Reference DAC Module - Discrete R-2R Sign Magnitude 24 bit 384 Khz - diyAudio
Go Back   Home > Forums > Commercial Sector > Vendor Forums > Vendor's Bazaar
Home Forums Rules Articles diyAudio Store Gallery Wiki Blogs Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Vendor's Bazaar Commercial Vendors large & small hawking their wares

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
Reply
 
Thread Tools Search this Thread
Old 22nd July 2014, 01:44 AM   #1
soekris is offline soekris  Denmark
diyAudio Member
 
Join Date: Jun 2009
Default Reference DAC Module - Discrete R-2R Sign Magnitude 24 bit 384 Khz

I have been working on a little side project, now it's time to present it for everybody here....

It's a DAC module based on a discrete R-2R sign magnitude DAC design, with FPGA based reclocking and custom digital filters, < 1 ps jitter clock generator, with 28 bit resolution so there is headroom, oversampling up to maybe 3.072 Mhz. Up to 24 bit / 384 Khz input from SPDIF, I2S and USB (via USB to I2S interface board), with isolation on the I2S interface. The board will be very flexible, with digital volume control and filter parameters that can be downloaded, a possibility is also to add digital crossover filters, but that will probably not be ready for first production lots, although the board is firmware upgradable over a simple serial connection.

The basis R-2R network has an output voltage of 1.4V RMS and output impedance of 625 ohm and can therefore drive a lot of things directly.... There is also onboard balanced output drivers that can drive high impedance (>= 300 ohm) headphones directly. The power supply is also onboard, just add a 5W toroid transformer.

It is a small mostly surface mount PCB, and yes, I have working prototypes, see below.... But it's not really something for home assembly, with the FPGA in BGA package and 600 pcs SMT parts.... So yes, if there is enough interest it will go into real production, with sales though two existing online shops in US and EU.

Performance of first prototypes using 0.05% resistors is better than expected, see 1 Khz -1 db and -60 db FFT plots. I believe that the sound quality will be the absolute best, better than any Delta Sigma DAC, in class with discrete DAC's from totaldac and msb technology. And for way way less cost :-)

----

Update on Oct 14,2016:

The dam1021-12 and -05 are in stock again, still rev 4.

Update on May 27, 2016:

Vers. 1.06 firmware with DSD support now available on http://www.soekris.dk

Boards from next production run will be rev 4 and are now in stock, that batch will only be the 0.05% and 0.01%/0.02% resistor version, which will be the only two dam1021 versions available long term. The only other change from rev3 to rev4 is a change in the output buffers, the LME49710/LME49724 is replaced with OPA1602.

Pricing for board rev 4 is:

dam1021-12: USD 295 / EUR 266 (0.01%/0.02% resistor version, in stock)
dam1021-05: USD 195 / EUR 176 (0.05% resistor version, in stock)

Pricing for board rev 3 is:

dam1021-02: USD 265 / EUR 238 (0.02% resistor version, very low stock)
dam1021-05: USD 195 / EUR 176 (0.05% resistor version, sold out)


Shipping cost and any sales tax and/or other local taxes to be added.

They are available to order though two existing webshop:

http://soekris.com/products/dam1021.html for American and Asia markets.
http://www.soekris.eu/shop/dac_modul...for_orders_en/ for EU and European markets.

The main Soekris Engineering ApS (Denmark) website for product and technical information is:

http://www.soekris.dk Please don't email soekris.com or soekris.eu with technical questions....

See also post #901 Reference DAC Module - Discrete R-2R Sign Magnitude 24 bit 384 Khz for a quick drawing with connections.
And post #1108 Reference DAC Module - Discrete R-2R Sign Magnitude 24 bit 384 Khz for SPDIF interface drawing.
And great info here https://hifiduino.wordpress.com/2015...kris-r-2r-dac/
Post #1486 Reference DAC Module - Discrete R-2R Sign Magnitude 24 bit 384 Khz with filter tools.
Post #3276 Reference DAC Module - Discrete R-2R Sign Magnitude 24 bit 384 Khz Firmware revision 0.99 update
Post #3295 Reference DAC Module - Discrete R-2R Sign Magnitude 24 bit 384 Khz more info on 0.99
Post #3108 Reference DAC Module - Discrete R-2R Sign Magnitude 24 bit 384 Khz Official vref modification
Post #3362 Reference DAC Module - Discrete R-2R Sign Magnitude 24 bit 384 Khz More info on vref mods

Anybody can now order the dam1021 R-2R DAC board from the two webshops.
Attached Images
File Type: jpg dam1021_top.jpg (536.4 KB, 30422 views)
File Type: jpg fft_-1db.jpg (172.3 KB, 26442 views)
File Type: jpg fft_-60db.jpg (161.4 KB, 25044 views)

Last edited by soekris; 14th October 2016 at 09:09 PM. Reason: Now taking orders !!
  Reply With Quote
Old 22nd July 2014, 02:41 AM   #2
diyAudio Member
 
Join Date: Oct 2004
Very cool project, soekris!
Count me in for one 0.02% version. Otherwise a 0.05% version is fine for me, too.
A fully assembled board is prefered, otherwise I can also solder the SMT parts myself if you have pre-soldered the FPGA.

