Check the listing for details. Opcode Systems Studio 4 Midi Interface. Condition: Used, Made in United States. Listed at 29.95 USD. This OMS Studio 4 is a MIDI interface designed by Opcode Systems Inc. It is a United States made professional-grade tool for musicians and producers looking to connect their musical instruments and gear to a digital audio workstation (DAW). With its reliable brand name and specific focus on MIDI functionality, the OMS Studio 4 offers a high-quality solution for capturing and manipulating musical data in real-time. Whether for live performances or studio recording sessions, this one space rack mountable interface provides seamless integration and control over your musical creations. The 9Volt DC, 1.5 Amp, positive pin, negative sleeve power adapter is not included.