[sdiy] Electronic organs revisted: using organ manuals and pedals for synth DIY projects, etc

[Tom Wiltshire]

On 18 Sep 2011, at 02:16, aankrom wrote:

> What I am curious about is anyone else who has done this sort of thing. The keys and the action on the manuals are actually pretty good. I'm just not sure which keyboard scanner circuit is the best to use I'm going to check MFOS and CGS. For the pedal board I'll probably use Ken Stone's circuit that uses a 74C922: I have a a 74C923 which I hope is easily adaptable. I also have an old Popular Electronics magazine from 1979 that shows how to expand key-count of 74C922's using a few 74LS367's, which I happen to have a ton of. (I just do. Heck, it's crazy that I just happen to have 2 74C923's just sitting in my parts bin.) With the 74C923 I should be able to have a 20-note keyboard. Or maybe I could just not use on of the pins and use it like a 74C922.

I built a set of MIDI bass pedals using the 13-note set from a hideous 1970's transistor Hammond. For that I used a key scanning circuit based on a PIC 16F767, which generated the MIDI output too - a one-chip solution.

I've got the keyboards too, and was always intending to build a programmable monosynth with one of them, but in reality if you've designed a programmable monosynth, you might as well add more voice boards and build a polysynth (Ahem! Moog! Are you listening?!!).

T.