Unlocking the Yamaha E70

[Guest]

Orr, instead of using digital pots, apply variable voltages to the pins in the E-30/50/70, which is likely a better route.

Hmmm.... voltage control of the voltage producing sliders? Might be a bit of a recursive exercise? ; )

You can always add in the fancy controller stuff later on, otherwise, you'll likely learn a lot more about how to make that work in a practical fashion by carrying out your present build/plans. Once you start adding electronics into the mix, you'll have a lot more technical issues to deal with!

One idea I had was taking one of those consumer midi keyboards with the LED per key and adapting it to the organ. In theory, the lights come on exactly as long as you hold down the note - add a switch/gate between that and the corresponding organ key/contact and you have a two way MIDI interface. They do sell kits that adapt organ keys to midi, but I don't know that they do the opposite, plus they don't seem to follow the Yamaha standard for keyscanner....

More food for thought!

[mseven]

Arduino Into The E-50

Keyman! Ok it took awhile, but I figured something out...

Hmmm.... voltage control of the voltage producing sliders? Might be a bit of a recursive exercise? ; ) More food for thought!

<a target="http://imageshack.com/a/img809/9737/egbl.jpg" href="http://imageshack.com/a/img809/9737/egbl.jpg"><img style="float:right;margin-left:40px;width:600px;border:1px solid black;" src="http://imageshack.com/a/img809/9737/egbl.jpg"></A><a target="http://imageshack.com/a/img189/8162/28b7.jpg" href="http://imageshack.com/a/img189/8162/28b7.jpg"><img style="float:right;margin-top:20px;margin-left:40px;width:600px;border:0px solid black;" src="http://imageshack.com/a/img189/8162/28b7.jpg"></A><P>Sounds like a runaway resonance feedback to infinity.. should give me just the effects I want </P><P><B>But alas! I believe this mystery is solved...!</B> Everything had to get jumbled together and shaken for a while. But I think it's ready for presenting and assembly.</P><P>The header pins on the left board will be connected to the slide pots by wires, soldered on both ends. The board will be lightly mounted on the slat that protects the slide pot pins and holds the pots firmly in place. The wires can be four or five inches long to give enough room to work should a pot need replacing. So there will be zero strain on wires in this area, as everyone suggested should be the case.</P><P>The board on the right will also be pretty sparse - no components - and it will be wired into the organ a la Mr. Brasse's Son of GX (although I've noted the pin differences for the E-50). Boards made to plug into an Arduino are generally called Shields.</P><P>Pictured below we have a genuine Arduino MEGA 2560; it has amazing specs...

<a target="http://imageshack.com/a/img812/6746/b0yf.jpg" href="http://imageshack.com/a/img812/6746/b0yf.jpg"><img style="margin-right:0px;width:200px;border:1px solid gray;padding:10px;" src="http://imageshack.com/a/img812/6746/b0yf.jpg"></A>

... enough analog inputs, and PWmodulatable outputs with only a couple to spare. The PWM outputs, although digitally produced, act like an analog voltage level.</P><P>So when the three boards are stacked (Arduino on last) the slide pots will go into 13 of the Arduino analog inputs. The Arduino PWM outputs will simply (at first) send out the varying voltages to the Electone, likely via op amps to match the 10 and 15 volts required inside the Electone. Then the fun begins...</P><P>Adding a basic LFO is about the easiest thing imaginable at this point. Its about 2 lines of code on the Arduino. And to which Electone variables should a modulation be applied? ... again, assigning the LFO to a pin can not possibly get any easier! Whether to stack the modulation on top of the slider value, or superimpose it... can do either or both. How about more complex waves... sawtooth, square, a combination? Add noise? Everything from here is just programming.... What about several different LFOs... I would guess 16 MHz clock speed can handle that.. How about storing favorite slider settings into a memory card using the Arduino. All very straightforward at that point once that little computer is stuck in there... Adding the midi interface into the mix wouldn't be too hard I think?! And more lights... yes needs more lights!</P>

[Guest]

Seems like you've got a practical solution, should get you over the hump in any case.

Whatever happened to those neat little modulation boards you were going to tie in, did you not pick some up? They're basically the arduino already programmed? they seemed pretty good? Otherwise you can certainly DIY if you're looking to do a little more hands-on programming and such.... reminds me when I wanted to build a key scanner for my C64 and a cheap intellivision (or some such brand) keyboard. I had in mind how to do it, lo and behold the next C64 magazine I came across had the exact design idea and the machine code program to boot... getting all those magnets and reed switches to work together was painful... funny I'd never realized until years latter that something seemingly klunky as a hot glue gun would have worked wonders!

I like the arduino stuff in any case, apparently much easier to work with than PIC... one day!

[mseven]

The Electric Druid VCLFO (http://bit.ly/18AIt99) looks great and I did get three of the PICs, but in comparison to an Arduino..? Well I think in this application there is no area that the a microcontroller won't surpass a lone PIC chip, especially if the MC has 70 inputs and outputs and runs at 16MHz! Well ok yep, other than the PIC is already programmed.. Also it was good fortune to find the Arduino connector protocol offers a great solution to the Son of GX wiring tasks, especially considering the peripherals etc in this build.