However, it seems the analog output portion can't be bypassed. Here in diyaudio many of us have our own flavor of analog stage (opamp, discrete, tube, output transformer, etc). It would be much better and certainly would garther more interest if you could add a jumper for us to use the onboard analog stage or our own analog stage. The real jewel of this design is the digital portion.

Last edited by rredline; 22nd July 2014 at 02:54 AM.
  Reply With Quote
Old 22nd July 2014, 02:57 AM   #3
soekris is offline soekris  Denmark
diyAudio Member
 
Join Date: Jun 2009
Actually yes, the output drivers can be bypassed, the "raw" R-2R DAC outputs before buffering are available on connector J7, at line level voltage and low impedance.

Not that the output buffers are that crappy, a LM49710 driving a LM49724....
  Reply With Quote
Old 22nd July 2014, 03:19 AM   #4
diyAudio Member
 
Join Date: Oct 2004
Quote:
Originally Posted by soekris View Post
Actually yes, the output drivers can be bypassed, the "raw" R-2R DAC outputs before buffering are available on connector J7, at line level voltage and low impedance.
Great! Just saw it. At first I thought JP7 signal is came from opamp but turns out it is from DAC.

Last edited by rredline; 22nd July 2014 at 03:24 AM.
  Reply With Quote
Old 22nd July 2014, 06:12 AM   #5
CFT is offline CFT  United States
diyAudio Member
 
Join Date: Jul 2006
Location: Hong Kong
Very nice!
Please count me in for one 0.02%.
  Reply With Quote
Old 22nd July 2014, 06:31 AM   #6
dex-rex is offline dex-rex  Australia
diyAudio Member
 
Join Date: Feb 2002
Location: Perth
Send a message via ICQ to dex-rex
Tempting! Count me in for a 0.02% version. Freq. graph would be welcome ...
__________________
dex-rex
  Reply With Quote
Old 22nd July 2014, 06:45 AM   #7
diyAudio Member
 
Join Date: Oct 2012
interesting project... I would like to have one although i have 3 dacs already...

Can I ask for the reclocking is using the on board clock or the incoming clock ? Also upsampling can be bypass ?
  Reply With Quote
Old 22nd July 2014, 07:23 AM   #8
tuyen is offline tuyen  Australia
diyAudio Member
 
Join Date: Oct 2008
Send a message via MSN to tuyen
Consider me keen for a board
  Reply With Quote
Old 22nd July 2014, 07:37 AM   #9
diyAudio Moderator Emeritus
 
jean-paul's Avatar
 
Join Date: Sep 2002
Location: Germany
Very nice design, it is quite compact and it is a joy to look at. I think it is the smallest discrete R2R DAC I have ever seen.

Some concern: with a resolution this high and "naked" resistors even some dust can disturb things isn't it ?
__________________
It's only audio. Member of the non modular PCB design committee

Last edited by jean-paul; 22nd July 2014 at 07:40 AM.
  Reply With Quote
Old 22nd July 2014, 07:46 AM   #10
diyAudio Member
 
Join Date: Apr 2008
+1 of the 0.02% version or 0.01% if is not outrageously expensive...
BTW what is the size of the board?

Last edited by Nikola Krivorov; 22nd July 2014 at 07:48 AM.
  Reply With Quote

Reply


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
e18 DAC - 8 channels at 32bit /384 kHz exa065 exaDevices 30 29th June 2012 06:11 PM
384 Khz DAC? SunRa Digital Source 8 2nd October 2009 12:14 AM
24 bit/192 kHz via USB? gentlevoice Everything Else 3 22nd December 2008 07:24 AM
sign magnitude DAC Bernhard Digital Source 0 30th January 2007 02:40 PM
24 bit / 192 kHz Tube DAC questions Overlord Digital Source 4 29th April 2003 06:14 PM


New To Site? Need Help?

All times are GMT. The time now is 07:46 PM.


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
Wiki