Wasps, DCOs, OSCs and Bill Clintons pants?

[Magnus Danielson]

>>>>> "PP" == Paul Perry <pfperry at melbpc.org.au> writes:

 PP> At 06:49 PM 29/10/98 PST, Bjarne Nillson wrote:
 >> Now, how do we change the square wave to a saw!
 >> Easily by a odinary integrator,the same integrator used in a VCO!
 >> 
 >> Now, the discussion starts to be interesting,
 PP> .....because, I am going to ask BJ how to keep the amplitude of
 PP> the saw constant with frequency!

A VCA solution?

Personally I would use a CPU or MCU to act as an phase-accumulator, a
24-bit phase accumulator can track all tones and all cent step pitch
shiftings acheivable over MIDI (that is 128 notes) within +/- 0.025
cent error with a full linear modulation. One will get a sawtooth
waveform which needs a DAC to get into the analogue domain. For those
that reguard this precission being way to large, you are fully free to
add frequency drift, frequency modulation, phase modulation etc in a
very simple manor... but then, this can be done with analog cursuitry
equally simple (except for a few notable exceptions).

I once wrote the core code for a 8051 that where intended to play
samples, it implemented the 24-bit phaseaccumulator and used a divide
down of the clock to execute the phaseaccumulator and sampleplay as a
interrupt sequence. I never got around to do a exponential converter
thought.

Dividers as DCOs is a quite lousy solution.

Magnus
Constantly confused and constantly confusing people