The ACP88 comprises eight channels of compression, brick wall limiting and seamless noise gating for a variety of applications. Each channel of the unit contains an audio compressor, which can also be setup as a limiter by varying the ratio of compression. The user has control over threshold, ratio, attack and release for each processor, in addition to selecting between auto or manual attack and release curves, and hard or soft knee compression types.
Additionally each channel of the ACP-88 has a separate dynamic noise gate, that can be used to gate an entire drum kit, clean up a noisy tape machine, isolate an instrument or separate a vocal from background noise. Each noise gate provides control over attack, threshold, release and gate close range. The gate close range can be useful in creating a more natural sounding blend or mix when gating many instruments at once.
Using the Link function allows the user to combine any combination of ACP-88 channels, effectively forming a sub-group. When linked, all processors follow the setting of the master processor, which is always the processor furthest to the left in a link group. For example, one could link together channels 7 and 8 to form a stereo pair, channels 3, 4 and 5 to form a subgroup of processors, while leaving channels 1, 2 and 6 available for independent applications such as compression, limiting, or gating as the situation dictates. In addition, every channel has separate bypass and gain controls.
A compressor sidechain jack is available on every channel. When multiple channels are linked together, the send of the master channel sidechain jack contains a mix of all the channels in the link, which allows control over multiple channels of processing with one sidechain send/return.