Soekris: Sonics? Comparisons to? & Other Stuff - Page 2 - 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
Reply
 
Thread Tools Search this Thread
Old 18th July 2016, 02:05 PM   #11
diyAudio Member
 
Join Date: May 2010
Location: North Texas
Blog Entries: 4
Quote:
Originally Posted by bear View Post
I'm in agreement that the laser trimmed resistors on a chip are doubtless almost perfect. But I think the justification for the R-2R in the Soekris design - from what I have gathered trying to read through some of the threads - is in terms of the 28bits of depth and the flexibility of being able to download various filters in firmware. Oh, and the ability to accept a variety of input types and formats...
Digital filtering is best done on a PC which has vastly more computing resources than a FPGA or other DSP chip. Also, the extra 4-bits don't do any good unless the preceding 24 are perfect. AFAIK, the Soekris R2R does not use a single, precision current source but each segment of the resistor network is powered by the output of a different CMOS latch chip.

If you want 28 bits with laser trimmed resistors, look at the high sample rate PCM project on my blog.
  Reply With Quote
Old 18th July 2016, 02:34 PM   #12
soekris is offline soekris  Denmark
diyAudio Member
 
Join Date: Jun 2009
Quote:
Originally Posted by bear View Post
I'm in agreement that the laser trimmed resistors on a chip are doubtless almost perfect. But I think the justification for the R-2R in the Soekris design - from what I have gathered trying to read through some of the threads - is in terms of the 28bits of depth and the flexibility of being able to download various filters in firmware. Oh, and the ability to accept a variety of input types and formats...
Yes, the whole point of doing my discrete R-2R design is to get an updated version as development of R-2R chips for audio stopped 20 years ago. With support for higher clocks, more bits, DSD and programmable filters.

Yes, you can find old stock, or you can use expensive industrial DAC chips, or you can parallel multiple slower chips. But with discrete 0.01% smd resistors now priced more reasonable than they used to it's much more cost effective to do a design like mine, especially when using modern automated manufacturing.
__________________
Søren
  Reply With Quote
Old 18th July 2016, 02:35 PM   #13
expert in tautology
diyAudio Member
 
bear's Avatar
 
Join Date: Apr 2002
Location: New York State USA
I'm interested in being able to play redbook CDs and have the ability to play ripped files at hi-res from a computer.

Given that all the CMOS chips are powered from the same source, I'm not clear if in practice there is any non-linearity introduced beyond the tolerance already present in the resistors. Or if that actually matter much in terms of what is heard.

These technical points are interesting, but only to the extent that there is a bearing on the resulting performance and so to the way the dac sounds.

I'm mostly interested in what is being heard and in what system context.
__________________
_-_-bear
http://www.bearlabs.com -- Btw, I don't actually know anything, FYI -- every once in a while I say something that makes sense... ]
  Reply With Quote
Old 18th July 2016, 02:48 PM   #14
expert in tautology
diyAudio Member
 
bear's Avatar
 
Join Date: Apr 2002
Location: New York State USA
So, going back to post #10, does a "rev list" exist??

Would be useful.
__________________
_-_-bear
http://www.bearlabs.com -- Btw, I don't actually know anything, FYI -- every once in a while I say something that makes sense... ]
  Reply With Quote
Old 18th July 2016, 06:44 PM   #15
diyAudio Member
 
wushuliu's Avatar
 
Join Date: May 2008
Location: Los Angeles
Quote:
Originally Posted by bear View Post
So, going back to post #10, does a "rev list" exist??

Would be useful.
None that I'm aware of, you'll just have to search the main thread. Once you do, you'll see that most of the major mods you think might be needed are no longer necessary.

Sounds to me like you should build one and compare yourself. Given its popularity you'll have no problem reselling it if you are not satisfied.
  Reply With Quote
Old 18th July 2016, 09:19 PM   #16
diyAudio Member
 
Join Date: Feb 2008
Location: Chicago, Illinois, USA
One problem with asking this question about DIY stuff in general, and this DAC in particular, is that everyone is going to have a different build. So when someone makes a comment about the DAC (good or bad), is it due to a fundamental feature/problem with the unit itself, or the user's particular build and/or any attempted mods?

And I think out of the box the Soekris DAC has immense flexibility, so even if you take modding out of the picture, simple build variation is huge. You can direct-connect an appropriate transformer, get a cheap I2S or or SPDIF device off ebay and be done. Or you can get fancy with ultra-regulated power supplies and super-duper inputs, or even parallel two boards as I'm attempting to do... and don't forget the custom filters!

That said: here's a brief writeup I did on a different DAC (tda1387 x8). I'm still not done with my Soekris DAC (meaning I didn't spend as much listening time with the initial Soekris build as the tda1387x8), but with a little salt, the comments I made about the tda1387 x8 also apply to the Soekris. My initial dam1021 build was fairly simple: v3 board (no mods), Amanero USB intput, R-core transformer, DIYINHK +/-12V regulator.

I've already acquired a second dam1021 board and am (slowly) working on a dual mono balanced build.
  Reply With Quote
Old 18th July 2016, 09:36 PM   #17
Eldam is offline Eldam  France
Banned
 
Join Date: Sep 2012
Location: France
Is there a subjectiv scaling by the owners of the prefered stock filters and diyed ones ?

