I have 2 of these Revelation Audio CryoSilver™ Reference DualConduit™ DB-25 umbilical power cables in the 1 meter lengths. List price for these is $799 for the .75 meter and $949 for the 1.0 meter. The .75 meter is okay if you have the preamp chassis stacked one on the other but if they're even one shelf apart you really want at least 1 meter.

Power umbilical cable for use between outboard power supply chassis and transport chassis of Resolution Audio Opus 21, Pass Labs preamps, McIntosh and others using the DB-25 style connector. Features DualConduit™ design, augmenting isolation and separation of the the crucial analog power supply voltages in a dedicated separate discreet conduit from the digital control signals within the cable. Features Mil. Spec. Amphenol male-to-female DB-25 connectors and solid cast metal shielded shells. The umbilical cable upgrade far surpasses the performance enhancement of a complete component replacement.
These two cables were in use on my XP-30 right up until I replaced it with the XS Pre. They really do make a significant difference IMO. I'm still using one with my XVR-1 crossover.
Price is $450 each including PayPal and shipping to CONUS.
Power umbilical cable for use between outboard power supply chassis and transport chassis of Resolution Audio Opus 21, Pass Labs preamps, McIntosh and others using the DB-25 style connector. Features DualConduit™ design, augmenting isolation and separation of the the crucial analog power supply voltages in a dedicated separate discreet conduit from the digital control signals within the cable. Features Mil. Spec. Amphenol male-to-female DB-25 connectors and solid cast metal shielded shells. The umbilical cable upgrade far surpasses the performance enhancement of a complete component replacement.
These two cables were in use on my XP-30 right up until I replaced it with the XS Pre. They really do make a significant difference IMO. I'm still using one with my XVR-1 crossover.
Price is $450 each including PayPal and shipping to CONUS.