Phasers

[James Husted]

We used to make a unit called the Phase Filter(here at Symetrix). It was
based on 2 SSM2040 filters arranged as an all-pass filter (phaser) array
like in thier datasheet (with some mods of course). There is a socket for a
third filter, but the effect is almost un-controllable if installed (we
stoped putting them in when they went  into production. It has 2 lfos (one
swichable to manual[DC]) and mix control and a control voltage input.
Bypass footswitch. Low and line level inputs.  I'm sure you have never seen
one of these (we stopped making them on the mid 70's) but the are very cool
and make a interesting sound. The filter chips don't track together
perfectly so the notches produced move closer and farther apart as well as
up and down. This makes for a very `organic' (for want of a better term).
If you add the third chip (which is worth a look see) it's so intense it
bends notes. I'll look around and see if I can dig up/scan the schemo. In
any case, if you take the design off the ssm2040 spec sheet and double it
(or triple it), and can get the chips (I have a few I can sell you) you'll
get a great Phaser that can be switchable into a LP Filter (4 poles per
chip),with resonance and voltage control .
>What is the ultimate analogue phaser design?
>
>I am working on a signal processing modular set up
>(that I mentioned a couple of days ago), and the main
>module i am interested in is a dual phaser. Anyone
>have any designs?
>
>bud


James Husted
Art Director, Web Master, Symetrix Inc/Lucid Technology
jhusted at symetrixaudio.com
jhusted at lucidtechnology.com
jhusted at halcyon.com