Touch Switches/TS instruments (was: Possibly goofy idea)

[CasioRZ1 at aol.com]

Hi all,

(beware, this is kinda long winded :-)

Allright, I missed the first part of this post, but regarding the PAiA touch 
switches, they work really well.  In fact, I built a whole instrument out of 
'em.  

Basically, I wanted a way to be able to add a live element to my sets (I play 
mostly jungle/drum n' bass and trance type stuff) but I suck at playing 
keyboards.  However, I've been playing guitar a long time, so after countless 
dissapointments with modern guitar synths (Axon, roland, et al), I just 
decided to build my own.  

If you've tried guitar synths, you know that the problem w/tracking comes 
from having the synth try to read and convert the pitch of the string, which 
is gonna take a little time even in the best case scenario.  My solution is 
to ditch the strings... hey, if I wanted guitar type sounds, I'd just play my 
guitar!   

Sooo (inching slowly to the point) I found that PAiA touchswitch schem (thank 
you PAiA!) and I found a keyboard schematic on TomG's site (again, thank you 
TomG).  Initially, I was going to combine the two to be able to send CV by 
hooking the touch switches up to relays that connected to the resistor bridge 
thingy (sorry for my crappy terminology, I know very little about 
electronics).  I hooked the whole thing up, and hey, it worked!  Pressing 
different touch switches would make the resistance across the bridge change.  
  

So, then I was going to build a Mad Mouse to control, but I encountered 
<a href="http://www.geopath.com/~jraden/knobs.html">this guy's project</a>,
which used a basic stamp to read pots and then send midi controller info.  
Since my touchswitch instrument is basically just a gradiated pot anyway, I 
decided I could probably do the same thing except send note info.

And... it works!  Really, really well, in fact.  It "tracks" better than any 
guitar synth I've ever used, but it is limited.  First, it's monophonic 
(which is what I wanted at the time, but I'm working on another one that is 
six note poly). it's not velocity sensitive, and there's no string trigger so 
you can't do pick style triplets (working on that too).  But, there is a cool 
joystick on it that sends filter and cutoff controllers (since your right 
hand isn't doing anything anyway :-)   

Here's a page w/a couple pics.  Yes, my wiring is awful, and it looks pretty 
odd... but it works really well, and hey, it's my first electronics project!
http://members.aol.com/casiorz1/mono.html
<a href="http://members.aol.com/casiorz1/mono.html">yup, here it is</a>

BTW, in my experience, the touchswitches were *much* less reliable on a 
solderless breadboard than when put upon a piece of protoboard.

BTW BTW, qprox.com sells touch switch ICs.  Much less wiring would be 
invloved w/these than the PAiA circuit.  I've ordered some from 'em, but I've 
yet to receive them.  I'll let the list know how they work out.

Thanks for reading!

Derek
casiorz1 at aol.com

In a message dated 5/10/2000 3:29:43 PM Mountain Daylight Time, 
sdcurtin at lucent.com writes:

<< Subj:     RE: Possibly goofy idea...
 Date:  5/10/2000 3:29:43 PM Mountain Daylight Time
 From:  sdcurtin at lucent.com (Curtin, Steven D (Steven))
 Sender:    owner-synth-diy at node12b53.a2000.nl
 To:    chordman at flash.net, synth-diy at node12b53.a2000.nl, uzs159 at uni-bonn.de 
('René Schmitz'), honcho at paia.com ('honcho at paia.com')
 
 I tried the circuits on that page and couldn't get them to work, at least on
 a protoboard.   Maybe I'm too much of a digital guy :).   This is why an
 experimenter's kit with a working circuit board of these things, with the
 pads right on the board, would be a great thing (hint, hint).
 
 Steve C
 
 -----------------------------------------------------------------
 Steven Curtin  
 Lucent Technologies Microelectronics
 ph: (732)949-4404   fax: (732)949-6711
 http://curtin.emf.org
 sdcurtin at lucent.com
 -----------------------------------------------------------------
 
 
 > ----------
 > From:    René Schmitz[SMTP:uzs159 at uni-bonn.de]
 > Sent:    Wednesday, May 10, 2000 4:40 PM
 > To:  chordman at flash.net; synth-diy at node12b53.a2000.nl
 > Subject:     RE: Possibly goofy idea...
 > 
 > At 07:30 10.05.00, Scott Gravenhorst wrote:
 > >Touch switches!  Didn't I read here that a CMOS gate input can
 > >work as a touch switch?  If so, are there biasing requirements?
 > >ESD protection things?  Output conditioning?  Could I make the 
 > >pads by etching a board and coating it with clear lacquer?
 > 
 > Hi Scott!
 > 
 > The relevant link here is: http://www.paia.com/touchsw.htm
 > I haven't tried it, if you do let us all know.
 > 
 > Bye,
 >  René
 > 
 > 
 > transconductance | uzs159 at uni-bonn.de
 > isfutilepreparet | http://www.uni-bonn.de/~uzs159
 > obeassimilated.. | http://members.xoom.com/Rene_Schmitz
 > 
 >>