help me modify the Thing Modulator

[emiuaeiiua]

ive been working on the thing modulator schematic from the circuit snippets page... and its working fine. sounds great before some distortion circuits for me... also sounds good having a switch to change the 100k resistor before the freq. pot to 200k for some extra low squarewave slop in the feedback loop.  

but im interested in building an lfo or some kind of sequencer for it. being of little knoweledge to this stuff i dont think what i have in mind is possible...
either a simple lfo like the opamp based one in the schematics here or maybe even my little 4017 based ten step sequencer changing the value of the frequency pot on the lmc567 pin 5 and 6.  

also would a cap to ground on the output create that low pass filter that id need to help with the squarewaves clicking on the lower frequencies? would make some horrible sub bass abnormal drone if only the clicks would fucking stop!

thanks,
joshua

[expanoncolin]

Try a .01uf cap to ground or a .1uf cap to ground.  The .1uf will be a LOT of high end loss if that's what you want.

For the LFO, try wiring up the LFO in the tremulus lune (just because I'm on a relaxation oscillator trip):

Basically the bottom two boxes.  Then optocouple the LED to an LDR in series with the frequency potentiometer and you've got it.  You can omit the fine pot if you want, and if you don't want the spacing knob just put a 470k resistor instead of the pot and the 220k resistor.

Good luck!

-Colin

[guitarhack]

hello,
fellow noise fiends!

fun lil' circuit, the thing modulator!
great idea with the lfo.
 I put one in an old dearmond volume pedal to control the freq.
 took alot of practice but you can rock the pedal, changing the carrier to follow the pitch of the instrument. I used a linear pot to try and keep the sweep of the oscilator pitch even from zero resistance to full.

Also, you can take the signal from pin 3 (input) wire it to a spst toggle then to a variable resist and then to the out (pin 2) after the cap.
 use the variable resister to mix in some dry signal for "wild leads" or what ever. and just flip the switch to get back to full on modulation.

looking at my notes I see that I tied pins 1 & 8 together and to ground.  why? I don't know!
what good are notes if you don't write everything down?

also if you use bypass switching with this you will need to use shielded cable for both the input and output jacks. and you still might hear the oscillator doing its thing.

man, I forgot how cool this chip is! check out the pinout and the sample circuits here, they have both versions lm & lmc :http://www.qsl.net/df7tv/k2_semi.html
I'm gonna try to abuse that vco!
-matthias

[marmora]

Try a .01uf cap to ground or a .1uf cap to ground.  The .1uf will be a LOT of high end loss if that's what you want.

For the LFO, try wiring up the LFO in the tremulus lune (just because I'm on a relaxation oscillator trip):

Basically the bottom two boxes.  Then optocouple the LED to an LDR in series with the frequency potentiometer and you've got it.  You can omit the fine pot if you want, and if you don't want the spacing knob just put a 470k resistor instead of the pot and the 220k resistor.

Good luck!

-Colin

I finally got around to trying Colin's suggestion.  I built the Thing Mod on breadboard before, so I knew what it would sound like on its own. The LFO adds some very interesting sounds to the Thing Modulator.  It can vary from wavering, to throbbing dance sounds, to twisted circus music and the guitar signal fighting the LFO.
Some quirks include being able to hear the carrier signal in bypass.
I tried the resistor and LED trick:
http://experimentalistsanonymous.com/board/index.php?topic=1809.0
but I still hear the it.
The other strange thing is that when the LFO is going really fast the bypass LED blinks in opposition to the LFO LED.  Strange since I wired it up true-bypass.  It's weird, but also kind of cool/helpful.

Thanks for the tip Colin!

[mikebike]

that sounds cool, blinking leds!

i still hear the carier in bypass too, ill try shielded wire.
 i hear you should only conect the shield to one side not both.
any insight?

heres a shot of mine, i found a few of these awesome old lamp covers and hot glued an extra bright led in there.

sorry about the crappy cell pic

[marmora]

Looks awesome!
Yes, for shielded wire, only one side of each ground cable should be connected.
I know there's a project involving some guys from circuitworkshop.com and maybe another forum where they came up with some mods to the Thing Mod to quiet it down.  I think they called it the Logan 5.