I see the Arduino as basically a PIC surrounded by all the things needed, beginning at code level to make it actually usable! And they don't really need all those physical peripherals or the board itself of the MEGA or others. I'm working on things that use the ATTiny85, just a little 8-pin dip.

Seems like you've got a practical solution, should get you over the hump in any case.

Whatever happened to those neat little modulation boards you were going to tie in, did you not pick some up? They're basically the arduino already programmed? they seemed pretty good? Otherwise you can certainly DIY if you're looking to do a little more hands-on programming and such.... reminds me when I wanted to build a key scanner for my C64 and a cheap intellivision (or some such brand) keyboard. I had in mind how to do it, lo and behold the next C64 magazine I came across had the exact design idea and the machine code program to boot... getting all those magnets and reed switches to work together was painful... funny I'd never realized until years latter that something seemingly klunky as a hot glue gun would have worked wonders!

I like the arduino stuff in any case, apparently much easier to work with than PIC... one day!

[Guest]

If programming/interfacing is your specialty or hobby, then by all means...like you said, the Druid chips have all the work done for you? It's one thing to add modulation etc., but it would be a huge plus if you could take on those previous ideas of keyscanning/midi interfacing - you would be getting a lot of business from all the electone owners.... food for thought!

[tekkie]

I am interested in selling a Yamaha e-70, I researched and found this site and some people who mod to make it into a synthesizer. Does anyone have interest in picking up the organ at their expense in a South Carolina Home?

[Guest]

- - - Updated - - -

As for modifications of E50, as you remember I was working on MIDI interface for E-series, but it is going very slowly as recently I can't get myself to do any electronics work, don't know why . I was thinking of best way to interface modern microcontroller (that works with TTL levels - 0-5V) with rest of organ, that uses negative voltage (-15V) as its logic "1". First I was drawing some transistor/opamp/diode level shifters, but recently I realized that the optocouplers are the way to go.

Looking at it, myself, from what I could tell, you just apply the digital ground to the -12V and invert your logic (if needed)?

[mseven]

I am interested in selling a Yamaha e-70, I researched and found this site and some people who mod to make it into a synthesizer. Does anyone have interest in picking up the organ at their expense in a South Carolina Home?

Thanks for the offer... too far for me. Otherwise I'd be over there pretty quick!

- - - Updated - - -

Looking at it, myself, from what I could tell, you just apply the digital ground to the -12V and invert your logic (if needed)?

Adamstan was a great contributor way back when, but thinking his solution is too complicated, as you say.

Maybe even just a voltage dividing resistor setup..

[Europanaut]

Needless to say, owning an E70, and living less than a two hour drive from mseven......I'm watching this progress very carefully.

[mikewalter]

[Guest]

Wow, I guess we all assumed that the basic functional review had been done with just the electronics to sort through.... well better late than never!

[mseven]

Hey! I was chatting tonight with one of MakerSpace's laser cutting experts. He metnioned an important tip when laser cutting things like lettering with a line width - for example as in our case of emulating the original Yamaha lettering - of about 2 mm.. use raster, not vector. Vector needs the programmer to manage the many different lines to make up the full width of the line, while raster manages it all by itself. Sometime pretty soon I'll take a board down there and get some help burning the lettering into a test panel. In the meantime, I've been arduinoing like crazy. It's another revolution!

[Guest]

The Laser lettering should turn out very nicely - I recall that all the little segments, especially curves that generate a ton of segments - raster is simple, as a small area. The Arduino reference sounds interesting, just general exploration, or thinking down the road for your organ interface projects?

[mseven]

Arduino reference... just general exploration, or thinking down the road for your organ interface projects?

Always thinking down the road!

====== Another E-Series Controller comes into focus

Turns out our new 3D printer prints flexible material. So it looks like it can print the missing "pokers" that push down on the ribbon on the upper manual of E-series keyboards - those pokers that are missing from what appears to be the North American models. The opto-coupler could then modulate well, at this point, any of the 13 characteristics of the E-Series Electone sound characteristics. But that is pretty far down the road!

[Guest]

Always thinking down the road!

====== Another E-Series Controller comes into focus

Turns out our new 3D printer prints flexible material. So it looks like it can print the missing "pokers" that push down on the ribbon on the upper manual of E-series keyboards - those pokers that are missing from what appears to be the North American models. The opto-coupler could then modulate well, at this point, any of the 13 characteristics of the E-Series Electone sound characteristics. But that is pretty far down the road!

Ahhh, yes, the thingamajigs that act on the shutter which controls the vibrato - yeah, that could be adapted towards modifying a number of parameters. I think the circuit is setup to transmit more of a varying signal as opposed to a constant 'pressure', and it's optimized for monophonic control whereby if you hold down one note that is applying pressure to the 'ribbon' it's going to be difficult to have another shifting key move it.

In contrast, it's been mentioned before, but the CS-80 has a force sensor under each key, and then circuitry to make sure it gets assigned to the same voice circuit as the one playing that note (polyphonic after-touch).

B.T.W. Since you have the D-85, you could put a resistive ribbon type strip on it to control things like pitch, vibrato, tremolo, cut-off and resonance in parallel with the existing controls of the Solo Synth.