Looking for ideas on this project

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Hey everybody,
I'm new to this board, and glancing around it you guys know a helluva lot more about electronics than I do. My background is fixing/building guitars and other string instruments. I'm good enough with electronics to wire them up pretty well.
I want to modify one of my instruments. It's a double neck homemade electric lap steel made out of a large oak board. I put it on a 4' stand and it looks like a Dr. Seuss instrument. It's wired up for regular double-neck switching, as well as with another input and another switch, so I can run my electric guitar through it and then run either instrument out to my amp.
Originally I wanted to install a theremin into this thing. I still have a good 4" x 18" of unused space in the wood, into which I could recess some electronics, add an antenna or two, and make it look even crazier (as well as capable of making wild sounds). Someone at thereminworld.com told me I wouldn't be able to do that, as the metal strings would interact with the antenna's field. If anyone knows whether he's right or not, I'd appreciate any advice. But the main reason why I came here follows:
Someone else on that board suggested I try to install a ribbon controller instead of a theremin. I think that would be awesome. I don't really know much about how they work, though. Even assuming I could build one myself, wouldn't I need to get a MIDI box or something to control with it?
My onstage setup is already quite complex and there are wires all over the place. Is there a simple way I could wire up the controller so it produces a sound (just one dumb old sound is enough for me) without adding a ridiculous amount of gear to my setup, or go over my budget (I don't wanna spend more than $300 on this)?

I'm also open to other ideas on what to install into my steel. I'm in a funky redneck rock band and there's ample opportunity to use a wacky sound in lots of our tunes. Thanks a lot for your help guys, I'm really eager to get started on this so ANY advice is appreciated.

Max
 
In fact there is a simple theremin-like circuit that costs nothing and makes a simple square-wave sound. It is listed in a strange site... maybe I'll search....

http://www.geocities.com/tpe123/folkurban/synthstick/synthstick.html

I found it! Here it is....

It looks easy to build, no MIDI or strange things, costs nothing, sounds (quasi) acceptable. It can be built on perfboard, if you have some basic layout and soldering tips (but you have it if you can wire a double-neck strange sort of thing).

Hell, you can even use it in combination with steel strings ('cause it's only sensible to touch), maybe on the fretboard of one of the necks of your lap steel.... :bigeyes:

Also if you don't like the sound you can always mod it to trigger a midi module... but that's another story....
 
giame-

I've been trying to get in touch with the author of that page but no luck so far. I'm wondering what the range of this thing is. In his sound file, he plays such a simple two note techno beat, I can't tell whether it's incapable of anything else, or if the guy who made it just isn't all that creative with his sound files...

Say hi to Venezia and your beautiful country for me, I was there about three years ago for part of my year abroad (which I spent mostly a Firenze).

Max
 
Hello MaxGuitar! Thanks for the place where I live.

Yes, the author of that site is uncontactable (is this the correct term?). The range of that thing can be varied by:

- differend lenght, width and material of the video tape;
- a simple fixed resistor in series with that or in parallel;
- maybe changing that capacitor indicated in the schematics;

It will be more useful (IMHO) if someone able could design a sine-wave type of oscillator, that would be connected to our stompboxes to distort it in every way we like. With square waves you can't do much, at least when (like in this case) you have no control over the armonics, the pulse width, ecc...

Maybe running two of these, one exactly one octave higher than the other, or some other strange interval...

Sorry, but I'm not so experienced in synths, I know only about treating our guitar's signal (in every POSSIBLE ways :D)!
 
Hi there guys.
This sounds fascinating; I love the idea of using videotape for making ribon controllers (why don't I have good ideas like that?). Presumably the right kind of audio tape would work as well. Also, I can't help thinking that a second piece of magnetic tape could be used im place of the silvered Mylar - at the cost of doubling the resistance, of course. However, I guess that Mylar would be harder wearing and longer lasting, if you can get hold of it.

As requards the electronics, the Schmitt-trigger inverter oscillator is one I've used many times, mostly as a clock for logic circuits. It's nice and simple and capable of a decint frequency range. If you want other waveforms, if I where you I'd look at some of the function generator ICs that are available - typically giving sine, square, triangle and maybe sawtooth, controlled in frequency by a R/C cobmination, just like this circuit. Building sine wave oscillators is, I have heard, rather tricky (plus they sound pretty dull). I suspect that using valves would also be making life hard for yourself, plus using far more space/power than ICs.

Pretty much anything could be controlled from these videotape ribbon controllers, I wonder if filter(s) might be of interest - either for the output of the guitar or the oscillator? Once more, chips are available which contain most of the bits you need to make a fully-paramatric (cuttoff, boot/cut and Q) filter.
Also, depending upon what you want to controll and how complicated you want to make it, you could include a sample-and-hold circuit so that the ribon comtroler holds its value when you take your finger off?

Anyway, keep us up to date with this fascinating and mildly crazy project!
TOMi.
 
Hey guys, thought they posted my last one but I guess it got lost.

I really want to start on this project and I wanted to ask you where the best place to buy the parts is. I see a bunch on the internet but don't know if there's any one best to go for. They're all so cheap that the decision feels too easy.

Tomi- you're saying that I can just substitute a function generator IC for the Schmitt trigger IC and the stick will give me a different tone? Could you be more specific as to which one I need, as I am totally stupid in the electronics realm and will probably buy the function generator IC for a vacuum cleaner by accident (go ahead and laugh).

I'm gonna order these parts as soon as I can get it together, and buy enough that I can experiment a bit. thanks for all the help dudes.

Max
 
Ok guys, I ordered all the parts from mouser. they should get here soon.
While I knew the values, I had no idea what variety of capacitor I should use... they were so cheap that I got a ton of different values and materials... ceramic, film, polyester, etc. I'll try to create a setup where I can easily interchange the caps to see if there's any difference in the sound output.
I'll let you guys know when the parts arrive.
 
Alright, the stuff is here!

How in the world do you wire a circuit up to such a tiny microchip??? This thing is like 1/4" by 1/2" and it has 14 pins coming out of it! Can you just use a regular soldering iron?

Guess I'll get to work on my accuracy. I would just worry that it would be really easy to fry the chip.

Any advice? thanks.

max
 
get out that 100W iron j/k

A temp controlled solder station would be a good start, some can be had for dirt cheap prices. A micro fine tip of say 1/16" either conical or screwdriver shape. A straight iron of 30 watts is good. With inter-changeable tips are the boss. Make sure you tin the tip before it gets to hot, on first time running. A swing o lamp with a magnifier built in is a must.

I like using ic sockets for prototypes. As for soldering: the IC generally can take an iron tip on a single pin for 10 seconds. Any longer than that you are going to be living on the edge.

63/37 solder is the best, 60/40 is acceptable and solder must be resin core.

Lastly, soldering is a fine art. you'll love tacking on little SMD's.
 
If you have never soldered on a pc board before, consider building a simple kit first to get some practice. There are many small simple kits involving a chip or two. SOme blink lights and others make noises, but for a few dollars you can get something and get some practice doing the work. That is better than damaging your real project.
 
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