it's a VCA compressor that works slightly differently than most standard comps, and here's how:
*the input threshold works just like a Urei/Universal Audio - it's a level control that controls the input signal to the compression amplifier.
*the attack and release times are program dependent. it's like having the unit in 'auto', but having it be adjustable within the 'auto' setting. my DBX 165a's and my Symetrix work awesome in auto, but they each have their thing about it.
with the Orban, it's a peak limiter and compressor with the attack under 3, and gets to be a slow beast at higher settings.
*there's a switch to change the shape of the release curve to linear to exponential (curved, log release). it's like the inverse of knee!
*the 'gate' isn't an input gate, like we're all used to thinking. it's a compressor release 'hold' to prevent pumping of hiss. so, say, if you're doing vocals, and it's averaging a good 5db of gain reduction - get the gate to trigger after the passages are done, and it 'holds' the background noise from raising by holding the compressor at the selected amount of gain reduction (which you set by the idle gain control for however much that is).
*the output trim controls the amount of drive to the VCA compression amplifier. it's not an output control, per se, but it's a post-attack and release amp way to reduce (or increase!) amplifier drive. by riding both the input attenuator and he output trim, I’ve gotten a clean clear compression and a strained, 'in the red' compression, all determined by how hard I’m 'driving' the VCA compression amplifier.
*transformers in and out. it's got a nice little low end gel that's noticeable when you run mixes or especially guitars through it.
*i use the hardware de-essers in this for vocals all the time. you can engage the compressors and de-essers independently, and it's just SO SMOOTH, going from a gentle tap to a cymbal flattening ocean of velvet.
*dual mono or stereo linkable.
so, think of it this way.
it's an adjustable program dependent, transformer loaded compressor you can operate in a clean or driven chip mode with a buttery de-esser and adjustable attack and release curves that's stereo linkable.