Re: Multiple, sequenced delay lines...can it be done?

[Stan Card <stanitarium@earthlink.net>]

>> ----- Original Message -----
>> From: "Bill Fox" <billfox@fast.net>
>>> The oscillator that clocks the delay line is a VCO.  Modulating the VCO
>> changes
>>> the speed at which samples are stored and retrieved from memory, thus
>> changing
>>> the delay time.  Of couse, anything clocked out of RAM at a different
>> speed than
>>> it was clocked in, will have its pitch changed.
>> 
>> If you use a very short delay and modulate the VCO with a low frequency
>> triangle or sine wave, the resulting effect is what we call chorus.  
>What
>> happens is the delayed material is shifed up and down slightly in pitch 
>and
>> when mixed with the unshifted signal the result is much thicker
>> harmonically.
> 
> yes, its how the legendary PCM 42 and other digital delay lines of
> that time work: The memory is digital but the control of it rather
> analog. You dont have the option to jump arround the memory and treat
> loops like samples, and FB does not go straight up to 1, so the loop
> fades sooner or later, but you gain a more natural way to change loop
> time without glitches and a quality of chorus which is hard to
> achieve digitally.
> 
> (I love to say that while sitting in PCM 24 creator Gary Hall's nice
> little wooden house in Alameda!)


lucky you matthias-i was gonna try to mention something about the PCM42s
ability to voltage control loop length(yeah,i used it @ loopstock), but in 
a
few simple statements you've said what i would have stumbled w/ for a
paragraph or two!!thanx
say hi to <gary hall> for me...
s