What RCA cables are those that is connecting your Grace SDAC to the Atom? They look very well made & shielded.
They fit quite snugly on the SDAC, but required some slight bending of the adjustment tabs for the Atom plug end. I flipped them of course to check if was the cable, but it's just the Atom's female RCA are just marginally smaller.
FYI the diff between the A01 and A02 cables - apparently the A01 uses Japanese components (per a thread I found on headFi forum).