MOTM

At 1:33 PM -0800 2002/02/26, VCOVCAVCF wrote:
>How do you go about creating a Super Saw(tooth) wave
>as found on the Roland JP-8000/JP-8080 on the MOTM (or
>any analog modular for that matter)?  This appears to
>be 7 detuned sawtooth waves.  How are these 7 related?
>  Do I need to use 7 VCOs to achieve this?  Is Roland
>using a static wave to do this or is the relationship
>between the indiviual sawtooth waves varying over
>time?

I can think of two ways to do this with analogue gear:

1. use 7 VCOs
2. use fewer than 7 VCOs, sum them, and put them through a delay line

Digital gear cheats by generating a waveform that sounds like 
numerous saws detuned, and can do this with very little computational 
overheard. A saw wave is just a counter that goes up and then wraps 
around to zero. Detuned saws are similated by partially resetting the 
counter before the counter wraps. By changing the reset point on each 
cycle, it sounds like detuning. If the wave is partially reset N 
times each cycle, it sounds like N+1 detuned saws.

There must be some other way of getting something close to this with 
analogue gear. If an oscillator had a hard sync input that didn't 
completely drain the cap then the detuned saw wave could be created 
with an appropriate hard sync signal. But generating the hard sync 
signal would require 6 detuned pulse waves, so you're back to 7 
oscillators again.