wicked chip

[Ansil]

http://www.qsl.net/wb9ajz/laser/data/opt101.pdf

[smoguzbenjamin]

Cool, you could use that for a light-dependant wah or tremolo or something "Wave your foot over the pedal to make cool sounds!" :mrgreen:

[Mike Burgundy]

methinks light-dependant Theremin... Cool
Plus the chips themselves look radical, ofcourse.

[smoguzbenjamin]

I've been pretending to know what a theremin is for a while now. I give up, what's a theremin?

[ExpAnonColin]

Only THE coolest instrument EVER!

This is probably the best site: http://home.att.net/~theremin1/

-Colin

[Peter Snowberg]

http://www.thereminworld.com/

A Theremin is an instrument that uses two antennas for input. The distance from your hands to one antenna controls pitch of and oscillator and the other antenna controls volume.

They're named after their Russian inventor, Leon Theremin. A friend of mine met him and toured with him a little in 1992/3. He was actually touring at age 96 :shock: and passed away the next year. His daughter is a MASTER of the instrument and can play it with precision. The rest of us just fumble around and make "spooky" noises.

See the schematics at the link above and build one for yourself!

Take care,
-Peter

[ExpAnonColin]

Speaking of which:
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=2593311627&category=31456

-Colin

[idlefaction]

555 + LDR = theremin!  

i made a radiowave theremin once in a stompbox, when you stomp it in the guitar signal is muted and the theremin signal takes over - it had a normal guitar jack for the antenna input, and i had it set so if you didn't have anything plugged into the antenna input it rerouted your guitar as the antenna.  it was seriously fun to play with!  moving around and closer to your amp and moving your hands around your strings...  

[Nasse]

:oops: I usually just put some vibrato, legato and pbend on my Casio CZ-1000 whistle tone. And of course some huge outboard reverb :oops:

[ExpAnonColin]

555 + LDR = theremin!  

Booo!!

-Colin

[smoguzbenjamin]

Kewl :mrgreen:

555 + LDR = theremin!

How would you do that, Darren?

[Jason Stout]

Scroll down to optical theremin

555

Enjoy!

[smoguzbenjamin]

Cool! Give me a hand here on those values, check out www.geocities.com/smoguzbenjamin

[ExpAnonColin]

I'm suprised at that "Triangle type output" from the 555.

-Colin

[troubledtom]

Scroll down to optical theremin

555

Enjoy!

nice pdf link
     cool thanx,
            - tom

[Jason Stout]

You can try
0.01uF for the comp cap
0.1uF X2 for the freq caps (experiment!)
330 Ohms for led current limiter
I feel that you can get by without the series resistor before the cap going into the 741's noninverting input; you can make that cap 10uF, or just make it more than 0.5uF
Remove the feedback resistor, Keep the feedback path! This will give unity gain.
Make the output coupling cap big, like the input coupling cap.
Until you get it running, replace the output volume ldr and resistors with a pot, this will simplify things. Output should be taken from pot wiper (like most stompboxes).

BIAS THE OPAMP!

Have fun!  :wink:

[Jason Stout]

I'm suprised at that "Triangle type output" from the 555

You will find that across the timing caps in 555 circuits. Using it is the harder part.

[mattv]

Re: triangle output

Check out Small Bear's Tremulus Bear for a nice way to manipulate the triangle.