Doepfer

HI LIST,
some info on the subject from dieter:

bakis:  "do you think that it would make sense to make a new poll 
about a comb. filter module??or it is similar to the phase shifter 
module??"

 
dieter doepfer:  "There exists not only one "comb filter" module 
type. A comb filter may be realized with phase shifters (i.e. phase 
shift) or delay units (i.e. time shift) or even with several notch 
filters in series. The main difference is the spacing between 
the "holes" of the combs on the frequency axis. The effect resulting 
from phase shifting is called phasing, the effect resulting from time 
shifting is called flanging (earlier made with two tape recoders by 
alternately slowing down the reels or flanges with the fingers). The 
most versatile is the last solution with separate notch filter that 
may be controlled by different CV sources (e.g. independent LFOs or 
Shepard CVs or random or or or ...). In addition feedback can be used 
(like filter feedback). Somewhere I have details of the difference 
between phasing and flanging (pictures of the frequency distribution 
of the "holes", as far as I remember the holes are equal spaced for 
the flanger and logarithmic for the phaser). But as I'm very busy for 
the fair I don't have the time to search the documents. Maybe someone 
of the newsgroup knows detailes too (Florian ?). As far as I remember 
it was in an issue of the Polyphony magazine (about 1983/84). By the 
way a very interesting magazine for technical details of modular 
synthesizers but they stopped it middle of the eighties. Maybe 
someone has scanned the magazine."

...so...anyone??florian??

synthfreak
athens-greece
[doepfer_a100] group moderator