From gstopp@fibermux.comFri Jun 30 11:46:03 1995
Date: Fri, 30 Jun 95 11:41:59 PST
From: gstopp@fibermux.com
Cc: analogue@hyperreal.com
Subject: Flangers (was Re[2]: Mutron Bi-Phase)


     Lorne Hammond <lhammond@sol.uvic.ca> at ccrelayout wrote:
     
     >Try adding just a hint of white or red noise to whatever you are 
     >putting in. It acts like cigareete smoke in a light beam, makes the 
     >shifting very acoustically visible.
     
     What a cool analogy! Yes I use this trick, on a flanger that I made. 
     Hey - flanger topic - I got frustrated with all flangers because they 
     just can't totally duplicate tape flanging. I'll explain:
     
     Tape flanging (ala Phil Spector) happens when you play the same audio 
     signal on two different machines at the same time, and then lead or 
     lag one playback by speeding up or slowing down the playback speed. 
     The higher the fidelity, the better the flange. This is an effect that 
     Tomita uses a lot - it has the characteristic flanger "sounds like yer 
     in a tube" sound that goes something like this:
     
     ...up-up-up-up-up-up-up-up-< silence >-down-down-down-down-down...
     
     Commercially available flangers go:
     
     ...up-up-up-up-up-up-up-down-down-down-down-down....
     
     which is due to the fact that the silence in a tape flange is the 
     point of total signal cancellation and to do this with a delay-line 
     based flanger (which compares the original undelayed signal to an 
     inverted delayed version of the original) you would have to have the 
     delay line go to zero delay which implies infinite clocking rate which 
     is of course impossible so you never get to the total cancellation 
     point.
     
     So I made a flanger with two 4096-stage CCD's, one of which is fixed 
     and the other which sweeps around the delay of the first. Works great, 
     makes tape-type flanging noises in REAL TIME. The only problem is 
     adding feedback to emphasize the resonant point to make it REALLY 
     "tubular" - maybe I can get some ideas from you similarly warped 
     designers out there. Currently I feedback the final wet mix out with 
     the signal in and it does increase the emphasis, but as you turn it up 
     more then the fixed delay starts to resonate at a fixed tone, which 
     screws up the tubular sweep effect.
     
     BTW using a CD player and an old TEAC R-2-R for experimenting works 
     great - you don't even have to invert one of the sources (anybody know 
     why THIS is?). There are two problems with this method:
     
     1. Getting the damn machines to line up at the same point in the music
        in the first place is a bitch
     
     2. Making the TEAC slow down by putting your thumb on the flat end of
        the capstan HURTS!


______________________________ Reply Separator _________________________________

Author:  Lorne Hammond <lhammond@sol.uvic.ca> at ccrelayout
Date:    6/30/95 11:03
     
Try adding just ahint of white or red noise to whatever youare putting in. 
It acts like cigareete smoke in a light beam, makes the shifting very 
acoustically visible.
     
Lorne