120-button (single button contact) accordion bass section to MIDI

[jjj]

For years I used to play the piano accordion and now that I own the Yamaha Tyros 3, I missed the convenience of playing the accordion bass section, for it's so much easier than manually playing the chords. That's why I thought to connect an old accordion bass section to MIDI and
just successfully finished wiring up my 120-button (with single contacts) Farfisa accordion bass section to MIDI.
Result: It's amazingly compact! The single contact makes ea. button even lighter to press than a regular, mechanical accordion bass!

On a mechanical bass each button has to open 3 to 4 air flaps and with additional spring contacts the buttons are getting pretty hard to press.
Jeez, that was a crazy job! It took my 3 weeks to get it right. It looks pretty messy, but it works and sound truly great. I'm excited about the result!
The thing I like most on it is that it offers me (accordion player) the chance to combine manual and Yamaha styles accompaniment.
Now I am able to manually enrich and vary the bass +chords and so, make it the great sounding Yamaha styles automatic accompaniment sound "far less automatic".
Since I was unable to attach the project details, I uploaded them here: https://app.box.com/s/994hzfqhsnjksguqa22t

My last challenge is to recreate that typical accordion "bellow shake", which at the same time controls volume and tremolo variations, like on an accordion. That creates emotional presents! The foot pedal delivers not quite the same. Maybe you got an idea on that?
My initial idea is to place the whole bass section onto soft springs, which make it easy to wobble. I suppose I'll have to do a few different mechanical wobble test setups to find the best working one.

I then also need a volume control for it. I have got a "Morley" volume pedal circuit, with the TDA1524 stereo Vol control chip, which uses a LDR with lamp, but fear the LDR's reaction timing will be too slow...? How to increase its speed?

[Mick Bailey]

I was wondering if a 3-axis accelerometer IC would be a starting point for the bellow dynamics. They're commonly available mounted on a small PCB for Arduino and similar interfacing. There are also gyro-accelerometers which give 9-axis readouts. If you did go the Arduino way there's plenty of sample code and support.

You'd need to establish what dynamics have to be captured. Then to map out how each dynamic would resolve into a digital or analogue control signal or midi data.

I don't think this is a simple solution. In effect, for a personal one-off you've got to go down the same path as developing a commercial product because the end-result needs to be at least as good (if not better) than something you'd buy commercially. But that's the challenge - to build a better mousetrap, as they say (or as Emerson said).

If your volume pedal has lamp rather than LED you'll get some 'bulb latency' which can be improved be changing it to an LED and series resistor. The LDR is possibly yellow-green sensitive. If so try a yellow or green LED rather than red as a better match. Other than that you'd need to determine the light and dark resistance of the LDR and look at manufacturer's data sheets to keep to the same resistance characteristics, but pick the fastest device. Possibly Silonex would be a good start.

[jjj]

Thank you dear Mick Bailey for your very professional ideas and advice. For me at 71+, these things get a bit out of hand. I "should have" aimed for electronics engineering, but then again there are too many things I should have aimed for... and for that I need to live at least 300 years. I'm glad I was able to get this far,
for I'm also into mechanics, plumbering and fixing Chinese products with obsolescence timers and inventing and building useful gadgets unavailable on the market: even into playing my Tyros, producing recordings in which I whistle to music classical/Pop music and writing books full of creative, original philosophical insight.

I couldn't be the only one, interested in getting this project working. At least I already spilled the main details of how to convert an old accordion bass section into a useful MIDI accompaniment for accordion players. The very fact that I sold the lousy mechanical one on eBay proves that there's is demand for it, because there is non of these on the market for under $1000 +.
Yes... ultimately I'll have to fiddle around with different LDR and LEDs and continue my search for some suitable circuits.

Breaking News! Hold on...pondering about it, leads me to another good idea: converting the circuitry from the Vol pedal of my "Yamaha MFC MIDI Foot Controller" !!! That one is pretty responsive. Since there's nothing I cannot get my hands on, I'll open it and see...
Yes, I think that will do the trick! So, I thank you again for having at least led and kicked me to more pondering and to success!
The other day an elderly lady showed me the way and on that way I found $20 in the gutter... and this time I was lucky again!

