DIY R-2-R DAC thread.

[gentlevoice]

Hi all,

I've been thinking about this for some time now - designing & building a quite precise R-2-R DAC based on e.g. shift registers & maybe flip-flops - and would like to hear if some of you would be interested in joining in on a collaborative DIY design?

If so I can post some of my ideas ...

Cheers,

Jesper

 

[jean-paul]

It seems a fellow countryman thought the same:

http://www.diyaudio.com/forums/vend...crete-r-2r-sign-magnitude-24-bit-384-khz.html

DIY or half-DIY, it is an impressive piece of equipment which will be hard to compete with.

 

[gentlevoice]

Hi Jean-Paul,

DIY or half-DIY, it is an impressive piece of equipment which will be hard to compete with.

... yes, it is indeed impressive ... And I won't be interested in competing with what Søren has accomplished - my inspiration in this is probably more in the direction of the TotalDAC (to the extent that I'm familiar with it) with up to 1.536 & 3.072 MHz sampling rates so that - with few changes - the design is also future proof. And more as a "typical" design where everyone can make their own implementation.

Cheers,

Jesper

 

[abraxalito]

Certainly very interested to follow and contribute ideas towards getting it to sound good. The reference voltages of the Soekris DAC were it seems the most critical point of focus.

 

[gentlevoice]

Certainly very interested to follow and contribute ideas towards getting it to sound good. The reference voltages of the Soekris DAC were it seems the most critical point of focus.

... pleased to hear that, abraxalito ... and, yes, my guess also is that the reference voltages are key ...

Will post a couple of my thoughts tomorrow ... (please all feel welcome to post if you have ideas)

Cheers,

Jesper

 

[abraxalito]

Given that reference noise is key to good sound quality, and that the shift-registers/flip flops are going to constitute a code-dependent loading on those references, my suggestion would be to build in self-cancellation (perhaps using additional SRs/FFs) so that by design the loading on the Vrefs is constant. Rather like a current-invariant classA amplifier presents a constant load on its power supply no matter what the signal is.

 

[Mark Johnson]

Attention: diyAudio member jean-paul:

Your Private Message box is full and this prevents me from replying to your earlier message.

 

[hollowman]

R-2-R DAC with flip-flops, etc.

I've been thinking about this for some time now - designing & building a quite precise R-2-R DAC based on e.g. shift registers & maybe flip-flops ...

Not sure how original or innovative ("his") discrete R2R design was (he posted no details or schemas) but Yeo from diyparadise bragged about "his" Discrete Monica here (back in 2011/12):
DISCREET [sic!!!!] MONICA:diyparadise

It was R2R discrete (partially??) flip-flop based (tho' I see a lot of Rs at the bottom):

 

[gentlevoice]

Hi all,

My apology ... I'll have to pause my involvement in this now. I already have some projects going on and although this one would be very interesting for me to pursue the night brought some clarity - I don't have the time nor focus to take this in now. So I'll pause here and may take it up at a later point in time.

Yet, should someone/some of you be interested in continuing the thread please feel welcome to do so - I'll probably chip in from time to time ...

Have a good day,

Jesper

 

[hollowman]

...for the best ...

I already have some projects going on and although this one would be very interesting for me to pursue the night brought some clarity - I don't have the time nor focus to take this in now. So I'll pause here and may take it up at a later point in time.

Probab. a wise decision.
Soekris already has a product, and I brought up Kickstarter in that thread (= crowdfunded copycats may follow, hopefully better and cheaper). Given the interest Soekris' thread has generated, seems likely Chinese will soon offer similar product on Alibaba/ebay ( hopefully better and cheaper!)