Post

If I add another VCO I need also another filter and VCA for it or I can let it work with Mother 32?

possibly not sure on patching as I don't have any semis - but more vcas (get a quad cascading one - think of it as an investment (& it can also be used as a vc mixer) - and filters are almost always a good idea

I already have the Wavetable VCO and I'm patching it with Mother 32 but I do not have so many IN and OUT more (I ordered ad multiplier in the meantime...) and I'm triyng to understand how to add another VCO voice

probably using a mixer pre-cv out of moog mixed with vco out, mixer out into vca in of moog??

I also need a Mixer?(Math can be used for this...so probably I'm already ok for that).

whilst Maths does include a mixer, using it as such kind of stops you using Maths for anything insteresting... get a quad (or triple) cascacading vca

so...the real question is:
for any VCO I have in the system is required a filter, LFO and VCA in order to use it?

well not required as such - depends what you are hoping to do... but lots of people have multiples of these per voice... multiple filters can give choice... multiple lfos (and/or envelope generators and/or function generators ie modulation sources) will allow you to modulate more parameters on modules... vcas are useful for both audio and modulation sources... a matrix mixer is incredibly useful for mixing modulation sources together to create more complex ones - especially when patched into vcas and sample and hold modules...