Help me build Buchla/Serge style Capacitance Touch Keyboard?

[Photon]

[mono-poly]

Interested.

[creatorlars]

I'm interested as well.

[boosimas johnson]

it would be a challenge for me to be disinterested

[Coriolis]

[akrearke]

yeah, i'm not trying to make a living on this, but to bring in some cash to help with the cost of building the rest of my b clone system.

[akrearke]

I thank everyone on this thread for being so patient. I have just completed the last 5 circuits for my buchla clone system. I have used many of the designs that have been posted here on electro-music and would also like to thank everyone who contribute freely. The modules I have built are Verbos's 258 in a dual, his 291 in a dual, and the 292 in dual, I have a dual 110, serge vca, and vactrol cross fader, also Topp's 281 in quad form that a I had to layout using the images from the pcb he offered sometime back, and the big one, the 112 Tkb. All that is left is the building of the cabinet and panel for the first part of this system. I wanted to have some modules ready that could be used to demonstrate the TKB. This is the reason for not posting any information., but it is my hope in the next month all will be completed. Then I will post all the information on this thread. In the meantime, I have done a double sided layout for the serge style TKB from the schmatic found on the music machines site, this is the one with the sequencing and whatnot. I'm sure everyone here is familiar with. I will also build a prototype of this as soon as I find an MM74C150, and will keep everyone posted as to it's progress.
Sometime in the next week I will go ahead and post the foil and parts layout for the Synapse article TKB. There may be some bug in this one, i will leave it up to others to find the problems and post there results, if any. Originally it was designed for 25 note operation, but I will trim it back to 16 since this seems to be the desired number of "keys". Again, thanks for your patience and I hope to have all this up very soon.

[Inventor]

Hi folks, I just noticed this thread and read some of the early posts. I really like the way that folks are sharing information about the subject, so I thought I would add my own contribution. Here goes:

One day a while back I decided I wanted to build a simple Theramin out of a relaxation oscillator and a capacitive touch switch. It ended up sensing my finger at a distance of a few centimeters, but it seemed to really work best when I touched the sensor with my finger. The more pressure I touched with, the faster the oscillator oscillated.

I have long since lost the design values, but they would be easy to come up with. The circuit consists of an opamp or comparator, three resistors, and the touch switch - that's it for each switch. The sensor plates replace the capacitor in the oscillator, very simple and produces a frequency modulated square wave output.

I also experimented with adding some circuitry between the sensor and the oscillator - I think I was using a negative impedance converter IIRC. I found that the NIC was not necessary, all you need is the relaxation oscilaltor I believe.

The attached photo shows how small and simple the circuit is.

I wonder if such a design would be appropriate for your purposes?

Les

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[bugbrand]

Hi akrearke

I've not looked through the TKB stuff really & don't know much at all about the 74series but.... Futurlec have the 74150 - I'd *guess* that'd be of use? (or are the technologies very different between different 74 classes?)

[ericcoleridge]

[akrearke]

The 74150 is, i think, supplied by a max. of +5V. the mm74c150 isup to 17v.
No i have not started vco calibration, I start the calibration and trimming after everything is assembled. It seems that the serge style tkb, is note on/off and preset cv only. it appears that it was primarily used as a sequencer.

[bugbrand]

Oh yes - you're right!....

It *may* be that the CD4067 would work though -- they have different pinouts, but appear very similar in operation. (well, I haven't fully checked the stats, but...)

There were two things I wondered about:
- the 4067 is bi-directional while the MM74C150 is one way -> but with the given setup this appears not to be an issue.
- the MM74C150 has a Strobe pin while the 4067 has an inhibit pin -> but this is, I think, basically the same -> Strobe is tied low and the Inhibit would also be.

.....Hmmm!?!....

[Randaleem]

[TekniK]

[Randaleem]

[Inventor]

Hi Randaleem,

I wonder, why not make some circuit board art out of those boards?

Les

[Scott Stites]

[akrearke]

I didn't make public the schematic. I just designed a PCB that will hold the parts together.

