VCO or VCF

[Tony Allgood]

Reading some of the notes in the archive, it seems to me that some people
think that its the VCF that determines the overall sound of the instrument.
Do the oscillators actually make a difference? One person said a squarewave
is a squarewave whatever the VCO design. Surely, this is not true. Slew
rate and HF performance of the semis will have an effect, won't they? And
sawtooth outputs, well, some sawtooths can have terrible flyback times. For
instance, my old Rogue (which I sold for 40 UKP about 5 years ago, what a
plonker! ), had a sawtooth with a flat top, like it had been clipped at
12volts.

And what about VCAs, all my modular stuff uses LM13600 or 3080s, does a
AD633 really make a difference that can be heard? Or does it only make a
difference when you try to modulate with AF rather than slow EG outputs?

I will agree that VCF types really make a difference, but for my next
project, I'm going to be working on oscillator waveforms. I am going to use
a 3340 running at a very high frequency driving a Walsh generator bank. I
tried ages back but I tried to be clever and use a digital EG circuit I had
designed for each of its 32 outputs. This time I'll use a bank of pots.
Anyone out there tried using hardwired digital chips to make analogue
waves? I will keep you posted of any positive results.

TTFN

Tony

PS anyone got the circuit schematics for the powertran vocoder or the FAT
procoder?