ampOSC manual

Connecting a console

Open the gear on the console row. There are four things to set, and on dLive and Avantis only three of them matter.

The six families

ampOSC speaks to six Allen & Heath families, and the OSC surface is identical on all of them. What differs is which parameters exist on a given desk, and that is advertised through the inventory rather than being something you configure.

Family	Status	What it is
dLive	Verified	The full desk. Everything the app can do
Avantis	Verified	The full desk, but it will only answer a request for names and colours
SQ	Beta	NRPN mixer. Three matrix
SQ+	Beta	As SQ, with six matrix and the RackUltra FX units
Qu	Beta	NRPN mixer
CQ	Beta	The smallest. No groups or matrix and no assignment — level, mute, pan, scenes and soft keys

Beta means the MIDI paths are newly wired and have not been verified against hardware. They are built from Allen & Heath's published protocol documents and should be right, but nobody has yet plugged into one of those desks and proved it. dLive and Avantis are the proven paths. If you are running a show on a beta desk, test it in the room before you need it — and tell us how it went, which is how they stop being beta.

Everything the console connection needs, in one sheet.

Address and family

The IP address is four separate fields, one per octet, so a typo is harder to make and easier to see. The TCP port is 51325 on every Allen & Heath desk and is not usually worth changing.

Console Family is dLive, Avantis, SQ, SQ+, Qu or CQ. It has to be right: the families encode their parameters differently, and the wrong choice reads valid messages as the wrong ones rather than failing cleanly.

The picker at the top of the sheet holds saved profiles. Custom is the one you type an address into.

Both machines must be on the same network, and the console's MIDI over TCP has to be enabled in its own settings. It is not on by default on every desk, and that is the single most common reason a correct address does not connect.

The MIDI channel base

These consoles spread their parameters across several consecutive MIDI channels, starting from a base you set on the console itself. ampOSC needs the same base, or it will read the right messages as the wrong ones.

Family	Channels used from the base	Desk default
dLive	Five	12
Avantis	Five	12
SQ	Two	1
SQ+	Two	1
Qu	Two	1
CQ	One — fixed at channel 1	1

Set it on the desk first, read it off, and type the same number here. A base that is out by one is the classic symptom of faders moving the wrong channels.

The CQ is the exception: its MIDI channel is fixed at 1 and cannot be changed, so there is nothing to match. Qu uses two — the mixer's own channel, and its DAW control strips automatically one above it.

The fader law — set the desk to Linear

SQ, SQ+ and Qu each have two selectable fader laws, Linear taper and Audio taper, chosen on the desk under Utility › General › MIDI. No message reports which one is active.

ampOSC speaks Linear taper, and there is nothing in the app to change. Set those desks to Linear taper. On Audio taper the faders still move but land at the wrong level, which is worse than not working — and no setting here will correct it.

dLive, Avantis and CQ each have a single fixed law, so there is nothing to choose. CQ's own document mentions two level tables and an NRPN Fader Law setting, but it publishes one table — the audio-taper curve — and has no such setting; those sentences were carried over from the SQ and Qu documents.

UltraFX units

A UFX button sits beside the console gear on desks that have RackUltra FX — eight units on dLive and Avantis, four on SQ+, and none on SQ, Qu or CQ. Each unit gets its own MIDI channel and a model, and the app then exposes that model's parameters as /UFX/{unit}/{Name}.

Channel — the MIDI channel that unit listens on, or Off.
Model — picking one reveals only the parameters it actually exposes.
The CC per parameter. Editable on dLive and Avantis, because those desks let you remap them on the surface. Fixed on SQ+, where the firmware decides.

A UFX channel must sit outside the mixer's own range. The core reserves channels from your base — five on dLive and Avantis, two on the SQ family — and a unit placed inside that range is flagged with a red ✗. It is the same clash as a wrong MIDI base, and it will look like the wrong parameters moving.

The UltraFX sheet: eight numbered unit tabs with unit 1 selected, its MIDI channel, a Model picker set to Vocal Tuner, and the CC number sent for each of that model's parameters — Key, Scale, RetuneSpeed, TransitionTime, Correction and Bypass. — One unit at a time: its channel, its model, and the CC each parameter answers to.

Surface scene controls

dLive only. Its cue-list Go, Next and Previous are user-assigned CC messages rather than a fixed protocol command, so the app has to be told which CC and which value each one uses — they are set on the desk and matched here.

The defaults are CC 1, 2 and 3, each with value 127. These are what /CueList/Go, /CueList/Next and /CueList/Previous send; get them wrong and those three paths do nothing while everything else works.

The other five families have no equivalent. SQ, SQ+ and Qu navigate a cue list through MIDI Show Control instead, which needs no setting up.

What each console will tell you

The families differ most in how much they will answer when asked. This is not something you configure — it is worth knowing because it explains why one desk populates instantly and another fills in as you touch it.

Family	Answers a request for
SQ and SQ+	Anything
dLive	Mute, fader, main assign, send level, group and aux routing, preamp, name, colour, PEQ and HPF
Qu	Mute, level, pan and balance, and routing assignment
CQ	Mute, level, pan and balance
Avantis	Name and colour only

On Avantis, ampOSC therefore tracks state from the moment it connects rather than being able to ask for it. A value it has never seen change is a value it does not know yet — move the control once and it will be right from then on.

If it will not connect

Is MIDI over TCP switched on at the desk?
Is the address right, and can you reach it — does ping answer?
Is the family right? A wrong family can connect and then behave strangely.
Is the MIDI channel base the same on both sides?
Is anything else already holding the console's MIDI TCP connection? Some desks allow only one.

A green dot with an Inventory of zero means the socket opened but nothing useful came back — which is almost always the family or the MIDI base rather than the network.