These ethical issues always come up when the word clone is mentioned. As a fan Ayn Rand, these types of questions arise in objectivist philosophy.
Stealing ones idea and putting it of as your own is wrong.
Taking ones idea and building off it and giving praise to the genius of that individual(s) that gave birth to it is sound.

People buy Serge/ Buchla systems because that's what they want and because they can afford to pay for them. I however can not afford them, had I the money I would gladly pay Serge/ Buchla for a system. I think those two designers have made the two coolest things since sliced bread.

There is now a debate about the use of words. Well, to be clear It is a direct clone of the the schematic on music machines. I don't think STS would be terribly worried by perhaps a handful of people who would build one themselves from the schematic. All I would be doing is helping them skip a step. I am not going to manufacture the board and sell it.

I think this may come down to an individual who is wanting to make some money. I am not interested in making money here, Save maybe enough to finish the rest of my system, and that by the japanese TKB. Buchla/ Serge are not going to lose money by having these foils published. But, you might.

Two points I would like to make 1) the synapse article was intended for DIY. 2) the Buchla 112 is no longer in production and the schematic is in public domain.
Since the Japanese version of the 112 is the one I cloned, (to be exact, which is clone of the 112, also a DIY project) I will post the foil and parts layout for this as well as make the PCB's available.
The other two will not be made by me for sale, but I would like to post the foils and layouts for these projects to get feedback from others.

There are I think many who would love to have these circuits for their own use, but cannot afford to buy them,and perhaps prefer DIY.

So, here is what I will do to try and make everyone happy.
I will post everything I have for the Buchla112/ Japanese TKB, and the Synapse TKB. I will not post the current serge model, it will probably not be of any use anyhow. But I will make one and if people have questions regarding this, I will answer.

Does that make everyone who gives a shit happy?

[akrearke]

Thanks for the Info Scott! Your right about the CD4051's, they could work, looking at the datasheets, but I didn't get enough from my digital fundamentals course to even begin to design the circuit around them. I know just enough to get an inkling on how the circuit works. But, maybe a recent member on this thread my find this useful in getting around the ethics of his own "clone" If there was anyone who offered the PCB's for these projects I would not have started making my own. It is a real pain in the ass. I spent most of my weekend perfecting the Serge layout and would have much rather been making music...
There has to be some other equivalent to the MM74C150, a drop in replacement. I'm still searching for a supplier...
In the meantime, I have a Lm3914 I would be willing to trade for MM74C150, if anyone has one. The LM3914 is used in Grant Richter's CV Twister and Optical Mixer.

[TekniK]

we all have to thank randaleem to have fucked up this project so now he don't have to be afraid for any competitor when he releases his TKB version because thats the only reason of his first comment.

BTW did u asked Don buchla permission to release the same style wooden cabinets u gonna offer?

[akrearke]

deleted due to errors

[Randaleem]

[TekniK]

If the relationship or deal is unclear between serge and rex,nobody knows who of both have the legal right to claim any royalties or give permission .

[akrearke]

I just wan to build shit man...
And "not being able to afford" something is a good reason to clone. I clone for myself, and if somebody else is in the same position I help them out where I can. The ethics issue; As i said before i agree that work should not be stolen. On the other hand, I didn't release the schematics. If some is one is that worried about their stuff be copied, then they don't post detailed information for the world to see. "There is nothing new under the sun" This old saying has always kept me humble. The fact that Serge would make a TKB when Buchla was doing it long before, is kind of copying someone else's work. The fact that all other synthesizer companies use a piano style keyboard is copying the original Moog work. If you play a style of music that is akin to another style, you are copying someone else's work. Everything we have is built off the work of someone else. Directly or indirectly. An anyone who claims any different is either delusional or super egotistical. Perhaps the greatest inventor that ever lived, Nikola Tesla, didn't even claim to have come up with his ideas on his own, and he shared the freely. We wouldn't have AC power were it not for him. Edison the thief Wanted everything to be DC, and HE DIDN"T INVENT THE LIGHTBULB. Deforest didn't invent radio. Man didn't invent fire. Invent is such an ugly word anyway, I prefer discover. The Principal that make things work were always there, someone just came along and discovered a means of generating and exploiting those principals.

[Randaleem]