What equipment do you most regret parting with??

Apt Holman preamp and Apt 1 amp, would have made a great second system.

KEF RDM 2, one of my favorite speakers regardless of size or price. Would have sounded good with above components in a second system. I have been looking for a mint used pair ever since.

Pioneer PD 65 CD player, great player that I traded in for a P.O.S. transport.

There are many more but those popped into my head first.

Parasound A-21

Marantz 7c, pair of MAC 240s and Chartwell LS3/5as

Infinity Reference standard 1 (thought I might be able to make small speakers sound as good, Wadia 860.... looked and finally replaced it thought it was depreciating but 8 years later they go for same price I sold it for originally, Matched pair of Entec Sw-1 (the only sub that ever sounded musical,

Yamaha CR 1040 receiver. Sound, build and looks, it had it all. Had long moved on, giving it to my sister. But is was so nice I have come to regret it. I could have easily used it in a secondary system.