Recall Allen & Heath Avantis scenes over MIDI

What it does

Allen & Heath's Avantis MIDI TCP/IP protocol article, updated 10 April 2026, applies to firmware V2.0 and later. The mixer takes control on its network port. The payload is MIDI, and the client uses TCP port 51325. Message numbers in the article are hexadecimal.

Avantis uses MIDI running status. When the next message has the same status byte, that byte can be omitted. The article's mute example for inputs 1, 2, and 3 on MIDI channel 12 is 9B 00 7F, 9B 01 7F, 9B 02 7F without running status, and 9B 00 7F, 01 7F, 02 7F with it. Status 9B is note-on on channel 12.

Five MIDI channels select the strip type. The base channel N is set in Utility / Control / MIDI. It cannot be higher than 12, and the default block is channels 12 through 16. Scene recall and MIDI Machine Control use N. Inputs 1 to 96 use channel N and note numbers 00 to 5F. Mono groups 1 to 54 use N+1 and notes 00 to 35. Stereo groups 1 to 27 use N+1 and notes 40 to 5A. Mono auxes 1 to 54 and stereo auxes 1 to 27 use the same note split on N+2. Mono and stereo matrices use it on N+3. Channel N+4 carries mono FX sends 1 to 12 on notes 00 to 0B, stereo FX sends on 10 to 1B, FX returns on 20 to 2B, mains 1 to 3 on 30 to 32, DCA 1 to 16 on 36 to 45, and mute groups 1 to 8 on 46 to 4D. The same offset also lists stereo UFX sends and returns. The article's channel table is the full note map.

Mutes are a note-on followed by a note-off. Mute on sends velocity 7F, then 00. Mute off sends velocity 3F, then 00. On the way in, velocity 00 and note-off are ignored, velocities 01 to 3F mean mute off, and 40 to 7F mean mute on.

Faders are NRPN parameter 17. The article writes the three control changes as BN 63 CH, BN 62 17, BN 06 LV. LV runs from 00 to 7F, which the article maps from negative infinity to +10 dB. Assignment to the main mix is NRPN 18, on for values 40 to 7F and off for 00 to 3F. DCA and mute-group assignment share NRPN 40, with the on and off values in the article's tables.

SysEx messages share the header F0 00 00 1A 50 10 01 00. Aux, FX, and matrix send levels are a SysEx that names the source strip and the destination mix. A channel name is at most eight characters, which is what the strip LCD can show. A name request is the header plus 0N 01 CH F7. The reply is 0N 02 CH plus the ASCII name. A name write uses 0N 03 CH. Colour uses 04 to read and 06 to write, and the colour byte runs from 00 to 07.

Scenes are a bank select and then a program change on the base channel: BN 00 Bank, CN SS. Four banks cover 500 scenes. Bank 00 is scenes 1 to 128, 01 is 129 to 256, 02 is 257 to 384, and 03 is 385 to 500. SS is the scene inside the bank, 00 to 7F. The desk also sends that pair when a scene is recalled from the screen. The article also lists custom messages on MIDI strips and press and release messages on softkeys.

How to set it up

1. Confirm the Avantis is on firmware V2.0 or later. In Utility / Control / MIDI, read the base channel. The default block is 12 to 16, and the base cannot be set above 12.
2. Open a TCP connection to the mixer's network-port address on port 51325. Send MIDI bytes on that socket.
3. For a fader, send NRPN parameter 17 on the MIDI channel for that strip type, with the note number selecting the strip. LV 00 is negative infinity and 7F is +10 dB.
4. For a mute, send note-on with velocity 7F and then note-off to mute, or velocity 3F and then note-off to unmute. A bare note-off does not change the mute. The article says those messages are ignored.
5. To recall a scene, send bank select and then program change on the base channel. Use the article's bank table for scenes 129 to 500. The desk echoes the same pair when someone recalls a scene on the surface.

Source: Avantis MIDI TCP/IP protocol.

FAQ

Which port does an Avantis client open?

TCP 51325 on the mixer's network port, for firmware V2.0 and later. The article describes MIDI messages on that socket.

Will a note-off clear a mute?

The article says velocity 00 and note-off messages are ignored on the way in. Mute off is a note-on with velocity 01 to 3F. The transmit example uses velocity 3F, then a note-off.