Another Discrete R2R Multibit Dac that can do DSD, again from the land of the Great Wall

George,
It's time for you to come up with a R2R DAC of your own design. Kill them all!

Digital is a totally different animal to analog, like Ying and Yang. I've got no problems with I/V and output stages in dacs and cdp's. But the 0 and 1's side of things leave me cold.
Cheers George 

George I'm curious, what would be your preferred method of I/V  and output stage circuit if you were to design a DAC?
Charles,

An I/V passive resistor is very tempting, but the trouble is it knocks down the output of the dac so much the amplification after it has to be huge and that means so is the noise. I/V transformers sound too colored to me. Both of these suffer in the dynamic department.

I prefer this I/V stage thread I started, zero feedback and very high slew rate I/V, 3 -4 stacked, so the input impedance comes down to around 10ohms, and the current handling goes up, so there’s no current limiting as happens with a single one.

http://www.diyaudio.com/forums/digital-source/227677-using-ad844-i-v.html
(go to page 17 mid way down) that’s where it starts getting interesting with the stacking of these I/V stages.

As far as the buffer, good clean low output impedance with good current output, discrete or opamp based I’ve used both on this thread and reported their sounds with this I/V stage.

At the moment I also have a Linn CD12 v2 here, which uses similar I/V but with 4 X PCM1704’s and it is very good on PCM 16/44 and 24/96 replay.

Cheers George