Sounds cool! I also think attentuators are a must for the big version. In case you build the big version I would buy a unit even for a higher price. If the gain parameter is something like resonance it might also be interesting to "break" up the resonance path to be able to use external sound processing modules like vcas or phasers in it. Doepfers Extreme Filter has this option and i think every filter should have that.
Thank you! I agree about the attenuators. Today, I went to a Synthesizer Meeting and finally had a chance to put the PB in a modular system (I don't have any synths). Now I understand why CV-attenuators are important! I think it needs an additional input attenuator as well - I had to run the source signal into a mixer first to attenuate it enough that the PB would not oscillate
The "resonance insert" feature looks very interesting, I'll look deeper into that, thanks!