DIGITAL GUITAR AUTO-TUNER PROJECT - Page 5

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Re: DIGITAL GUITAR AUTO-TUNER PROJECT

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The converse of a statement proves nothing.  ;-)

--
  Keith

Re: DIGITAL GUITAR AUTO-TUNER PROJECT

   ...

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Oh? I thought it proved the converse.

Jerry
--
Engineering is the art of making what you want from things you can get.
ŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻ

Re: DIGITAL GUITAR AUTO-TUNER PROJECT

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No, I think you'll find that it does _not_ prove the converse.  ;-)

--
  Keith

Re: DIGITAL GUITAR AUTO-TUNER PROJECT
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You mean that proving the converse doesn't prove anything? Oh, I get it!

The converse of something is nothing.

Proving the converse of something proves nothing.

Ah, so!

Jerry
--
Engineering is the art of making what you want from things you can get.
ŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻ

Re: DIGITAL GUITAR AUTO-TUNER PROJECT
Followup-To:

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And now for something completely off-the-scale:

While I'm barely at the "hacker" stage in my DSP knowledge (I'm
still working out how modulating a reflected mm-wavelength signal can
yield accurate distance measurement over thousands of mm), I have
been following the threads in this Subject-line with great interest.

I'm particularly fascinated with the complexity of obtaining a
"useful" or "pleasing" tuning for a musical instrument.  I hadn't
realized that there were multiple "standard" ways of tuning a piano,
for example.  Thank you all for giving me an excuse to renew my
Usenet Lurker's License. <grin>

I'd like to ask one question, though, regarding the tuning process
for instruments involving mechanical vibration -- not just the ones
someone referred to as "plucked" but also percussion instruments and
probably others.  If, as some have mentioned, the tuning of stringed
instruments is made more difficult because people pluck the strings
differently (is this the same as "attack".  or is that a "keyboard
only" term?)  and the sound changes over time (decay), why not add a
feedback loop into the process?

That is, why not have the "tuning instrument" induce the vibration
as well as analyze the resulting sound.  A PWM-speed-controlled
motor with a _gentle_ off-center cam is probably not the only
approach.  but it doesn't seem very difficult to do (certainly no
more difficult than analyzing the pure sine wave coming from a
guitar string <grin>).

Is there a reason that "tuning instruments" (at least, the ones
I've seen and the ones discussed here) only analyze sounds and don't
attempt to apply controlled signal stimulation?  Or is it that such
already exist and are simply too expensive for everyday use?


(Whoops! I think I just violated my ULL! Time to re-cloak... er,
 re-Lurk. <grin>)

Frank McKenney, McKenney Associates
Richmond, Virginia / (804) 320-4887
Munged E-mail: frank uscore mckenney ayut minds pring dawt cahm (y'all)
--
   "Very few things happen at the right time, and the rest
    do not happen at all. The conscientious historian will
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Re: DIGITAL GUITAR AUTO-TUNER PROJECT
   ...

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My guess: generating the sound is usually something that comes so easily
to a musician that it's not worth automating. Something was published on
a piano tuning device that both excited the string -- I forget how --
and turned the tuning peg with a geared servo motor. A human had to
place the string-isolating wedges and move the servo from peg to peg.

Jerry

P.S. Is your name really Frank?
--
Engineering is the art of making what you want from things you can get.
ŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻ

Re: DIGITAL GUITAR AUTO-TUNER PROJECT
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I read something about a self-tuning piano. It used a magnetic pickup (as
for an electric guitar) to sense the frequency. Presumably they excite the
string the same way, by driving a current through the pickup coil.

I think that was the piano where all the strings were tuned sharp and to
tune a string a current was allowed to flow through the string, heating,
lengthening and flattening it. If they used a pickup instead of a microphone
then they could tune multiple strings at once without them bleeding into
each other. Very clever.

Jonathan
http://cq.cx /



Re: DIGITAL GUITAR AUTO-TUNER PROJECT
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Maybe it would make sense for something like piano, but consider that guitar
tuners cost about 20 bucks and can fit in a back pocket.  Adding some for
stimulation is going to be pretty expensive compared to that, plus as Jerry
said, musicians are pretty good at plucking their own strings!  Plus, I don't
many people that would trust a machine "banging on" their expensive instruments.

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I was wondering the same thing.



