Conference napalm::commusic_v1

THe ARP is basically a frequency to voltage converter going into their old
single board ODYSEY sythesizer.The ROLAND is probably the same into the later
technology available JX3-P and uses the same add on editor to modify the 
available sounds.I used to work with ARP at the time the AVATAR was released
and I feel frequecey to voltage conversion is dangerous if you want the REAL
guitar sound to be the same pitch as the Electronic creation.The new ROLAND
is at E.U.Wurlitzers in Framingham mass and has a MIDI to connect to most
newer synthesizers (and computers).Go see before you build.It will hwelp or
discourage you effectively.

	Lee...

	The new Roland is also at the Nashua Daddy's. I haven't
heard it, but it sure looks pretty.

						- Karl

Thanks guys.  I have since heard about the roland guitar
synth from someone who is planning on buying a JXP3.  
It seems they're using Digitally controlled ocillators.

Well, it was an educational experience, which is the mail
(oops) main reason I read this file.

For your information, the Roland guitar synth is around $2100,
and the guitar to go with it (wow) is around $1000.  The guitar
has a carbon-fiber neck brace that looks rather radical, to
say the least.

					-Jeff

		You can get a HEX pick-up from 
	an outfit called BARTALINNI (spelling?) in californina
	I've got one already, it took 3 months to get here.
	I'm building a guitar of the sort that your describing
	right now. I'll tell you how it turns out.
	I've also got the guitar waveform-to-VCO problem
	licked..Zero-crossing detector & Phase-locked-loop &
	a VC-function generator.
	the rest is a piece of cake.


						Mr. SQuid
	REAL NODE NAME AND NUMBER:
	BARNUM::JWALTON or KL2263::JWALTON

	More on the HEX pick-up.

	OUTPUT SIGNAL is ~70mv
	with 22 dB of seperation between adjacent strings.
	you can get them in different string spacings if
	your guitar isn't a FENDER.

	address:

		BARTOLINI GUITARS
		P.O. Box 934
		Livermore, CA 94550

	cost:

		135 dollars


	The CEM chips sound like a good idea (saves on board space)
	Do you know a source of any information on them. All I've
	got are the prints to the PAIA PROTEUS.
	By the way, my design goals for this thing include the 
	ability to fit on a standard stage.


						Mr. SQuid

Yes, by all means, send me anything you can about your project.
I'm in the process of moving now, so I have no place to work, but
when I get settled in my new place, I plan to first check out
some experimenter's kits that PAIA sells, each built around one
of the Curtis chips.  They're in the $20-$30 range, and supposedly
come with notes about possible uses.  I'd probably get one 
envelope generator, one VCO, one VCF and one dual VCA.  As I said,
I have very minimal knowlege of analog electronics, but with a few
parts to play with maybe I can learn something.  At the least I
should be able to create a simple one-voice synthesize, minus keyboard
or other controller.  If I reach that point fairly easily, I would
then become very interested in your zero-crossing detection VCO circuit
and anything else you have developed for your guitar-synth project.
If I come up with a prototype one-channel guitar synth, I could
then order another set of chips and see how cheaply and compactly I
could build a one-voice guitar synth module.  The final stage would
be to build five more modules, or more, to complete the system.

more later...

I had another idea.
I'm getting a Schecter strat neck maple (which is uncoated)
What I could do is cut a channel in the back of the neck,
lenghtwise that is. Then cut smaller channels from long channel
out to each fret. Then run small gauge wires down the channels
to the frets. The guitar strings must then be electricly isolated
This would complete a switching array. Could then use a multiplexer
to scan the strings. Then feed a MIDI interface to control key board
of your choice.

It's a bit messy to do should be VERY carefull of the signal
integrity of the sense wires, while keeping scan time below
level that the HEX pick-up will hear. The HEX-pick up in this
case is not part of the above circuit, it could be used straight
running different strings to different effects, or to circuits
using VCO's and VCA's or both at the same time.

With a micro-p in-line you could get excellent proformance
capablity like:
	ARE MORE THAN THREE STRINGS ACTIVE?
	YES-LATCH THOSE NOTES UNTIL NEXT SIMILER EVENT.
in effect a "chord hold" you could then play fills over
that chord, then play then next chord. No nasty cueing switchs.

I'm going in for a yamaha DX9 digital synth, I would dearly
love for this scam to work-out. But the more  think about it
the more trouble I know I'm going to have with the switching
pulses running on the strings directly over the pickup.

Anyone know of an attempt of this nature that didn't work out?
I'de like to know before I hack up an EXPENSIVE strat neck.

John

	Well scratch the sense wires on the neck idea.
	Most people (me included) would finger the fret
	before strokeing the strings so the computer wouldn't
	know where to get the cue to start the envelope from,
	the sense wires or the triggering via the pick-up.
	This would make trouble when you wanted to do a slide also.

