The look ahead feature allows the plug-in to analyze the audio ahead of what is currently being played.

You can use the ‘look ahead’ feature to achieve a better compression.
It allows the compressor to anticipate a transient and compress just before it happens, without lag, to fully control it.
The downsides are that it causes an induced latency, but also a loss of punch and more audible pumping.
The ‘look ahead’ knob has a range going from 0 to -5ms, with an ON/OFF switch on its right to easily turn it off.
It then removes the latency when you don’t want the ‘look ahead’ function to be running.
It allows you to select the side-chain source.

As a reminder, side-chain is the signal used to control the compression applied to the audio.
With the Comp DIODE-609, you can choose between the internal source (i.e., the current audio source/track), and the external source (usually another mix track).
By default, the switch is placed on the internal source.
Switching to external helps when controlling separate instruments (a kick drum and a bass for example), but also when trying to achieve something called “pumping”
Please refer to your DAW manual to check how to route audio to be used as an external side-chain source.
The ‘Input Drive’ knob allows to change the saturation induced by the Comp DIODE-609.

It ranges from 0.00 dB up to +24.0 dB, with 0.00 dB reproducing a similar saturation to the emulated hardware unit, but also being the default value.
Yes, you can.
Simply click on the currently displayed viewmeter to switch to the other type of viewmeter.


Because it is the equalizer dedicated to the side-chain audio circuit.
It further sculpts the audio that will trigger the Compressor circuit (NOT the Limiter circuit)

This only affects the audio that will feed the side-chain circuit, so even if the audio that's going into side-chain is the internal audio, it's output will not be affected by the EQ settings.
To sculpt the sound, you have four knobs: the high pass filter knob, the mid freq knob, the mid gain knob and the high shelf knob.
You may use it when processing the sidechain signal to monitor it, whether it is from an internal or external source.

By pressing the ‘side chain listen’, the side chain signal will be routed to the output, allowing you to listen to the result of the EQing on that signal.
By default, ‘side chain listen’ is OFF.
When it is ON it lights up in red.

You can choose to use the Compressor or the Limiter separately, using the ON/OFF switch on each section.

Using both, the audio will first go through the compressor, and then go through the limiter.