The ComboBox plug-in was added in Unify v1.2.0. Unlike all the other plug-ins bundled with Unify, it neither produces or processes either sound or MIDI by itself, but instead provides an environment in which you can connect any number of plug-in instances in arbitrary ways, and thus escape the constraints of Unify's linear-chain layer architecture. It's also unique in that you can use a ComboBox instance in any of Unify's three types of plug-in slots: Instrument, MIDI-effect, and Audio-effect. (MIDI Monitor is the only other plug-in which can sensibly be used in all three slot types.)
The image above shows a fairly simple ComboBox patch, taken from the first INST layer of the “Arrival - 0 - Welcome to Unify!” patch in the Unify Standard Library.
In this particular graph, the input MIDI stream is sent to the MIDI inputs of the Audio File Player and Guru Sampler. Each of those nodes has two audio outputs, representing the Left and Right stereo channels. One of the most important things about ComboBox is that it allows you to connect each plug-in's Left and Right outputs (or inputs) individually, and make multiple connections to a single pin (as is the case with the MIDI input here). Contrast this with Unify's layers, where plug-ins are always connected in daisy-chain fashion, and all audio connections are stereo.
The ability to connect Left and Right pins in different ways is absolutely critical for the mda Vocoder, whose Left input takes the Modulator signal and the Right takes the Carrier signal. The vocoder impresses the dynamic tone of the Modulator (in this case a short vocal sample played by an Audio File Player) onto the Carrier (in this case, musical notes/chords played by a Guru Sampler using a synthesized pad sound). The mda Vocoder is actually a mono effect, so its Left and Right outputs are exactly the same.
When the state of a ComboBox is saved within a Unify patch, the state-data includes
This information is sufficient for Unify to completely restore the ComboBox instance to the state it was in when the patch was saved.
When you first load an instance of ComboBox, it will look like this:
Unify's layer system provides another way to combine and connect multiple plug-ins, so what does ComboBox offer that Layers do not (or vice versa)?
ComboBox exposes all parameters of all embedded plug-in instances for linking to Unify's Macro Knobs. The link paths are constructed in a simple way, best illustrated with an example. Using the mono vocoder graph shown in the first image above, you could select, say, the Hi Thru parameter of the mda Vocoder 1 plug-in like this:
The resulting parameter path would look like this:
Note: If you delete plug-in nodes from a ComboBox graph, any parameter links to that node will become invalid (they will display in red instead of green).