I just received the Custom Mod Umbilical cord. I haven't done an extensive comparison to the original, plus new one is not broken in. My initial impression that the sound is overall richer, but a bit unfocused. Perhaps more break-in needs to happen. I put some aluminum Symposium blocks under the power supply and the sound became more focused.
Some other things I have experimented with that have had a positive influence on the CD player is having it on a Symposium Ultra shelf with roller blocks and one Stein Music E-Pad stuck on the tray. If I hadn't tried it, I wouldn't of believed the difference the E-Pad makes. I keep on removing it to see if it is my imagination and still has a positive effect, and it always does. I have a few extra if anyone is interested in borrowing one. Oh and currently using a Kaplan cable for the power supply and stock cable for the transport.
The combination of all these things has given me a clean, but warm and musical sound. One test that I always do for sound-stage, clarity and warmth is play the Beatles Love album. On the first track, about a 1:10 into it their is a fly that should sound like it is buzzing across the room. First time I heard it with clarity is after I put direct lines in. I was actually shocked it was their.
Thanks Dan for continuing to improve your products at a reasonable price point.