My Tyros got nice accordion sounds, but I wished I could somehow add that missing bellow shake. I was thinking that might somehow be possible? So, far my limited electronics knowledge led me to think of achieving it in one of these ways:
Roland accordion's "Innovative Dynamic Bellow" has it, too. I wonder how they created it?
- It might be possible to do it with the 3-axis accelerometer, because it can be adjusted to volume control of the Kbd. So, by shaking the hand this effect can be created and varied? Important is that the effect changes start (like reeds) from "0" and has steep envelop patterns; almost like a tremolo. i wished to find out how the Roland bellow control works?

My two project ideas are:
1) It might be possible to create that "sawing type" of bellow shake via LDR light variation or via a pressure sensor?
My old Elka49 organ had such a foot volume pedal. It had a little black box. Inside was a division wall with a width increasing slot, through which a bulb light beam was directed at an LDR. One one side was the bulb light and on the other side was the LDR. So, when the slot size increased, more light hit the LDR and the organ volume increased!
This process could be RF controlled via a finger mounted ring gadget, like in HotHand. The light slot slider could even trigger a slightly different filter, emulating minute timber change of reeds. So, the idea of a light controlled gadget with remote control is not a bad idea, after all...

2) My other, an even better idea, is to use a Mini Mercury switch on a finger ring to control the on/off chord volume via a tiny RF transmitter. This switch could also control a little circuit, which tailors the sound's envelope; i.e. for instance filter the sound every second shake to compensate the slight reed changes. A tiny low voltage filament bulb (not LED) has a small turn on/off drag, simulating accordion reeds. This bulb then sheds its light onto a sensitive LDR, controlling the Tyros Kbd. chord sound. I also got that Yamaha MFC10 MIDI controller and parallel wired its high quality 10K foot volume/expression pedal. So, any LDR responds perfectly.

So, what's your take on that? Since your electronics knowledge is able to think of even better solutions, I would be delighted if you could kick me to success. I'm a young pensioner (75) and enjoy playing wonderful sounds and melodies. Adding that bellow shake variations would enrich any melody in many ways. I attach some interesting data, which might help to pinpoint what I'm after:
https://app.box.com/s/brj4xktxo1tv3xa8m832nbnr4hx0fnoz

 

How are your programming skills?
I would think a PIC or similar could easily generate a series of MIDI velocity change commands in response to a trigger on an input pin.

 

My Tyros got nice accordion sounds, but I wished I could somehow add that missing bellow shake. I was thinking that might somehow be possible? So, far my limited electronics knowledge led me to think of achieving it in one of these ways:
Roland accordion's "Innovative Dynamic Bellow" has it, too. I wonder how they created it?
- It might be possible to do it with the 3-axis accelerometer, because it can be adjusted to volume control of the Kbd. So, by shaking the hand this effect can be created and varied? Important is that the effect changes start (like reeds) from "0" and has steep envelop patterns; almost like a tremolo. i wished to find out how the Roland bellow control works?

My two project ideas are:
1) It might be possible to create that "sawing type" of bellow shake via LDR light variation or via a pressure sensor?
My old Elka49 organ had such a foot volume pedal. It had a little black box. Inside was a division wall with a width increasing slot, through which a bulb light beam was directed at an LDR. One one side was the bulb light and on the other side was the LDR. So, when the slot size increased, more light hit the LDR and the organ volume increased!
This process could be RF controlled via a finger mounted ring gadget, like in HotHand. The light slot slider could even trigger a slightly different filter, emulating minute timber change of reeds. So, the idea of a light controlled gadget with remote control is not a bad idea, after all...

2) My other, an even better idea, is to use a Mini Mercury switch on a finger ring to control the on/off chord volume via a tiny RF transmitter. This switch could also control a little circuit, which tailors the sound's envelope; i.e. for instance filter the sound every second shake to compensate the slight reed changes. A tiny low voltage filament bulb (not LED) has a small turn on/off drag, simulating accordion reeds. This bulb then sheds its light onto a sensitive LDR, controlling the Tyros Kbd. chord sound. I also got that Yamaha MFC10 MIDI controller and parallel wired its high quality 10K foot volume/expression pedal. So, any LDR responds perfectly.

