The DSP33's cast metal enclosure features threaded hard points on the rear. These were intended to allow for purpose-made wall mounting brackets (Omni-mounts were popular back then) but would also support heavy duty ceiling mounts like the K&M 24496 tilting ceiling mounts and matching K&M 34354 interface adapter plates I've ordered for the ATC SCM12i.

2ch: Jay's Audio CDT2 Mk3, PS DirectStream Dac, Oracle Delphi VI/SME V/Benz LP-S, Coincident Statement Linestage, Foundation Research V5 Phono, JL Audio CR-1 xover
M-ch: OppoMod 203, Anthem AVM60, 2x 557
2x or 5x ATC SCM20ASL mk2, 4x SCM12i, 4x Seaton Submersive HP, AM2.0 sub EQ
Video: JVC X990, Isco 3L A-lens/sled, 105" motorized 2.37:1 AT screen