Re: DIGITAL GUITAR AUTO-TUNER PROJECT
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instruments.
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Somewhere in the attic, I have an oak box with a tuning fork mounted on
it. One tine of the fork is driven by a coil and the other drives the
button of a diaphragmless carbon microphone that modulates the coil
current. Coil voltage is available on binding posts. At one time, it was
General Radio's premier 1 KHz frequency standard. Feeding back to a
mechanical resonator has been done for a long time.

Jerry
--
Engineering is the art of making what you want from things you can get.
ŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻ

Re: DIGITAL GUITAR AUTO-TUNER PROJECT
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instruments.

I've heard of those "self-tuning" pianos, and from what I've heard,
hearing it tune itself is almost a transcendental auditory experience. %-}

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World's first "Accutron"! :-)

Cheers!
Rich



Re: DIGITAL GUITAR AUTO-TUNER PROJECT
On Thu, 28 Apr 2005 14:58:04 -0700, "Jon Harris"

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A guitar already has a mag pickup, so it should be possible to just
plug it into a tuner (with vol and tone right up) and have the tuner
search for the slight narrow-band impedance resonances at each string
pitch, then use that to sustain continuous oscillation. Of course it
would probably also pick up harmonics of other strings if they weren't
damped (ideally need access to a hex pickup as well, I guess). A
practical design would be tricky, but still quite cheap.

Tony (remove the "_" to reply by email)

Re: DIGITAL GUITAR AUTO-TUNER PROJECT
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I assume you are talking about using the pickup in reverse, i.e. to drive the
strings to vibrate?  Well, it's true that _some_ guitars have passive magnetic
pickups.  But others have different types including active pickups.  With active
pickups, you can't just reverse drive them from the 1/4" input--the output
buffer gets in the way.



Re: DIGITAL GUITAR AUTO-TUNER PROJECT
On Fri, 29 Apr 2005 17:07:25 GMT, "Jon Harris"

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active
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Not just in reverse - by incorporating the pickup in an impedance
controlled oscillator it can act in both directions at once. I doubt
that losing a few % of the market (guitars with active pickups) would
be an issue for such a niche market device, although guitars with ONLY
piezos and pre-amps would be significant loss. Some guitars already
come equipped with crude feedback built in for "sustain" (generally
using separate pickups for sensing and actuation), but not selective
enough for this application.

I only tossed in the concept to illustrate that there are other
options (in the spirit of the discussion); if I really thought it was
going to set the world on fire I'd probably not publish it here. And
in any case, that's only a small part of the tuning loop - the most
important bit is mechanically adjusting each tuner, which isn't likely
to be automated until someone builds a complete low loss tuner block
that actually replaces conventional tuners (rather than attaching to
them). Even that isn't a big challenge technically, but as always, the
guy develops the first one could lose his investment if the market
isn't ready.

Tony (remove the "_" to reply by email)

Re: DIGITAL GUITAR AUTO-TUNER PROJECT
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guitar
don't
magnetic
active

Thanks for the clarification.  I come from the acoustic guitar world, where the
vast majority are piezo and/or pre-amps, rather than a niche market.  For
electric guitars, you are probably right.

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OK, point taken.



Re: DIGITAL GUITAR AUTO-TUNER PROJECT

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Electric guitarists have been doing this acoustically since they
discovered feedback. I guess there's a whole mystique (sp?) about
the process - I think they toss the term "sustain" about. (my brugly
other is a professional guitarist, on the side.)

Cheers!
Rich


Re: DIGITAL GUITAR AUTO-TUNER PROJECT

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Please translate "brugly" for me. I'm still trying to learn.

Jerry
--
Engineering is the art of making what you want from things you can get.
ŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻ

Re: DIGITAL GUITAR AUTO-TUNER PROJECT
In
sci.electronics.design,sci.electronics.misc,comp.dsp,comp.arch.embedded,

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   Know what a Spoonerism is? "brugly other" :)

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-----
http://mindspring.com/~benbradley

Re: DIGITAL GUITAR AUTO-TUNER PROJECT

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As a fadder of mact some people say things verse visa.

--
  Keith

Re: DIGITAL GUITAR AUTO-TUNER PROJECT

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"Hi. I'm John Audubon. I watch birds."
"Hi. I'm Bill Spooner. I watch birde."

;-)
Rich


Re: DIGITAL GUITAR AUTO-TUNER PROJECT
GUITAR AUTO-TUNER PROJECT', on Sat, 30 Apr 2005:

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  "Hi. I'm Rich Grise. I jotch bokes."
--
Regards, John Woodgate, OOO - Own Opinions Only.
There are two sides to every question, except
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