Paia 2720-1 VCO and 2720-3L LPF Arrive

Right now I have more panels than space. This is confounded by the fact I've made another trade and that I bought a 2720-3L VCF and 2720-1 VCO for cheap on the E(vil)Bay. I got them both for less tham $45 combined so I figured what the hell and pulled the trigger.

As crazy as it sounds, I'm going to build another cabinet and keep building in this format. I like the real simple 2x4 and 4x4 panels. It works well for my DIY skills and needs. I'll build bigger panels for my "real" DIY modular but I'm going to keep going this direction for a while, especially now that there's other great (and easy) DIY Hz/Oct. projects out there. I actually have quite a few Hz/Oct. instruments and am investigating to see if I can make my MiniKorg 2 a master keyboard.

Something that's real cool about this VCO and VCF (as well as many other early Paia modules) is that they are mostly discrete. The LPF is completely discrete and the VCO only has one or two op-amps. I personally think discrete technology is pretty damn cool and I'll never buy another synth that is reliant on obsolete chips.

The 2720-3L LPF is cool but it needs some modding to be brought up to specs. I'm really looking to play and enjoy this synth (see previous posts) so I'll do any appropriate mods as long as it keeps with the general spirit of the synth. I'm going to replace the paper caps and make this into more of a BPF. I'm also looking at some easy ways to add resonance to it.

Here's a look at the new old modules:
































Here's the schematics. It's shocking how simplistic that LPF is. I like the VCO quite a bit although it's not the most stable beast around..



















Here's an image of the VCO from Brice Ward's book. As you can see it's very similar to the 2700 VCO design.