[sdiy] Speaking of guitar synthesizers

[harrybissell]

Gar... what is this ?  BAIT to draw me out of hiding ???

Wired Fret systems exist. The most simple is the 'guitorgan' which connected
the strings and frets to play organ sounds.

Problem is the chords.  Most guitar chords have fingers on adjacent frets...
Strings that are depressed (no prozac?) touch the fret nearer the bridge, and
the
one nearer the neck... so playing a chord usually shorts many frets out at once.

One way to solve this is to cut the frets into six pieces.  If you cut them at a
45
angle you can still bend the string.

Straight 'wired fret' systems do not allow bending, unless coupled with a P/V
or some angular sensing system.

There are ways around the string shorting problem... one elegant way was
patented
by Roland... and used current sensing coils under each fret.  A constant current
source
was scanned to each string, and because the first fret encountered is 'likely'
the one that gets the lion's share of the current... you can tell the true fret
position.

There are some systems that use resistive strings (hard to find :^) and
resistive
frets (hard to find a good workable material...)

I was going to make a system using NON CONDUCTIVE strings... and sense using
a capacitive method to plates inbetween the frets. Elixir strings are
non-conductive
right ?   Right... but only the WOUND ones. The solids are plain steel (too bad
so sad!)

I believe the wired pick is patented (and expired iirc) as well... problem is
there are so many ways to play... finger picking with / without picks,
different pick sizes, stiffness...

The idea of using a simple, wired fret system to make a better guess of the P/V
method is really worth exploring. I have been planning on trying it myself...
otoh
there is still a lot of mechanical details to work out.

Knowing exactly when the sting is hit is probably the easiest thing to know...
almost
always there is a very large transient that exponentially decays.  No wired pick
is really
needed.

If you want an idea (clue :^) use this... have a way to sense if the string is
fretted at or above the 12th fret... and have a way to detect an open vibrating
string. P/V will do the rest.

(I have such a system now, it is really complex... almost enough to make a
custom
guitar worth doing).

Another problem, everyone likes their own guitar... some are really expensive
and
not to be cut up.  Some are set so low that they buzz, and that will kill any
P/V system
~or~ a wired fret system

Not that you are building a guitar synth (I am :^) but here's a counter-idea to
the
wired pick (because a wire on a pick would just SUCK. not BBD suck mind you...
just suck :^).   Why not make the pick of a conductive substance... and impress
a high
frequency (RF) wave on the string... and sense when the capacitance of your hand

dampens the oscillation. Then you don't need the wire.

OTOH the wire could be marketed as a feature...

"NEVER DROP YOUR PICK AGAIN !!!"    :^P

H^) harry

Tim Parkhurst wrote:

> Okay, so we all know that pitch to voltage conversion is tricky at best, but
> are there other systems that have been tried (either instead of, or in
> addition to P-V)? I was thinking of two things: first, the 'wired fret'
> systems. Of course, this has been done before, but how well do they work?
> Also, do these systems use the fret sensing to aid P-V converters (to narrow
> the range of pitch possibilities), or do they dispense with the conversion
> altogether? Secondly, I was thinking of a 'wired pick' so that the system
> knows exactly when a string is hit. Of course, there are hammers and other
> techniques that would fool such a system, but would a system with wired
> frets AND a 'wired pick' AND a good P-V be an improvement, or would it just
> be overkill? Do you think the 'wired pick' is an idea worth pursuing? (very
> simple to implement, could be set up so that the system would know when a
> string is hit AND which string is hit, perhaps even toss the entire wired
> fret thing altogether...)
>
> Your thoughts? I'm not looking to build a guitar synth, but I just thought
> the 'wired pick' / active pick / whatever you want to call it was an
> interesting idea.
>
> Tim (picky, picky, picky) Servo
>
> "Imagination is more important than knowledge." - Albert Einstein
>
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