Power stavring device - THE ELECTRON FLUCTUATOR

JingleJoe · Last edited by JingleJoe on Sat Jul 21, 2012 9:59 am; edited 1 time in total

Inspired by Uncle krunkus' device I have made a similar machine.
Attached is a very long sound sample of the first test (once I got it working properly) Things get most interesting in the second half.
Power starving is a much more versatile and interesting technique than I first thought!
I'll get a diagram of my circuit uploaded soon but for now a description should suffice because ti is very simple.

Two LFOs are passively summed/mixed with two resistors (one LFO rising/falling ramp with direction control and the other one, triangle waveform) then via a level control potentiometer they are connected to the base input resistor of a transistor inverter (like this one) the output of which is connected to the +V input of two chips: a 40106 used to make the oscillators and a 4070 EXOR gate which conbines the oscillator signals.
The output is taken through a volume control but other than that, directly from the 4070!

power starving test long.mp3

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best bit is around half way, there's also steam train sounds near the end :D

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power starving test long.mp3

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JingleJoe · Posted: Sat Jul 21, 2012 9:58 am Post subject:

I have named this device: Electron Fluctuator!
Find attached schematics and more demonstrations (but this time shorter).

electron fluctuator circuit diagram.png

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power starving considerably shorter test.mp3

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power starving pew dink pew.mp3

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power starving pew dink pew.mp3

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attdestroyers · Joined: Mar 29, 2012 Posts: 47 Location: Malvern, Ohio

Good work Joe. But, I don't have any BC182 transistors. Is it possible to substitute a 2N type? Any idea which one? I won't get to breadboard this till tomorrow, but it looks fun.

JingleJoe · Posted: Sat Jul 21, 2012 4:29 pm Post subject:

You're damn right it's fun! I got totally carried away with that first demo, that's why it's almost 20 mins long Laughing

Thanks again to Uncle K Wink

Any transistor should do really, just check the power and current rating and do some calculations with ohms law to determine current through R1. Make sure everything is within specification, you know? Smile

off the top of my head 2N3904 should work as well as BC547 and BC337. BC182 is just a common tranny which I have lots of, different transistors might give different results due to differences in gain. Subsequently one may need different resistor values for RB and R1.

diablojoy · Posted: Sun Jul 22, 2012 2:07 pm Post subject:

JingleJoe · Posted: Sun Jul 22, 2012 2:49 pm Post subject:

That could make a nice additional feature to a WSG; supply the oscillators through the above transistor circuit Smile

I took this device to my grandparent's house today (to do gardening, mostly Wink

) my grandad had good fun playing with it too! He made a really nice little beat, a rhythmic sound by adjusting the LFOs very precisely, he somehow got it to sound like hi hat cymbals and snare drums too Laughing

diablojoy · Posted: Sun Jul 22, 2012 9:26 pm Post subject:

you could also take a look at ray wilson mod circuit for the WSG and try power starving through that though i have not looked at the current limitations of that one . would be similar i guess
Interesting to run a CV from a sequencer into such a circuit
with the vactrol i used the vactrol drive section of scott stites mutant filter
not 1v/oct of course but it did sequence the WSG frequencies in a weird and wonderful way.
your circuit would provide basically the same effect if instead of the LFO's you just had CV in jacks ?

JingleJoe · Posted: Mon Jul 23, 2012 1:50 am Post subject:

Yes

however the impedance is a bit low, I suppose one could just power the circuit directly from the LFOs if you buffer them, but I wanted a level control although the transistor is effectively my buffer here.
If I were to add external inputs to this I would mix them with 100k resistors and buffer them with an op amp voltage follower.

Uncle Krunkus · Posted: Mon Jul 23, 2012 2:29 pm Post subject:

Thanks for the appreciation Joe, but I really didn't do much. Just starved a couple of 40106 oscs of the pulses coming out of a 4017 through a transistor. I'm sure that's been done before. And it sounds like you've found a better way of doing that already. Cool

Still, if I've inspired a new path of enquiry for you, then that's great. Very Happy

I must admit that I've had some impedance issues as well. Just changing the output from a piezo to a ruby amp to the input of a mixer, created all kinds of changes in the sounds it produces. (not always in a good way either)

Meanwhile, I've had a whole load of personal problems lately, which have pretty much put a hold on doing anything in the lab for a while. So I look forward to following your progress vicariously, and hopefully bleeding back some of the knowledge I've inspired. Laughing

Keep up the good work! Smile

JingleJoe · Posted: Mon Jul 23, 2012 10:56 pm Post subject:

You gave me the inspiration Wink

This project is pretty much done and dusted, to solve the impedance issue I'd add an op amp buffer to the output which is powered from the main power rail, not the transistor. A 100k pull down resistor might be useful for it's input to stop it floating when the starved portion of the circuit is un-powered.
However I used up all the op amps in an LM324 for re-combobulating those LFOs so I was reluctant to add another op amp for buffering.

I've got some more stuff in the works, keep an eye out for it Cool

Uncle Krunkus · Posted: Tue Jul 24, 2012 2:58 am Post subject:

Maybe a really large pulldown, say 1-10M may let it float around just long enough to be extra interesting!? Very Happy

JingleJoe · Posted: Tue Jul 24, 2012 3:09 am Post subject:

hahaha

I was trying to avoid the glitches associated with floating inputs but you have brought out the lunetta spirit; the glitch gremlin!

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Posted Image, might have been reduced in size. Click Image to view fullscreen.

If you wanted to get floaty weird voltages maybe some kind of capacitor power reseviour, a little filter or something on the buffer, between it and the transistor collector, although that may just smooth things out, maybe an LR filter would do interesting things?
I don't know I'm too sleep deprived to think anymore today Laughing

JingleJoe · Posted: Mon Aug 06, 2012 6:43 am Post subject:

Find below a photo I took of the finished device and a link to some more, I put it up for sale too Smile

More photos can be found here

For sale here!

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