	However, you could introduce a analog to digital converter
	into the phase-locked-loop circuit and convert the frequency
	information (represented by the voltage proportional to the 
	frequency from the PLL) into digital data, then format that
	into MIDI command conventions to send to a EX-800 (korg) or
	EX-600 (siel). Since the PLL only has to work over a range
	of two octaves/per string (6 PLLs, 1 per/string) the frequency
	capture time should be relatively small. 
	Has anyone seen/know about the DX9&7 expander?$?$?

John

I have also thought of different ways of constructing a switching
matrix out of the natural 6x24 (or however many frets you have)
matrix that guitars are based on.  I too was stopped by the realization
that on a guitar the fretting action has to be separate from the picking
action for it to play like a real guitar.

Enter Edward van Halen.   His bizzare, flashy style has introduced
a whole new way of playing the instrument.  The overhand style that
was first heard on "Eruption" the intro to "You really got me" on
Van Halen I is now used by many metal guitarists, as well as some
from other genres.

Now re-think the design of a guitar neck switching matrix with 
overhand playing in mind.  This led me to wonder if it might not
be a bad idea to start from scratch and dispense with the strings
entirely.  Consider an array of soft-rubber pads, divided by a matrix
of harder plastic, wood or metal strips.  Under each pad would be
a printed-circuit pressure switch.  If you've ever had the misfortune
of trying to repair an Atari 5200 joystick controller you know the
kind of switch I mean.  It looks like clear Mylar with printed
circuits in it.  Properly designed, the rubber pads would be higher
in cross-section than the dividers, but easily compressable down
to the level of the dividers.  This would allow you to play barre
chords and other normal guitar fretboard manuevers.  It would also
be real easy to blast off real fast overhand sequences with perfect
even dynamics on every notes.

Then put another set of controllers down where the pickups belong.
There would be one for each string, but how they should work is
a good question.  There could be an organ-like infinute sustain
button for each string, or a small percussion pad that would get
piano-like envelopes.  You could add after-touch sensitivity to
control pitch bend, LFO or filter modulation etc, etc, etc.
I'd like a sortof multi-function controller that would have 
different sections on it for different sounds.  Also, a lever
to bend the pitch of all six strings ala whammy bar would be nice.

Sure it's complicated, but so is a saxophone.  Ergonomics in
design would have to be a major factor, since it won't be worth
shit unless someone likes to play it.  

Also, the printed circuit switches would be very cheap to
mass-produce if it came to that.  The whole fretboard could be
"printed" in one shot.

					-Jeff

   Re: 24.7, 24.8 and 24.9

   A (I think) British firm has developed a MIDI guitar controller 
   called the SynthAxe that uses the string contacting fret principle
   for selecting pitches.  However, it uses a separate set of strings
   for strumming and picking; these strings determine the MIDI note-on,
   note-off commands.  It also has a twang (vibrato) bar that sends
   pitch bend commands.  The net result - no tracking problems, a 
   vibrato that stays in tune regardless of how you abuse it, "strings"
   that are all the same gauge, frets that are equally spaced on the 
   neck, etc..  It has other features, like a keypad per string that 
   allows you to play it sort of like a keyboard or for drone effects.

   The only problem is that it's rumored to cost about $10000.  Like a
   Kurzweil, it's probably out of the reach of most of us, but it sure
   sounds like the right way to build a guitar controller.

wow

    Hello ....  anybody there???
    
    By looking at the date on the last reply, I'm not sure if anyone
    will see this, but here goes. While accidently (or on purpose) going
    through the easynotes list I came across COMMUSIC. I have enjoyed
    as well as learned a few things in my reading from this fine notes
    conferrence. Note 24 really caught my eye as for the last few weeks
    I have been seriously considering building a guitar synth myself,(to
    the point of using up my spare time reading, researching, drawing,
    contemplating,...). Right now I'm wondering how your synth attempts
    came out and what the final result was. So if your still watching
    this note, let me know cause I'm quite interested in cold beer,
    power chords on electric guitars, and guitar synths.
    
    Brad 'Toto, I have a feeling were not in Kansas anymore' Trombley
    
    

    Technology passed me while I was busy working for Uncle DEC.  Most of
    what I proposed has been implemented by one guitar synth manufacturer
    or another, and now MIDI is a must, and pitch-to-voltage is pass�. 
    
    There were no attempts, just a lot of blowing smoke.
    
    Just think, if I had M$ (mega-dollars) and an engineering staff
    four years ago, I might have been a success !  Those is the breaks...
    
    BTW, the CES (curtis) chips were used in many of the commercially
    successful analog and digitally controlled analog synths of the
    70s and early 80s; the Sequential Circuits stuff in particular.
    Recommended reading is the article on "20 great electronic music
    inventions of the past 20 years" (loosely paraphrased) in a recent
    issue (2 or 3 months back) of "Music Technology", or maybe it was
    "Electronic Musician".  A real gem of an article.  If I run across
    it I'll post the exact reference.
    
    Good luck, and please keep us informed of your progress.
    
    						-Jeff