yeah, i've been dreaming of this for about the past year...now i am going to DO this! i have placed orders with jameco, bg micro and effects connection (they have 3pdt "mxr" style switches for $3 each! best price i've seen!).
i am going to start with the VCO and the keyboard. i will be using reed switchable keys i harvested from a lowery organ. so, they keys shall have a nice weight to them. the voltage controlled oscillator will be 555 based. a part of me would like to run a parallell circuit with trimmers from the pitch point of the circuit to the keys, to keep that mono-synth vibe. but, as i have been told multiple times, it would probably not stay in tune. so, i will be using a 74c922 key scanning chip. i do not know, but i have a feeling it will not be mono...sigh. input?
once i get the keyboard going (the case will be built, etc by now), i will start experimenting with the filter and lfo! i will prolly build different versions of filters, but my first lowpass will be based on a butterworth lowpass in an IC! i didn't know there was a chip for this! wow! it sould be easier, i would assume.
there will be an LFO to add modulation to the pitch of the VCO and the cutoff of the VCF. i'll use a patch cable and jacks to connect to the cutoff and the pitch.
also, a point to ponder (as well as a decision which should already be made!) is, how many keys should this have? the keysets have 3 octaves, but i would like to just do one octave, c to c. in order to do this, i'd have to actually CUT the circuit board which the diodes and reed switches are connected to. hack saw?
i will be doing bass pedals as well.
anyhow, your input please.