Kawai MIDI PATCHBAY MAV-8 is powered and highly recommended. Less than $120. used…or used to be. It’s powered, rack mounted, 4 MIDI IN x 8 MIDI OUTS with one of each on front panel. This is not USB, just straight MIDI DIN and works a charm. Has 8 sliders on the front so you can control easily at all times what’s going where.