opinions needed

[WeAreAs1 at aol.com]

Gino Wong <adaaxs at erols.com> wrote:

<< One idea that I have been
thinking of is that of the EML synths, which are nice but lab equipment.
 They have an LP / BP /  HP module that is implemented on one sweeping
mode pot.  Pan right through three modes. >>

Yes, that's one the coolest features of the EML101.  The way that filter mode 
pot is implemented is quite different from the filter mode pot on the 
Oberheim SEM.  The EML pot is a linear pot that has a center tap.   The 
outputs of the three filter responses are attached to the center tap 
(bandpass) and the two endpoints of the pot (lowpass and highpass).  The 
wiper can then just directly pan between these three filter outputs.  This 
gives the mode pot a more dramatic effect than the sound you get when you 
sweep the mode pot on the SEM.  

It would also allow you to change the order or position of the three 
responses, relative to the pot knob.  That is to say, if you rewired the 
three taps, instead of having it sweep from Lowpass to Bandpass to Highpass, 
you could have it sweep from Lowpass to Highpass to Bandpass, or even to the 
output of a completely different fiter.  (I guess you install some patch 
points to acheive this, if you found it useful) 

The real trick, for us DIY'ers, is finding a source for rotary pots that have 
a center tap.   Does anybody out there have any sources for these?  I'd sure 
like to get some.  Center tapped pots with a center detent would also be very 
useful, especially for things like CV attenuators with both positive and 
negative CV outputs.  Having a grounded center point with a detent would 
ensure that it would always be easy to find the "off" point in the attenuator 
knob's travel.

Michael Bacich