deft_bonz wrote: ↑
Tue Jan 05, 2021 11:49 am
If I may ask, what does the Expander add? Note, Out A, Out B, the two FM inputs and again two outputs there. The same for PWM.
And the two VCO inputs (?) in the Processor? I was a little confused because in the VCO the oscillators are labelled VCO and the Processor and Expander show Voice. Curious to know what you have planned.
The Expander basically adds common tune and PW controls that are normalled to the Note A/B and PWM A/B outputs respectively. So you'll be able to control the frequency and PW of every VCO on one or two Poly-8 VCO modules simultaneously (for when there are two VCOs per voice, for example) using one potentiometer.
Common FM and PWM inputs are also provided, that are normalled to the FM and PWM A/B outputs; so that CVs can be sent to up to 16 VCOs if required, from one input. The multiple inputs e.g. FM 1 and 2 are summed and are output via A/B. The same for the PWM inputs. This is useful for sending independent FM/PWM CVs per voice, rather than a common CV or for adding an extra FM or PWM input to each VCO (rather than just having the one built into the module). Two Note outputs per voice are also given. Obviously with requiring precision; the note outputs will be trimmable to obtain exactly 1V/octave.
The Processor module essentially acts as a voicing module i.e. VCF, VCA and mixer combined. The two VCO inputs i.e. VCO 1 and VCO 2 on the Processor are for multiple VCOs per voice. So for example; you could take the ramp wave from a VCO on one Poly-8 VCO module and one from another unit and input them into the VCO 1 and VCO 2 inputs on the Processor to give two VCOs for voice 1 and so on for the other voices.
The Aux inputs are for external sources, such as noise etc. The CV inputs on the Processor are self-explanatory; these are independently per voice. Common filter controls such as frequency, resonance and their related CVs are given, that are internally routed to all voices. The Init Gain knob is a common VCA gain control for all voices for drone etc.
The VCO 1, 2 and Aux In knobs are simply level controls for the Mix Out. So turning VCO 1 all the way down to 0 will mute the VCO 1 channel for all voices. Same for VCO 2 and Aux In. This basically replicates the front panel mixer controls of the Prophet 5.
The reason I didn't label the individual VCOs on the Poly-8 VCO module as "Voice 1" etc. is because people may want to just use this module on its own, as a oscillator bank and not specifically in a polyphonic configuration. Whereas the Expander and Processor modules only really make sense to be used in a polyphonic setup and not on their own. So "Voice" seems more appropriate. Having said that; they could be used on their own.
Hope this makes sense. I think it will all make a lot more sense in practice.