No wonder, my brother calls me: "Hans Im Glueck!"
Warm Regards, from Joh in St'go de Chile

[Mick Bailey]

Ha! You'd give the kids (and me - sadly no longer a kid in body, but still in mind.....) a run for their money with what you've achieved already. I wish you well, that's a nice inventive project.

[jjj]

Progress Report:
In the meantime I did some testing and discovered that connecting a cable to the 10K potentiometer in my Yamaha's MFC10 Midi-Foot controller allows me to operate this foot controller's circuitry via an LDR on the 120-button box. The LDR with a yellow-green LED is surprisingly fast, because the foot pedal's circuitry works via MIDI (!!)
As mentioned, my initial idea was to place the whole bass section onto soft springs, but today I discovered that every time I change to another chord position, my hand won't press the box down and the volume level will decrease considerably.
So, I thought of rather novel idea: creating a v-tilt underneath the unit with soft rubber strips and thus, tilting/tipping the unit slightly forward for more Vol and back for less Vol. That way, the 120 button box stays in either lower or higher Vol position during chord changes. This makes it equally easy to create bellow shakes and tremolo and Vol changes.
Yes, as you see ...I'm getting there, eventually!

[jjj]

Progress Report:
In the meantime I did some testing and discovered that connecting a cable to the 10K potentiometer in my Yamaha's MFC10 Midi-Foot controller allows me to operate this foot controller's circuitry via an LDR on the 120-button box. The LDR with a yellow-green LED is surprisingly fast, because the foot pedal's circuitry works via MIDI (!!)

My initial idea was to place the whole bass section onto soft springs, but then I discovered that every time I change to another chord position, my hand won't press the box and the volume will decrease considerably. To firmly control the box movements a leather strap or ridgid bar has to hold the hand onto the box. That's why accordions have a leather strap on the bass side.

The idea of tilting the unit slightly forward/ backwards doesn't work either, for only up & down hand movements are fast enough for bellow shake and tremolo.
Yes, as you see ...I'm getting there, eventually!

[jjj]

Well, it seems... I have gotten there, already!
Here are some sound examples of my new 120-button accordion MIDI + with its Vol-Controller connected via MIDI to my Yamaha Tyros3:

I uploaded them, here: https://app.box.com/s/ndkzvzlj1zpzb0qlj4g4

1= Tyros3 accompaniment only without my Vol- Controller
2= Tyros3 with my accordion MIDI + with (!!) its Vol- Controller
3= Tyros3 accompaniment only without my Vol- Controller
4= Tyros 3 with my accordion MIDI + with (!!) its Vol- Controller
5= Only my accordion MIDI + with its Vol- Controller connected to Tyros3
6= Only my accordion MIDI + with its Vol- Controller manually played
7= Only Tyros Kbd sounds with my accordion Vol- Controller
8= Some bellow shake samples...

Result: I reckon the rhythmic volume fluctuations of the 120-button accordion bass MIDI + with its Vol-Controller adds expression to the melody and make it sound far more realistic and lively. Without this expression the melody sounds... "rather emotionally poor and almost boring!"

Secondly, the irregular/ random bass and chord injections of the 120-button accordion MIDI bass section makes the automatic Yamaha styles accompaniment sound richer and less automatic or more natural.

Last ...not least, the advantage of playing the Tyros3 or any MIDI-Synth via the 120-button accordion MIDI bass section accompaniment only seasoned accordion players know to appreciate.

Note: I'm not too sure if my Vol-Controller is really able to produce that authentic accordion's bellow shake, albeit it sounds pretty close and requires some practice, because the bellow shake is rhythmically applied.
At least for now, its effective volume and tremolo variations are able to significantly enrich the melody.

Conclusion:
Musically viewed, my project brought me a huge step nearer to what I enjoyed on the accordion. It feels like having over night acquired 5+ years of practice!!

Thus, this easily adaptable project opens new musical opportunities to accordion players, for now they are able to extent and effectively apply their skills to great many MIDI instruments and workstations, such as the Yamaha Tyros etc. of their choice; i.e not limited to a specific make.
Roland accordions: In my opinion, technically the pricey Roland MIDI accordion is great, but I happen to prefer the Yamaha sounds.
Since many accordion players might have difficulties to construct my project, it might be a good idea for someone to manufacture and sell it for under $600.

