DIGITAL GUITAR AUTO-TUNER PROJECT

[Rich Grise]

My colleague, John Bowsher (a physicist as well as a trombonist)
demonstrated this to an AES British Section meeting many years ago. Two
demos:

- producing a constant pitch note while collapsing the slide.

- producing a swept pitch note with the slide stationary.

I don't really believe it, and I was there!

Embouchure, comrades, iron embouchure!

Cheers!
Rich

 

[Rich Grise]

On Fri, 29 Apr 2005 13:36:23 GMT, David Tweed wrote:


I's have to disagree on the synthesizer. With pitch benders, modulation
wheels, breath controllers, etc... the performer has at least as much
control over pitch as a tromboner. Leads to some gawd-awful playing too.

Ever played "Taps" or "Tantara" on a flute? ;-)
You really have to overblow it! (joke bait semi-unintended, but noted. ;-) )

Cheers!
Rich

 

[Jerry Avins]

A trombone will be played out-of-tune by a bad player and will not be
touched by a good player. Same thing for the soprano sax and oboe.

In all seriousness, I would much rather play trombone than trumpet (my
two main axes) in a large ensemble because it's so much easier for me to
adjust the pitch while I play.

Your trumpet is too pretty. The bugler in Boy Scout camp played so
beautifully that he could bring tears of joy to listen to him noodle.
The camp bugle was battered from years of abuse, ans the Campmaster, a
Presbyterian minister in real life, thought it a disgrace to his
administration. He replaced it with a shiny new one, lacquer intact, a
joy to behold. It sounded awful, with sour notes that resisted all
skill. Campmaster refused to return the old instrument, claiming that he
had disposed of it (a lie). The bugler, a fine trumpeter, was literally
in tears, berating himself for not having his trumpet with him.
Trumpeter and I retired to the woods with a variety of implements: a
broomstick, pieces of firewood, and a blackjack made from a rock encased
in six socks. We took turns "distressing" the poor bugle, at one point
denting it in so deeply that we needed the broomstick to round it out.

Hearing the sweet sound again made Campmaster come running to gloat that
the instrument was fine, that as he had said all along, practice would
make perfect. Boy Scouts don't lie. Bugler said, "We fixed it" and
proudly displayed the dents. "The prof helped." Thanks a lot!

Jerry

 

[Jerry Avins]

... (my brugly other is a professional guitarist, on the side.)

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

Jerry

 

[Ben Bradley]

In
sci.electronics.design,sci.electronics.misc,comp.dsp,comp.arch.embedded,

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

Know what a Spoonerism is? "brugly other"

 

[Tony]

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.

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)

 

[Jon Harris]

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.

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.

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.

OK, point taken.

 

[Jon Harris]

Your trumpet is too pretty. The bugler in Boy Scout camp played so
beautifully that he could bring tears of joy to listen to him noodle.
The camp bugle was battered from years of abuse, ans the Campmaster, a
Presbyterian minister in real life, thought it a disgrace to his
administration. He replaced it with a shiny new one, lacquer intact, a
joy to behold. It sounded awful, with sour notes that resisted all
skill. Campmaster refused to return the old instrument, claiming that he
had disposed of it (a lie). The bugler, a fine trumpeter, was literally
in tears, berating himself for not having his trumpet with him.
Trumpeter and I retired to the woods with a variety of implements: a
broomstick, pieces of firewood, and a blackjack made from a rock encased
in six socks. We took turns "distressing" the poor bugle, at one point
denting it in so deeply that we needed the broomstick to round it out.

Hearing the sweet sound again made Campmaster come running to gloat that
the instrument was fine, that as he had said all along, practice would
make perfect. Boy Scouts don't lie. Bugler said, "We fixed it" and
proudly displayed the dents. "The prof helped." Thanks a lot!

Great story! What do you think made the difference? I've heard that removing
lacquer opens up the sound slightly, but have never known anything good to come
from dents. Any explanation?

 

[Jon Harris]

Embouchure, comrades, iron embouchure!

How much did he vary the pitch by in the second example? I can change the pitch
maybe a half-step either way on my French horn using embouchure, but not much
more than that.

