Jump to content
UFN

Soekris discrete R2R DAC?

Recommended Posts

Anyone already bought this one and/or seriously considering it? Seriously tempted to try one against my M-Dac with the added bonus that it could drive my T1s directly :)

 

dam1021_top.jpg

 

More info: 

 

http://soekris.com/products/audio-products/dam1021.html

 

https://hifiduino.wordpress.com/2015/01/30/building-soekris-r-2r-dac/

 

and a couple of gargantuan diyaudio-threads  ;D

 

 

//UFN

Share this post


Link to post
Share on other sites

I'm not a fan of the clock generation but all the other features look solid. Nice possibilities with both buffered/unbuffered outputs.

Share this post


Link to post
Share on other sites

Definitely interested in reading your honest and sometimes rough opinions upon this suspect.

Share this post


Link to post
Share on other sites

It looks like an interesting DAC (output taken directly off the R2R for single ended), I've been following it for a while. There is an issue with the current firmware (this should be updated according to Soren)- there is DC surge when switching sampling rates and two people have fried their speaker drivers. So be sure to manually mute before you do that.

Share this post


Link to post
Share on other sites

These plops occur at Fs change when using certain USB/I2S interfaces and aren't harmful to your speakers. One guy fried his speakers by directly connecting the DAC to a 400W amp. All in all a reasonable thing to do, only if the DAC doen't lose it's connection to the potentiometer. Which it did (prototype setup, less than optimal soldering...) and gave the speakers a taste of that class D glory.

 

As for the other guy - he somehow damaged the SMPSU. Sure, there are still kinks to iron out, but it is to be expected. Fortunately the DAC has a serial port which can be used to reprogram its firmware.

Share this post


Link to post
Share on other sites

It lives. Sounds very nice. The Amanero interface causes drop-outs and nasty plops on Fs change, which isn't very nice. The word is that a certain Chinese USB->I2S interface by one Diyinhk doesn't behave that way.

 

9FficSV.jpg

Edited by RudeWolf
  • Like 2

Share this post


Link to post
Share on other sites

Nice RudeWolf.

Not evererybody reported loud plops when changing Fs with the amanero (see dimdim post and video). I am wondering if it has to do with the drivers (?). I guess i'll find out as son as I get the amanero.

Share this post


Link to post
Share on other sites

Great find, thanks for the mention! I've been looking at doing my own FPGA Spartan driven R2R DAC, and here it comes in a nice package. I'll see if he's willing to share his VHDL/Verilog for expert hacking. 

Share this post


Link to post
Share on other sites

VqZpMiD.jpg

Got mine running yesterday with xmos usb-i2s, sslv +/- 12 PSU and stock firmware (still waiting for my usb-serial to arrive).

My first impression is this DAC has really clear sound, decent treble and mid. Yet the soundstage isn't very deep and the bass is not adequate. 

My comparison is based on the same amp and headphone and comparing r2r to my forssell mdac-2

Share this post


Link to post
Share on other sites

An acquaintance of mine did a series of tests and measurements on his DAC and it turned out that current filters are less than optimal. To get the best sound try feeding in as high resolution signal as you can.

 

I'm waiting for a new set of filters to come out.

Share this post


Link to post
Share on other sites

Just swapped out the digital filter on my DAC. I consider it to be a must! So far the best one for me was MB1 by TNT on DIYA.

Share this post


Link to post
Share on other sites

Just swapped out the digital filter on my DAC. I consider it to be a must! So far the best one for me was MB1 by TNT on DIYA.

What kind USB RS232 did you use?

Mine from adafruit doesnt seem to get the job done right.

Share this post


Link to post
Share on other sites

Surprisingly, many current motherboards have RS232 support built in to the motherboard. If you're using a desktop, check the manual and you might just need to buy header off of eBay.

Share this post


Link to post
Share on other sites

I bought a trendnet USB-RS232 from amazon, it works well with soekris's R2R.

With new firmware and NOS filter, Ive be able to do all the conversion and upsampling with my HQplayer.

The bass is back although still not quite perfect.

Also running in NOS reflects filter changes in HQplayer very well.

Share this post


Link to post
Share on other sites

I wonder how it would do with a balanced tube output stage. Circuit ideas anyone?

 

The "Broskie cathode follower" lends its self well to balanced drive.

Build 2, and hook them up out of phase.

 

broskie%20cathode%20follower.png

 

You could also build a simple long-tail-pair output stage with a robust small-signal tube (5687, 6h30, etc) and transformer couple to the output. If you want to get fancy (and why not?) use a blumlein garter instead of a LTP. 

Share this post


Link to post
Share on other sites

.. or check out some of Allen Wright's output stages.

I have never heard a tube output stage for as DAC that I really liked. Transformers and solid state seemed to always to better, but I am all for experimentation!

Share this post


Link to post
Share on other sites

sNnLH0W.jpg

Hooked up r2r with a beaglebone black.

BBB is using master clock feed by r2r.

Sweet lil setup of a streaming box

Share this post


Link to post
Share on other sites

 

Hooked up r2r with a beaglebone black.

BBB is using master clock feed by r2r.

Sweet lil setup of a streaming box

 

I was thinking of doing same. Do tell, how'd you wire it up? Could you put up a table?

Share this post


Link to post
Share on other sites

Soekris R2R connected to the Raspberry Pi2 (RPI2)

 

post-4645-0-34127300-1432788574_thumb.jp

Soekris integrated in to existing Logitech Media Server setup with 2 existing RPI2s and 2 squeezeboxes.

 

Ipost-4645-0-29031600-1432788773_thumb.jp

 

In the background is the LMS playlist manager, in the foreground is the player control app.

 

 

 

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

×