The synthstick lives!

[Bill Bergman]

I was bored to day and decided to clean up my work bench. I found a circuit thats been laying there for a couple years. It was Tim Escobedo synhtstick. I had tried before to make the resistor ribon from VCR tape but I had the wrong kind. So today I thought I'd try a photo cell instead. I also had added the 2 caps .047 and .001 crossed on a 100k pot as kind of a mod. I wired it all up and plugged it into a Roland Microcube Amp and it worked :shock:  The mod not only controlled the pitch but more so kind of acts as a light sensitivity control. If I turn out the lights I can use the venition blinds to play music or put a tube over it and use a flashlite to control it.

As usually it's a Tim Escobedo project.... cool, unusual, and fun

[Marcos - Munky]

Cool, Bill. I will take a look in the Synthstick.

[Paul Marossy]

Is that circuit currently on Tim's site? It sounds interesting...

[Bill Bergman]

Here's the link  http://www.geocities.com/tpe123/folkurban/synthstick/synthstick.html

I have a pcb layout with the mod if your interested

[Paul Marossy]

Very interesting indeed. I'll have to read up on that a little more before I decide if I want to mess with it or not.

[Mark Hammer]

You're the adventurous type, Bill.  Given that the controller only needs to be the width of video tape, or maybe even decent audio tape (open reel, not cassette), it is hypothetically possible to make a polyphonic unit with 5 parallel controller ribbons - one per finger - and tune them to intervals with trimpots.  Kind of the ribbon controller version of the fretless bass.  

The simplicity of the circuit means you could pack a hex version and a mixer in a pair of 74C14's and a single op-amp.  Of course, guaranteeing linearity and maintenance of intervals as you press a few tape ribbons and slide up or down is another thing.

[D Wagner]

Hey Bill,

Is kind of a light dependent synth?  Almost an optical theremin?

I'd like to give it a shot.  I have all of the parts at home and my son loves noisy toys......  (The 555 optical theremin I breadboarded for him was too sensitive.  It would have freaked him out.)

Thanks,

Derek

datilderek( AT )excite( DOT )com

[bioark]

Here's the link  http://www.geocities.com/tpe123/folkurban/synthstick/synthstick.html

I have a pcb layout with the mod if your interested

i´m intersted

[spinoza]

I'm gonna try to build this too, just came home with all the parts required.

There's something I don't understand:


What are all the "s" symbols in triangles for?

[The Tone God]

What are all the "s" symbols in triangles for?

I belive Tim is trying to label the gates as being schmitt triggered. He may have not been able to label the IC gates with the same weird "S" symbol that you see in the schematic.

Andrew

[spinoza]

Oh and did I forget to say that THE SYNTH STICK IS !"(/$!($ AWESOME??

What? Haven't built one yet? Go make one. Now.

Oh and I remember people were trying to make it sound more guitar-esque. A simple way is to use higher voltage. Use 9v instead of 2x1.5v and you're good to go. I noticed that because I wanted it even more low-pitched, so I changed my battery strap for a 6v, and it worked perfectly. Took me about 15 min to do a prototype using alligator clips. Than maybe an hour to wire everything, find the right tape length, select the right "x" cap, etc.

It sounds very good. I wired the output jack so that the signal is stereo, useful to practice with headphones. I found out that the signal in each side is not exactly identical. There's a very subtle stereo chorus-like effect... awesome!! I'll probably add a body contact (or momentary switch) for the other hand to make the synth-playing is more realistic. I don't have a good "feel" from playing notes directly on the neck, plus the body contact would allow a bit of velocity control.

To be continued....

[Bernardduur]

Ah yes, I once build one too and still use it today;

I slighty changed mine; I use a "pen" (piece of metal) on a piece of wire as point B.

Got the idea by the video of Beach Boys' Good Vibrations

[goodrevdoc]

Yeah mine is great, but i could never get the simple LFO on the mods page at his site to work with the 40106. Haven't tried any other chips. Anybody got a good 40106 based LFO to try? I recall it sounding cool, but lots of noise and ticking...
-justin

[newperson]

i would like the pcb layout also.

[spinoza]

I use the 40106 and it's working perfectly. The "noise and ticking" is probably extremly low voltage coming into the chip resulting in 10-20hz square waves.

I have exactly this problem and I'm looking for a way to block any voltage below a certain limit (kinda like a gate, but for voltage), which would solve this.

I'm probably gonna make the Brian Wilson type stylophone when the pen next time. Much easier than my bass-synth.