Vactrol chiptune squarewave osc (w/ audio and schematic)

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Tombola
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Vactrol chiptune squarewave osc (w/ audio and schematic)

Post by Tombola »

13 components, based on hex schmitt trigger, lives up to its name.
Will post schem and audio...
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J3RK
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Post by J3RK »

I'd love to see these!
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gde
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Post by gde »

it has an interesting proximity to the quantizer....
LOL
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falafelbiels
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Post by falafelbiels »

Audio or it just barely exists...
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falafelbiels
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Re: Vactrol chiptune squarewave osc

Post by falafelbiels »

Tombola wrote: Will post schem and audio...
falafelbiels wrote:Audio or it just barely exists...
Whoops, sorry bout that.....
patience is not a virtue of mine so much that I don't take the time to read on these here forums. I just watch the pretty pictures and shout a lot.
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Post by Jarno »

falafelbiels wrote:...and shout a lot.
Confirming the public opinion on people from your particular city. :mrgreen:
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falafelbiels
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Post by falafelbiels »

FEYENOORD! HOOLIGANS!
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Post by Pfurmel »

This looks very promising indeed
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Tombola
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Post by Tombola »

gde wrote:it has an interesting proximity to the quantizer....
It definitely DOESN'T track 1v/oct!
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Tombola
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Post by Tombola »

Here's the schematic and a pic, including very chic black electrical tape vactrol. It has one LED and two LDRs. I used different brands of LDR to make the second osc track differently from the first.

In this rather poor demo, the first sound is a good oscillator (RS-95e) to give an idea of the random CV going into the osc. It then switches to the bad oscillator. The notes explain what's going on

http://soundcloud.com/musicthing/bad-osc-test

http://soundcloud.com/musicthing/bad-osc-test

Image

Image
DIY vactrol oscillator by Tom.Whitwell, on Flickr
Last edited by Tombola on Thu May 05, 2011 10:23 am, edited 2 times in total.
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falafelbiels
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Post by falafelbiels »

Very... Cool...

Even without audio...
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Post by iopop »

Lovely!

Thanx for posting the schema.
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Post by CLee »

very cool. I'm just starting to mess around with Vactrols... they are very strange beasts indeed.

I don't know if I'm totally following what the switch does.
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Tombola
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Post by Tombola »

CLee wrote:I don't know if I'm totally following what the switch does.
The 40106 is six squarewave oscs in a chip. I'm using two, each tuned by a separate LDR. One LED shines on both LDRs.

One osc goes to the output, via resistor.

The second osc goes to the switch. Three possible states are:

OFF - only the first osc sounds

Down - the second osc goes to the output via a resistor, so is essentially mixed with the first osc. You hear two distinct tones.

Up - the second osc goes to the output via a diode, which means it influences the first osc in strange ring-mod ish ways. At low frequencies, it sort of pulses the other osc on and off.

I should really build a version with all six oscs going and a big bank of switches.
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Post by Pfurmel »

I can't wait to hear this thing, cool design.
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falafelbiels
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Post by falafelbiels »

And with audio still very cool... It's a cool thing! Great project for next Monday's soldering workshop, thanks man :party:
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Post by Rod Serling Fan Club »

Tombola wrote: I should really build a version with all six oscs going and a big bank of switches.
That could be interesting. Something similar to the Cloud Generator with spread for each osc (if possible?) but in lo-fi square wave form could be a very fun noise maker.
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Post by Jarno »

falafelbiels wrote:FEYENOORD! HOOLIGANS!
ROFL!
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Post by SMS303 »

falafelbiels wrote:And with audio still very cool... It's a cool thing! Great project for next Monday's soldering workshop, thanks man :party:
okay i allready know what we will do next monday :tu:
Jarno wrote:
falafelbiels wrote:FEYENOORD! HOOLIGANS!
ROFL!
da kannie hé!
jij bent geimporteerd uit Braboland :help:
------------> Jaime Murray does Capua...... ------------------------------------------>
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Post by fengland »

I like the slew on the pitch change. sweet.
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Post by JP »

Someone needs to make a pcb for this insanity.
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Post by ringstone »

40106 / 14584 square wave oscs (6 detuned for a complex metallic waveform) are pretty much in every 808/606 type hihat/cymbal voice... and also 808 cowbell :)
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Post by lazerkind »

Nice, what kind of LDR's are you using?
There are many different ranges of LDR's to choose from so just a hint of min/max resistance would be great.
//L
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Post by Tombola »

lazerkind wrote:Nice, what kind of LDR's are you using?
I literally pulled a couple at random from a bunch I ordered from Banzai. I don't think it's that critical, as the module really doesn't track with any accuracy. As I said above, I'd probably get a roughly matching pair if I was doing it again.

I'd also probably put slightly bigger caps in the oscillators - in use, it kind of crashes at the bottom end (I assume when LED drops out as the voltage goes below 1.5v) - which is quite a cool effect, but makes it harder to use the oscillator for bass, while there's a lot of more controllable range higher up that I'm less likely to use.
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Post by falafelbiels »

Hey I made this at solder workshop tonight and it is really cool sounding, espacially the "ring" type effect. Casper was about to give up on this, but when he heard it, he decided to definitely finish it next week. Must be a cool thing then, eh?
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