Andy,
I have been playing around with the I/V conversion, I have tried AD825, It was a pain soldering them onto the board because they are smd's, it didn't sound bad but the sound became too warm, I also tried AD811,I don't think they are gainstable, I probably need to change some of the circuit to use these, maybe the AD825 would sound better aswell, the other op-amps I have that I can think of are LT1028,Lm6171,LM6181,OPA627,OPA637,OPA604,AD8065,AD8610,AD797
I was thinking about trying just a small resistor from the output of the dac to ground and using 2sc369's, I'm not sure, I did try the discrete circuit that TNT audio use for their diy dac but it didn't sound very good, any idea's would be much appreciated, I also realise the regulators could be improved,( once the output stage is sorted) would your super regs be ok?the Audiocom ones seem good and small but cost a fortune, there is so much to tweak in these cdp's it's knowing when to stop
Ron