Hence, my next and probably last Tyros project will be constructing the 4-row (removable) JANKO Kbd layout on top of the Tyros' zebra piano Kbd.

Result: That will enable me to play all major and minor scales, without having to put up with many years of practicing the irregular zebra piano Kbd.

To promote and perpetuate the irregular zebra Kbd is only OK for music teacher's profits and helps professional musicians to discriminate themselves from hobby musicians. Their motto is: "Why make it easy, when it can be made complicated!"
I am rather interested in simplicity! Thanks to my bit of practice in playing the accordion, I gained some basic insight into music theory, which enables me to simplify the lot, incl. the music notation.
The end result will be: having created the easiest and fastest method to learn and play modern Synths!!
It means a lot to me, because musical sounds and harmonies happen to be a major part of my life's enjoyment. That's why football and other emotionally poor, non-creative hobbies, such as gambling, drugs, motor bikes etc. are meaningless to me...
Yes, I'm into "philosophical pondering" and writing, as well. That's why I believe that only by discovering and fulfilling our (inherited, positive mental, emotional and physical default values) mission, we will be truly able to enjoy our life to the fullest!

[jjj]

Progress Report:
Since "Help yourself so, helps you God!"... seems to be the motto in this forum as well, I struggled myself to some acceptable result, in regard to the emulation of the accordion "bellow shake" effect:
Instead of trying to create this effect via LDR -LED Vol control, I explored the Yamaha Tyros3 DSP effects and found "something similar" to a bellow shake effect, by applying its "Tempo Echo Delay". The settings on the Tyros3: I'm using Part Left for the 120-button accordion bass and Part RIGHT with any accordion for the melody.
1) Part LEFT > Accordion Bass > Voice Set > Effect/EQ // Rev:30 // DSP: ON // Depth:42 > DSP Delay > Tempo Echo: ON // Value: 8th > Save
2) Part RIGHT > Accordion Treble
This settings creates a kind of bouncing effect, which seems to sound pretty close the accordion bellow shake. Its intensity and echo length is as well adjustable. Yet, each beat needs to be reactivated and this automatically varies the effect's speed.
The great thing is that this effect setting can be Mem activated by pressing only one push-button!
Here's a recording of how it sounds:

[jjj]

Today I discovered that the DSP setting of Rev: 77 and its Depth: 65 produces an even better chopper or bellow shake effect. I don't think there's much more I can to improve on that. Of course with an accordion bellow one can manually vary the bellow shakes, whereas using the DSP effects for it, this is not possible, unless it would be possible to vary its length via LDR-LED control. Chances are that there are some Time Echo pedals available...?
Then I could apply one of them for this purpose.
Here's how the DSP effect of it sounds now:

[jjj]

I just discovered that $200 "HOT Hand 3" audio volume (etc.) controller. I think that could get me progressing... to better bellow shakes.
I suppose its built around that "MMA7660FC" chip or similar.
My electronics hobby knowledge as to work out how this chip could control the brightness of a LED.
Because, if I knew that I could easily control the LDR, I soldered in parallel with my Yamaha foot controller's 10k Pot.
Is that very complex? If not, please kick me in the direction to help myself...
Thank you in advance.

[jjj]

How about using a tiny mercury glass switch, found in Chinese "Driver Anti-Sleep" devices, here: Car Driver Safe Device Anti Sleep Keep Awake No Doze Nap Drowsy Alarm Alert | eBay I have a couple of these. Of course, they only turn on and off, but that might be good enough to swing audio volume up and down or not? At least the liquid mercury allows me to shake-switch and so, vary the turn on & turn off events via lateral hand movements.

Of course the volume should not just abruptly turn on or off, but rather permit varied, smooth volume swings.
I'm thinking of a simple circuit, based on an electrolytic, which softens and briefly delays the mercury switch's turn on and turn off events.?

That way I could build it into a tiny box and attach it to a ring on my finger.
This would allow me to rapidly shake the mercury switch horizontally and thus, create the desired volume and tremolo variations.[/u]