 

[Kelly Hall]

How much did he vary the pitch by in the second example? I can change the pitch
maybe a half-step either way on my French horn using embouchure, but not much
more than that.

Partials on a french horn are so close together that it's hard to lip
much before the horn refuses to play along and just moves to the next
partial. One of the typical trumpet books (Maggio? Stamp?) has a series
of exercises where you first finger and then lip down a half-step. Back
in my serious days I took it down to major thirds.

Once you get used to holding your embouchure in spite of the horn not
wanting to resonate, it's a lot easier to play those false notes. It's
the only way to play the trumpet notes between low F# and pedal C with a
3-valve horn.

There was a Boston Pops concert on PBS a few years back with Arturo
Sandoval playing a pretty ballad on his flugel - he played a number of
notes below f# and they sounded fantastic: big, full, pretty. And the
fact that 98% of the people listening didn't notice (or care) was the
best part: it wasn't some gimmick to lay onto the kids at a clinic, he
was just making music

Kelly

 

[keith]

In
sci.electronics.design,sci.electronics.misc,comp.dsp,comp.arch.embedded,


Know what a Spoonerism is? "brugly other"

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

 

[keith]

How much did he vary the pitch by in the second example? I can change the pitch
maybe a half-step either way on my French horn using embouchure, but not much
more than that.

I'm skeptical too. ...at least without losing all tone. A trombone (I
was a t-bone player in HS) is a 2/3 straight 1/3 conical instrument (like
a trumpet). A baritone (cornet) is the opposite, so has a lower Q and
can be shifted more. I don't recall the straigh/conical ration of
a freedom horn, but given it's lack of stright sections it has a low Q,
which is why it's a bitch to play.

 

[keith]

Great story! What do you think made the difference? I've heard that removing
lacquer opens up the sound slightly, but have never known anything good to come
from dents. Any explanation?

Dents lower the Q? ...allowing the _musician_ to play it as he wished.

 

[Kelly Hall]

Great story! What do you think made the difference? I've heard that removing
lacquer opens up the sound slightly, but have never known anything good to come
from dents. Any explanation?

Brass intruments are dominated by second and third order effects, so
it's really hard to get conclusive explanations. Particularly when the
player is an active part of the feedback loop (ears - chops - horn -
sound). Often, a little resistance in the horn helps the player move
more easily between the partials. Just as often, thinking that the horn
will sound/play different/better is enough to make it so.

Kelly

 

[John Woodgate]

I read in sci.electronics.design that Jon Harris

How much did he vary the pitch by in the second example? I can change
the pitch maybe a half-step either way on my French horn using
embouchure, but not much more than that.

I don't know exactly, of course, but more than an octave.

 

[Rich Grise]

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

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

;-)
Rich

 

[John Woodgate]

I read in sci.electronics.design that Rich Grise <[email protected]>

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

"Hi. I'm Rich Grise. I jotch bokes."

 

[Glenn Gundlach]

Dain bramage perhaps?
GG

 

[Jerry Avins]

In
sci.electronics.design,sci.electronics.misc,comp.dsp,comp.arch.embedded,



Know what a Spoonerism is? "brugly other"

Gotcha! No need to sew me to a sheet.

Jerry

 

[Jerry Avins]

Great story! What do you think made the difference? I've heard that removing
lacquer opens up the sound slightly, but have never known anything good to come
from dents. Any explanation?

I thought I knew what I was doing when I did it, but (as always) I'm
open to correction. I had read (and still believe) that because baroque
horns were hand made, therefore slightly irregular in the bore, they had
lower Q, making it possible -- though difficult -- to play without
valves. (Horn players were the elite of baroque orchestras, usually
seated on a raised platform as, I read, a mark of honor.) Baroque
mouthpieces had relatively larger bores, too, making the player's mouth
part of the resonant cavity. Valves were first used to make playing
easier. It seems likely that when machine-made instruments made nearly
impossible to play without valves, nobody noticed. I could do little
about the mouthpiece, but it was easy enough to "modify" the bore. Not
needing a section with valves, a bugle's bore is more conical than a
trumpet's, hence more compliant to the player's skill.

That trombone that was pulled a long way: was there anything special
about the mouthpiece?

Jerry