ampOSC

Your console, as an OSC server.

ampOSC connects to an Allen & Heath console over MIDI on TCP and republishes every parameter it exposes as BroadwayOSC — the same open protocol Version T speaks. QLab, Companion, TouchOSC or a script of your own can read a value, set it, or subscribe and be told when it changes.

Coming to the Mac App Store — free

What it is for

Consoles speak MIDI, and they speak it in different dialects depending on which one you have. Show control software speaks OSC. ampOSC sits between the two so you write one address, not a protocol implementation — and because the namespace is BroadwayOSC, a cue stack written against Version T addresses an Allen & Heath desk unchanged.

It runs in the menu bar with no dock icon, holds no account, sends nothing off your network, and needs no extra hardware.

One address, whichever desk is in the room

Channels are named and numbered from one, and an index can be a single channel, a range, a list or a wildcard — so one message can address 576 crosspoints.

/Input/3/Level ,f -6.0        set input 3 to -6 dB
/Input/3/Pan   ,f -100.0      hard left
/Input/*/Level                get every input fader, and subscribe
/Input/1-8/Mute ,T            mute inputs 1 to 8
/Scene/Recall ,i 42           recall scene 42
/Unsubscribe/*                let go of everything

A path sent with no value is a question, and asking also subscribes you — which is the shortest way to get a client in sync and keep it there. A switch turns that off in favour of flood mode, where every client is simply sent every change. Which to use.

Every value is in engineering units. A level is dB — −90 to +10, unity at 0, −90 fully off — a pan is −100 to +100, a frequency is hertz. Never a 0-to-1 float, because each console encodes a fader differently: one packs the range into a single byte, another sends a coarse and fine pair under one of two selectable laws. A normalised number would land at a different level on each desk. The conversion happens inside ampOSC, at the wire; a client never sees a raw console value.

The protocol is published. Address format, message intent, the whole namespace, value types and engineering-unit ranges are in the BroadwayOSC specification — v1.1.0, and the same document Version T is built to. Download PDF · Download Markdown.

Six consoles, two ways of addressing them

They do not share one protocol. dLive and Avantis address a channel as a MIDI channel plus a note; SQ, SQ+, Qu and CQ use NRPN parameter numbers. They differ again in ports, in fader resolution, and in what the console will expose at all. ampOSC normalises what it can and is honest about the rest — the OSC surface is identical on all six, and what varies is which parameters exist.

dLive: The fullest of them. Everything below, plus preamp, four-band EQ and high-pass filter, over an encrypted, authenticated socket.
Avantis: The full desk, but it answers a request for names and colours only — everything else has to be tracked from the moment it connects.
SQbeta: Levels, mutes, sends, routing, pan and balance, scenes and cues, strips and SoftKeys. Three matrix.
SQ+beta: Everything the SQ has, with six matrix and the four RackUltra FX units on top.
Qubeta: Twelve mix buses, three matrix and eight DCAs, with MIDI Show Control for cue lists.
CQbeta: The smallest of them. No groups and no matrix, and nothing to assign — levels, mutes, pan, scenes and soft keys.

Beta means those MIDI paths are newly wired and not yet verified against hardware — built from the published protocol documents, but not yet proved on a desk. What that means for you.

Two limits worth knowing, both the consoles' and not the app's. Nothing meters — no published protocol reports audio level over the MIDI link, so no OSC client can draw a meter from it. And on SQ, SQ+ and Qu the fader law is a console setting that no message reports: the same decibel value is a different pair of bytes under each law. ampOSC speaks Linear taper, so those desks must be set to Linear taper — there is nothing in the app to change.

Will it do what you need on your desk? The full support table — channel counts and every capability, for all six families, read from Allen & Heath's own protocol documents. See the console support table →

Getting started

Open ampOSC from the menu bar, then the gear on the console row. Type the console's IP address, pick its family, and match the MIDI channel base set on the desk.
Watch the Inventory count climb. It settles at however many channels your desk is actually configured for.
Point your OSC client at the address on the OSC Server row — port 8765 over UDP, or find it by Bonjour as ampOSC.
Send /Input/1/Level ,f -6.0 and input 1 goes to −6 dB.

The manual covers each of those properly, including the fader law on SQ, SQ+ and Qu — the one setting that will let faders move and still land wrong.

Allen & Heath, dLive, Avantis, SQ, SQ+, Qu and CQ are trademarks of Allen & Heath Limited. ampOSC is not affiliated with or endorsed by them.