master / slave digital cable for 440Pro

[Confused]

One thing occurs to me reading these posts, I presume most D400 users received the Chrystal cable when originally buying the 400, or maybe when upgrading by buying a companion?  I also presume that D400 owners sent the Chrystal cable back with the amps when they were sent for the 440 Pro upgrade?  If so, is this not just a case of owners getting their old Crystal cable back?  Did anyone send the 400 back without the old Crystal cable but still received one back with the 440 Pro?

I think the OP is getting confused. The amps came back with Audioquest mains cables, not interconnects.

I sent my 400s back with exactly what they wanted, which didn't include interconnects, so I've ended up with two crystals as they sent one back with the upgraded amps. Bloody right too, considering the price. And if you're going to go the whole way: new boxes, manuals, mains cables, gloves and guarantee etc., it would be silly to spoil the ship for a 'haporth of tar, and not supply them!

I am not sure if the OP is all that confused.  For the record, my 1000 Pro came with a very nice Audioquest Carbon cable for the master companion link, and also for the trigger cable. (which is a bit OTT)  This was a new 1000 Pro and my 'part exchange' D800 went back with it's Crystal cable for the new owner to enjoy.   So obtaining a sneaky extra Crystal cable perhaps shows one potential benefit of getting the upgrade rather than part exchanging.  It is also worth noting that the Audioquest Carbon cable supplied for the master companion link is directional, and if you use the inputs on the companion, this cable has to work in the 'wrong' direction.  Oh the utter horror!  Ironically my nice new Audioquest Carbon cable is sat in a box waiting for me to decide where to use it, I am running the Audioprana RCA to AES cable for the master companion link.