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Re: Another interesting r2r dac
Posted: Tue Jun 13, 2017 11:41 pm
by rickmcinnis
I have yet to do anything with mine.
Back to LP only at the moment.
There is a fellow at DIYAudio who said it sounded much better in the PUSH PULL mode and with powering each channel separately which makes good sense.
I will eventually install it.
The boards are no longer on the website but if you contact Mr. Kingwa I am sure he will sell them to you. Very nice fellow.
I look forward to our fearless leader to get interested in them, again. I can think of only tried and true things to do whereas Nigel will come up with something interesting.
Re: Another interesting r2r dac
Posted: Wed Jun 14, 2017 6:54 am
by wyan
Thanks, Rick. It interests me since its power supply is easier to implement. 3.3V and 60ma for two boards in push-pull mode. Very easy to go with batteries. Another thing is that it is not so power hungry as the soekris, since soekris draw a lot of current with its digital part.
So, the diyer at diyaudio reported that it sounded much better, is it better than Soekris or than the single end mode with one board only. Could you link me to the post?
Thanks again.
Re: Another interesting r2r dac
Posted: Wed Jun 14, 2017 11:09 pm
by nige2000
This r2r is too simplistic or crude to be highly resolving
The soekris is too complicated with the fpga
We're probably looking for something inbetween like a non oversampled sign magnitude
There was evident that this r2r had some sq benefit over soekris but has super wimpy output voltage and impedance
My last attempt had some audible shadowing
More experiments are needed
Re: Another interesting r2r dac
Posted: Thu Jun 15, 2017 10:53 pm
by rickmcinnis
Here is the thread:
http://www.diyaudio.com/forums/digital- ... odule.html
AS you will see Ben Mah was comparing to his 1541 DAC.
I guess that onboard clock is responsible for much of the extra current required in the SOEKRIS?
I feel sure Kingwa gets a clock in there somewhere in his implementation of these boards but I have no idea how.
Wish I knew more about how DACs work but at the moment with the phono working very well I have to admit I don't care.
But I will, eventually.
Re: Another interesting r2r dac
Posted: Fri Jun 16, 2017 6:17 pm
by nige2000
i had missed that thread
i see richard suggested some of the background noise could be poor gnding, thats quite likely as its far from good
Re: Another interesting r2r dac
Posted: Sun Jun 18, 2017 8:47 am
by wyan
Thanks, Rick and Nige.
A stand-alone R2R network and shift register might actually be welcomed. I suppose we could use off-board clock and implement a good output stage to try to get great sound quality, if the standalone R2R network is not flawed.
Re: Another interesting r2r dac
Posted: Sun Jun 18, 2017 4:19 pm
by rickmcinnis
That is the hope and the key.
I have no idea how to implement a clock so we will have to wait for Nigel to get interested in this and show us how.
Depending on what you have following all one might need is a good buffer. I think I will be satisfied with the output in push/pull mode.
In phono mode for the moment and that requires time, too, so I will not be doing anything with these boards for a month or so. Unless Nigel posts something interesting ...
Re: Another interesting r2r dac
Posted: Fri Jun 23, 2017 12:31 pm
by nige2000
the 574 chips are clocked from bit clock if i remember correct
that it probably best done by reclocking the clpd clk out signal
anyone have any info on these r2r dacs
http://www.denafrips.com/
this ares starts at 580e delivered
Re: Another interesting r2r dac
Posted: Tue Jun 27, 2017 5:17 am
by wushuliu
This is going to sound crazy but I've been listening to this cheap PCM2704 DAC recently and there's something about it that just sounds f*cking fantastic. I don't know why. I've listened to a LOT of <$500 dacs as well as diy so I know what to expect generally, but this damn thing has something going on. Almost no digititis, sweet, articulate, liquid, relaxed but very good detail. Kind of TDA1543-ish but better?
Downside is it's only 16/44. But I don't care, it sounds so good. Need to suss out what's going on here... Only departure from datasheet really is the additional of a 74 flip flop, but I can't tell if that's just for the spdif conversion part.
https://www.amazon.com/Signstek-Coaxial ... B00FEDHHKE
Re: Another interesting r2r dac
Posted: Tue Jun 27, 2017 10:21 am
by nige2000
wushuliu wrote: ↑Tue Jun 27, 2017 5:17 am
This is going to sound crazy but I've been listening to this cheap PCM2704 DAC recently and there's something about it that just sounds f*cking fantastic. I don't know why. I've listened to a LOT of <$500 dacs as well as diy so I know what to expect generally, but this damn thing has something going on. Almost no digititis, sweet, articulate, liquid, relaxed but very good detail. Kind of TDA1543-ish but better?
Downside is it's only 16/44. But I don't care, it sounds so good. Need to suss out what's going on here... Only departure from datasheet really is the additional of a 74 flip flop, but I can't tell if that's just for the spdif conversion part.
https://www.amazon.com/Signstek-Coaxial ... B00FEDHHKE
Although I'm pretty sure you're away with the fairies I ordered one for fun