Bode Barberpole Phaser

[Mike I.]

I've done some initial (emphasis on "initial") experiments with diy 
barberpole phasers. The first used the approach outlined in the Bode 
patents - frequency shifter plus direct/shifted mixer plus additional 
allpass stages. It certainly works, but tends to sound like the same 
"package of notches" is being repeatedly swept up (or down) when the 
additional allpass stages are used. Feeding direct audio into one 
speaker, and feeding slightly freq-shifted audio into the other speaker 
produces a nice spatial effect. The other approach uses a parallel bank 
of bandpass VCF's, or series bank of notch VCF's, with say 4 to 8 
filters being swept by a 4-phase or 8-phase ramp generator. VCA's are 
needed as well to blank out the "retrace" as the filter is suddenly 
swept back to it's initial frequency at the start of each ramp. This 
involves more hardware than the frequency shifter approach (which is 
already complicated). I can send some short MP3's if you are interested. 
I don't know of any recordings which feature the Bode unit. 
Mike