flying high ...

[jorgen.bergfors at idg.se]

What is the effect of adding AP-stages in reality? Do six stages sound clearly 
better than four or is the difference decreasing with increasing number of 
stages? Is there some effect that is only possible with many stages?

/Jorgen





MIME:jhaible at metronet.de on 98-10-09 04.03.24
To:  jhusted at halcyon.com @ SMTP 
cc:  synth-diy at mailhost.bpa.nl @ SMTP  (bcc: Jorgen Bergfors/IDGSE)
Subject: Re: flying high ... 


> The company I work for (Symetrix) used to make a unit we called the 
Phase
> Filter that used 2 ssm2040's in an All Pass config. The thing that 
made
it
> sound great was the control voltage setup. The two filter chips were 
run
> from the same cv but they were never calibrated to track together and 
the
> result was a very deep and fluid sounding phaser. We originally 
designed
it
> with 3 ssm2040's but in that config the thing was WAY too intense (it
bent
> notes and stuff). Having multiple filter banks that don't perfectly 
track
> together makes a huge difference in the sound of phasers.
> -James

This sounds very reasonable. Thought of this, too, but strange enough,
never
really tried it. Some Phasers just use one all pass filter and add /
substract for
left and right. The ARP Quadra Phaser does this, and it sounds ... well,
impressive,
but slightly exaggerated. (I use it Mono most of the time). It's also
common
in chorus devices. Another way to go stereo is using two separate delay
lines
(or all pass filters) and modulating them in the opposite direction. 
Many
"true
stereo" chorus devices do this, like the chorus FX in Juno 6, MKS 30, 
and
so on.
I have once designed a Phaser for Braintec (It was part of the "Trancer"
that never
made it to the market) which could be configured as either 12-stage 
mono or
6-stage stereo, but again: opposite direction of modulation.

Now what you describe is very interesting. I'm sure it *must* sound 
good !
If this whole HiFli stuff works, I'll definintely try this 
configuration,
too.

As for phasers being too intense and bending notes, I don't really think
it's a function
of the number of stages. There's just a modulation amount above which 
even
a short
phaser sounds detuned, different wet/dry mix has some influence too, 
but I
can
confirm that even a 14-stage phaser can sound like a phasing sweep 
without 
a dominant detuning effect. (ARP Phaser)

JH.