Btw, the OEM board is a great idea.
  Reply With Quote
Old 18th July 2016, 10:24 PM   #18
diyAudio Member
 
abraxalito's Avatar
 
Join Date: Sep 2007
Location: Hangzhou - Marco Polo's 'most beautiful city'. 700yrs is a long time though...
Blog Entries: 145
Send a message via Yahoo to abraxalito
Quote:
Originally Posted by bear View Post
I'm interested in being able to play redbook CDs and have the ability to play ripped files at hi-res from a computer.
You might give some consideration to having two DACs, each optimized for those tasks. AMR has applied this within their digital products, there are two DACs within - one optimized for RBCD and the other for 'everything else'.

Quote:
Given that all the CMOS chips are powered from the same source, I'm not clear if in practice there is any non-linearity introduced beyond the tolerance already present in the resistors. Or if that actually matter much in terms of what is heard.
There's at least some anecdotal evidence that linearity in the classic (DNL, INL) sense doesn't matter as much as is generally supposed. For example the TDA1543 has desperately poor linearity but is relatively highly rated subjectively.

It seems from my own research that there's a blind spot shared amongst DAC developers, no-one that I've seen has given much importance to dynamic performance. Not even Mike Moffat who's arguing strongly that a DAC requires excellent INL and DNL (his flagship using an AD device which is probably the best out their in these terms) has talked about dynamic performance other than 'a deglitcher is required' with that DAC. The popularity of NOS DACs to me indicates dynamic performance is an issue, the importance of which isn't regarded as highly as it should be.
__________________
The heart ... first dictates the conclusion, then commands the head to provide the reasoning that will defend it. Anthony de Mello
  Reply With Quote
Old 18th July 2016, 11:39 PM   #19
soekris is offline soekris  Denmark
diyAudio Member
 
Join Date: Jun 2009
Quote:
Originally Posted by bear View Post
As long as Søren is looking on, may I ask a few questions?

Briefly, in terms of the practical changes what has changed V1 --> V4?
Or another way, why would one want a V4 if one had a V2?
Are there "mods" to the circuit that were suggested that became incorporated, that if one had the earlier version one would likely want to do?
dam1021 v1 - The first one, really need the vref mod
dam1021 v2 - vref fixed, improved power on/off mute
dam1021 v3 - custom resistors, more vref capacitors
dam1021 v4 - new output buffers

v2 might improve with a little more vref capacitance, otherwise no mods are needed on v3 & v4. You should of course always use latest firmware.
__________________
Søren
  Reply With Quote
Old 19th July 2016, 12:47 AM   #20
expert in tautology
diyAudio Member
 
bear's Avatar
 
Join Date: Apr 2002
Location: New York State USA
Ok, thanks Søren. Good info.
Why the change in the buffers??


-------------------



As I said at the top I am more interested in what the sound "is".

Time, time, time is not on my side.
So, committing to a build has to be a seriously considered and a pretty certain and clear path.

I'd prefer to buy someone else's if only to see what it is/was, at least to get started.
have yet to see one for sale!
gave a PM to someone who has a post up now, but they seem to have not checked back in, it's been a week or more.
The key is to make some sort of determination, which is the aim of this thread anyhow.

There seems to be an awful lot of raspberry/arduino control work, input boards, muting boards (not needed any longer???), power supply mods. No desire at this point to need to become proficient with the uproc boards! Too steep of a learning curve just to make a DAC do things...

Here's an example - from another forum's post regarding his build and you can see the comments and their significance (yes I gather the shift register PS issue is more or less solved now).


"- Shift reg power bypasses (added rather ocd level of capacitance for one per each shift reg + some additional ceramics). This should be sort of fixed on the newer boards, still more further bypasses usually help (confirmed in some posts by fellow DIYA modders). This one gave most impact on dynamics and 'clean slam', background feels darker - 10 to 15% better
- 1x Salas Ref-D powers clean side of USB-I2S Better imaging and better defined transients - 2% better
- (1x Salas Ref-D powers onboard osc)* Better imaging and better defined transients - 1% better
- Salas BiB does bipolar main dc rails at 7 V or something Smoother, cleaner, more 'refined' - 5 to 10% better
- Removed main psu side from the board (not needed now) Not much difference in sound
- Removed output buffers, can't say if it made a difference, but I'm not using those
- Latest Filters by Spzzzkt Stock filter should not be used at all, it's lo fi. "




Sure wish those folks who have built them up would show up and say what they found and what they think...
__________________
_-_-bear
http://www.bearlabs.com -- Btw, I don't actually know anything, FYI -- every once in a while I say something that makes sense... ]
  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
Based on sonics... which do you prefer ? Mooly Everything Else 757 8th May 2014 11:25 AM
IMAX Sonics Speakers Fiat1 Multi-Way 8 4th May 2012 09:47 AM
Best tube/sonics ailouros6 Tubes / Valves 3 2nd May 2010 07:42 PM
Vintage Sonics Speakers pezza89 Multi-Way 14 26th January 2008 05:54 AM
spring cleaning FREE STUFF just pay shipping plus wtb/wtt ibook stuff relientk4life06 Swap Meet 3 24th May 2006 03:32 AM


New To Site? Need Help?

All times are GMT. The time now is 03:38 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