[sdiy] Stereo Phasing With the 32 Stage MultiPhase Project

[René Schmitz]

Hi Scott and all,

Scott Stites wrote:
> It certainly helped getting some of the smaller stage numbers to 
> sound 'tighter'.  In practice, I find as the number of stages 
> increases, I start leaning more heavily in the direction of 'normal' 
> triangles.

On some of your samples there seemed to be an endless train of
notches/peaks coming one after another. Almost like a barberpole.
Thats where 6 stage phasers will fail miserably. Btw, are all those 
stages at the same center frequency or are they offset (or even 
offsetable) against each other?

> That's the million dollar question =-D.  I've been scratching on 
> paper and scratching my head recently on this aspect of the thing. 
> It's either going to be one huge phase shifter or I'll have to start 
> trimming some things out.  As usual, the hardest part is to decide 
> what can fit on the front panel. I'm hoping I can fit nearly 
> everything on a 4U rack panel.  I know that's pretty big for a phase 
> shifter, but this is something I can see using a lot (not just for 
> phase shifting - the control signals will be useful, too).

Right. They should also be brought out, to be used elsewhere. Or for 
syncing etc...

> The phase and regen stages can be selected with rotary switches, 
> though I have been considering using DGXXX type audio switch IC's 
> with momentary switch selection.  

If you ask me the stylisticly correct way of doing the switching in this 
would be to also use vactrols. As I saw on your images it you have some 
left over. :-)

> The real consumer of panel space will be the control section. Not 
> only do I have the LFO/ExtCV/and EF controls to worry about, but I'm 
> looking at having a set of master controls so that both phase 
> sections can be operated from a single set of controls.  The fact 
> that one would *not* want to invert master center voltage and 
> hypertriangular LFO's while everything else is invertable complicates
>  that a bit.

Isn't that just a matter of whether you sum prior to inversion and or 
hypertriangulation or after that? (Geez, a block diagram would really 
help there.. :-))

Cheers,
  René

-- 
uzs159 at uni-bonn.de
http://www.uni-bonn.de/~uzs159