[sdiy] DIY Polysynths

[Oakley Sound]

I did one, I started it in 1984 I think and it took me four years to 
complete it. I used to gig with it live too. Two tolex and wood clad 
aluminium framed boxes, one with the 61 note keyboard, the other with 
the eight voice electronics. The voice cards were mostly CEM based with 
SVF filters like the OB-X. The voice architecture was fairly based on 
the OB-Xa for the most part. The design of the polyphonic allocation 
circuitry was nicked from the ETI Transcendent Polysynth although I used 
a 16bit DAC and several other changes too. There were no memories, no 
autotune and it had five LFOs. And no legending either, although I did 
use colour coded knobs.

In 1995 I broke it up to make two monosynths, and one four voice 
polyphonic synth. The monophonics have long gone now, robbed for CEMs 
and other parts, but the four voice poly still resides in my shed 
unloved and generally waiting for a bit of TLC. It also has been robbed 
of all its CEMs.

I found the old polyphonic note controller board the other day. The PCB 
used power and gnd only while all the signal lines were done with 
verospeed wire and combs. All glued together with conformal coating. Not 
an mpu in sight.

Tony

www.oakleysound.com