Thanks Martin, I'll be interested to hear if you think it makes any change to the sound.
I've ordered a few other types/makes of caps (tant and film) to try out, so I'll post my findings.

I've mostly done the same mods as you although I'm using Murata regs and currently have some Jensen caps for the passive mod (I'm trying lots). I've also swapped the resistor behind the 5V reg for a wire link but I've also swapped the fuse for a wire link. My next mod will be to swap the diode of a hexfred to see if that makes a difference. I'm trying to get the cleanest power possible into the DAC so that I can forget about that side of things and concentrate on tuning the sound with the choice of passive output caps.