Open Pre Control

Open Pre Control (OPC) is a universal control software for remote-controllable microphone preamps. Different microphone preamps use different protocols for control and operation, even though audio may be transmitted through a standardised protocol. OPC handles translating these, so they all speak the same langauge, and also handles exposing different interfaces to the user, to operate all of their preamps from a single place without the need for proprietary apps.

The software works in three sections.

  • A protocol-agnostic daemon. This runs constantly, and handles passing messages between device drivers and interfaces.
  • The drivers. These handle taking messages from the daemon, and converting them into what the device understands, and vice versa. Each device has it’s own driver, and these can be loaded in and out of the daemon easily.
  • The interfaces. These are the control surfaces that are exposed to the user, or other software. Like drivers, interfaces can be swapped in and out depending on the use cases. Need to operate your preamps from anywhere in the facility? Load the WebUI interface and access it from an iPad on the same network. Recording in Pro Tools and want to use it’s built-in mic pre controls? Load the Pro Tools MIDI bridge, and let the daemon / drivers convert it to whatever hardware you’ve got. Building a custom interface in TouchOSC, OSC/Pilot or Lemur? Use the OSC bridge to access your preamp controls.

Supported Devices / Interfaces

Currently, OPC supports the following devices:

  • Neumann MT48
  • Focusrite Red16Line
  • Tascam MM-2D-X
  • Behringer XAir 18 More device support is planned - these are just what I’ve got access to! In theory, other Focusrite RedNet devices will work (MP8R, RedNet4, Red8pre, etc.), as they operate over the same protocols. I’d also imagine Merging Anubis will work, as they’re functionally identical to the MT48

And the following interfaces:

  • WebUI (proof of concept - works, but needs to be refined)
  • Pro Tools
  • OSC (proof of concept - not well tested)

I’ll be refining some of this and uploading it to GitHub in the next few weeks, I’m finding it really useful, so hopefully others will too!