So, what's your take on that? Since your electronics knowledge is able to think of even better solutions, I would be delighted if you could kick me to success. I'm a young pensioner (75) and enjoy playing wonderful sounds and melodies. Adding that bellow shake variations would enrich any melody in many ways. I attach some interesting data, which might help to pinpoint what I'm after:
https://app.box.com/s/brj4xktxo1tv3xa8m832nbnr4hx0fnoz

I think an accelerometer with analog output is a great idea. Couple that with a varactor connected between signal and ground to attenuate the signal when the accelerometer goes high on a given access.

 

I still haven't found a genuine bellow shake emulation for my Tyros. - I managed to get near it, yet when I look at the bellow shake wave, I noticed that it consists of gradual hill up and hill down shapes, whereas my recorded bellow shakes look like hacked sound samples. On an accordion bellow shake the air first gradually mounts, then stops and then reverts. Albeit that happens fairly fast each sample goes through these 3 stages.
Since I wouldn't know how to PIC program such a bellow shake volume pattern, I thought of building a little LDR box, in which a spring suspended LED or a small bulb moves across a two sided v-shaped slit.
After lots of trial & error I might be able to faithfully emulate the impressive volume changes of an accordion bellow shake. - It's quite a valuable addition to any Synth, because it adds emotional presence to the otherwise cold electronic sounds. Years ago, I used to play the accordion and now plan to build myself a light-weight 5 row-JANKO accordion with a keyboard made from PC keys switches.
I already converted a 120-button accordion bass (bass section only) to MIDI for it. It was a hell of work, for I had to combine and solder all its chords manually via some 200 signal diodes so, that each button activates only one soft contact. The buttons now work far lighter than the buttons of a normal accordion bass. - Here's a picture of the 120 button accordion bass conversion to MIDI:

 

Not having listened to much accordion music it would be useful to have an explanation of what you mean by bellow-shake. Is it a variation in pitch of the note, or in amplitude? Guitar music has tremolo, a variation in amplitude, and vibrato, a variation in pitch, and those functions are able to be duplicated electronically quite well. There are also hundreds of add-on effects for guitars and so if you can provide a description in more technical terms it is very likely that an answer already is available.

 

Still not one mention about what "The Shake" does to the sound. Lots of talk about betting a control voltage but no words on what that voltage will do. It is difficult to see a solution when the problem is unknown.

 

Sorry MisterBill2, you are right I should first have answered your question.
Here's a good Demo of a bellow shake:

I cannot find or create this effect on my Yamaha Tyros. When I analyse the sound waves of bellow shakes, we can see the volume volume variations. It shouldn't be that complicated to implement them.
Since I'm not into PIC programming, I think for me it's just a matter of of designing a light path LED slider, which regulates the amount of light getting to the LDR as to faithfully emulate a bellow shake volume curve. My foot pedal has a 20K Ohm Pot, which I connected to a LDR. That allows me a degree of volume variation when I run a light onto it.
Warm Regards, from young pensioner Jo (78) in Townsville, Australia

 

OK, so the effect is a variation in amplitude. That could be implemented directly with the pot in your foot pedal, quite simply using it as an additional volume control. AND there are hundreds of guitar effect circuits around, and one of those may also do what you seek. The effect you describe sounds like a variation of the guitar amplifier tremolo effect, except under player control. That circuit may not be accessible in a synthesizer and so you would need an external circuit. The caution that I suggest is that with varying the current to a light source the wear on a pedal controlled variable resistor may be more than you want, leading to a shorter life of the variable resistor.
And as for using some digital scheme with a program, it seems that there are a huge number of folks who are unable to do any analog designing and think that a micro is the only way to do things. I pity their lack of insight and ability. There are definite places for digital technology, but not everywhere.

 

It took me only some 3-4 weeks to realize my Janko accordion keyboard dream. Of course to turn an old 120-button accordion bass into Midi was far harder, because I didn't want to use the mechanics and so, had to manually wire up all basses and chords. Result:: each button activates only one tiny (gold-silver) contact wire; meaning the buttons are super-light to press. Now I only had to add the "v3 accordion master xl" module and so, I together with my project I got my hands onto a great JANKO MiDi accordion... on the cheap, which rivals those expensive Roland Midi accordions.!
Here are some Pics and the accordion bass sound of it:
https://app.box.com/s/obooqxseq1q6ofnyxgsbfhm23qghqjpg