Selling my Avid Mbox 3 Pro FireWire audio interface. I’m the original owner — purchased new, used in a smoke-free home studio, and always treated gently. Cosmetically excellent with no visible scratches, scuffs, or blemishes. All rubber feet intact, all knobs tight and smooth.

Tested and verified working (April 2026):

∙ All 4 mic preamps with 48V phantom power

∙ Both front panel DI/instrument inputs

∙ Both headphone outputs (A and B)

∙ Main outputs

∙ MIDI in and out

∙ S/PDIF: untested (no gear to verify)

What’s included:

∙ Avid Mbox 3 Pro unit

∙ Power supply with AC cord

∙ Breakout cable (DB-15 to S/PDIF coax, MIDI, Word Clock)

∙ FireWire 800 cable (9-pin to 6-pin)

∙ FireWire 400 cable (6-pin to 6-pin)

∙ Original box

What’s NOT included:

∙ Pro Tools software or license (this is hardware only)

Important compatibility note:

This is a FireWire interface — not USB. Official driver support ended at macOS 10.11 El Capitan. I tested this unit on macOS 10.7 Lion with Pro Tools and it works perfectly. Best suited for users with older Macs or Windows machines with FireWire.

Happy to answer any questions. Ships well-packed in original box.