q: what are you using as player?
A: iTunes / WMP / my own - etc. The output goes through "Virtual Audio Cable" to my FIR channel divider, then output to device by portaudio interface. This route will be changed to E-MU patchMix, it will handle ASIO i/o.

Q: board? or gerber?
A: ExpressPCB will not make gerber file, board file can be sent by eMail on request. (as is!)
Attached Images
File Type: jpg cimg0218s.jpg (88.4 KB, 735 views)
  Reply With Quote
Old 25th July 2009, 07:24 AM   #4
diyAudio Member
soundcheck's Avatar
Join Date: Mar 2005
Location: DUS
Hi Koon.

44.1/16 only! Hmmh. That's not very much.

Ever thought about building a PCI-E interface with separate powersupply?
  Reply With Quote
Old 25th July 2009, 09:56 AM   #5
diyAudio Member
Join Date: Aug 2008
i see 3000 ps jitter too as limitation unless you use SRC or slave the source somehow to the endpoint .
  Reply With Quote
Old 25th July 2009, 04:51 PM   #6
diyAudio Member
Join Date: Nov 2006
Q: how to get 24/96?
A: use more expensive ADAT board, like RME.
2 ADAT channels can supply 24/96, 4way.

Q: dedicated board, separated power?
A: There is generic PCI IO board,
and I have FIFO-to-I2S FPGA. (with separated power, only one clock here)
so it's possible but total building / price is not attractive than ADAT.
Power supply is separated on PC and on my ADAT receiver-Amplifier.

Q: Jitter?
A: Yes I purchased ARTGEN WORD SYNC clock generator, it's spec says < 100ps.
ADAT itself will be some thousands ps. if 1/30 improvement make sound quality, I can try more expensive clock generator.

TAS5518 re-sample signal and make it's own PCM data to convert PWM.
So I'm not expecting ARTGEN can make some change.
  Reply With Quote
Old 25th July 2009, 05:59 PM   #7
diyAudio Member
Join Date: Aug 2008
especially for PWM, jitter is paramount. You need 20 ps for 16bit PCM equivalent perfomance.

You need total rejection of some form, nothing else would do IMHO.

1. ASRC for realtime
2. some sort of streaming (USB or Ethernet) into FIFO buffer with synchronous readout.

these are both known for total jitter rejection, TI has the 4 channel SRC4194 thats suitable for you. It has 28 bit math and 5th order lagrange interpolation preceded by 16x OS .

Heres a good document that 'd help :
  Reply With Quote
Old 25th July 2009, 06:45 PM   #8
diyAudio Member
Join Date: Nov 2006
So, for TAS5518, itself has own clock and SRC,
"32-Bit Processing PWM Architecture With 40 Bits of Precision"
"8x Oversampling With 5th Order Noise Shaping at 32 48 kHz,"
for each channel to prepare PWM signal.

Of course I don't deny <20ps WORD SYNC generator, ASRC, FIFO for your own DAC etc.
  Reply With Quote
Old 25th July 2009, 07:07 PM   #9
diyAudio Member
Join Date: Aug 2008
both Intersil and Zetex include an ASRC before their PWM modulator, I doubt you can get clean jitter spectrum like that without sacrificing something , eg. latency using a FIFO buffer.
  Reply With Quote
Old 25th July 2009, 07:27 PM   #10
diyAudio Member
Join Date: Aug 2008
the TAS5518 definately has no ASRC.
  Reply With Quote


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Similar Threads
Thread Thread Starter Forum Replies Last Post
DIY ADC/DAC with ADAT echosystm Digital Line Level 1 8th May 2009 10:34 PM
ac3 and ADAT? noelburke82 Digital Line Level 4 8th March 2009 05:15 AM
ADAT DAC Question kmt Digital Source 24 24th February 2009 02:39 AM
ADAT Format fmak Digital Source 18 24th December 2003 07:24 AM
adat to parallel/usb/pci ANYTHING xdissent Digital Source 1 14th October 2003 10:37 AM

New To Site? Need Help?

All times are GMT. The time now is 06:29 AM.

vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Copyright 1999-2017 diyAudio

Content Relevant URLs by vBSEO 3.3.2