"Wind Machine" - you know you want it!

[Earthscum]

Easy. How easy is up to you. You could use a simple resistor mixer (which would drop some signal), or simple buffer, 10k out of that joined with a 10k off the Volume (output) of the wind machine, into another buffer. You could use a dual OP Amp, or just a pair of JFet buffers. I'll see if I can find a better example than that explanation, search for "simple audio mixer" and should find quite a few somethings in Google images.

eta: Aha! Found the page I was looking for: http://sound.westhost.com/articles/audio-mixing.htm

I love Elliot Sound... IMHO, every bit as good as Play Hookey! ESP tends to stay away from the "mystical" side of audio, and focuses on fundamental through working higher-ended design in very few steps. Great at explaining the math in a simpler form, too.

[timd]

Thanks! I was planning on circuit bending an input on there, but now I have options.

[Earthscum]

So, the only transistors that worked for me were 2N5088 and 2SC1815. The C1815 sounded great, more like pink noise, while the 5088 was definitely in the white noise territory. Also, blown LED's work, too... lol.

I think I found the "Vom-Tune", lol. I had it running through a distortion into my phaser into Nurse Quacky. The attack on NQ softens the peak sweep of the phaser, and follows a bit behind, adding some extra phase depth to the sound. I unplugged it to show off to the woman and started twiddling knobs and she started turning green! I was getting the same sound you get when your ears start to plug up right before you vomit. 

[Cliff Schecht]

Something worth trying in any BJT-based noise generator circuit is to simply replace said BJT with a Zener diode. You put the Zener in the circuit with the anode grounded and cathode receiving the biasing voltage. Zener diodes are designed to operate continuously in reverse breakdown and also happen to make a LOT of noise when biased at the right point. The cool thing is the Zener trick produces VERY broadband (white) noise, we're talking DC to daylight here. Yet another bonus is you don't have to sort through them, every Zener diode I've placed in a noise generator circuit made just as much noise as the one before and after it (or at least good enough for rock and roll, and definitely much more consistent than BJT's!). Something like a 6.8V Zener should work very well with our standard 9V circuits.

[earthtonesaudio]

Would something like this work, or would the 1M be too large to generate sufficient current through the zener?

link to javascript sim

[Cliff Schecht]

Not quite, this is how I do it:


Of course replace the "RF amplifier" with an op amp with some gain (maybe 100 V/V or so). Something to keep in mind is that the gain-bandwidth product of your typical TL0xx op amp is only 3 MHz(ish), so a gain of even 200 will already bring your effective bandwidth down to 15 kHz which may or may not be noticeable depending on who is listening.

Also IIRC the trimpot I used was like 25k and somewhere near the middle of that range was the optimal noise biasing point. It's a simple circuit that at least saves you the hassle of sorting through BJT's, I highly recommend you guys give it a shot before wasting too much time sorting for the worst BJT's in the batch!

[Ben N]

What kind of a name is "wind machine?"  C'mon, Rick.  That just blows.

Definitely not what came to mind when I read the thread title. Different wind, I s'pose. And yes, I can type out a sound demo, but it would be rude.

[mafew129]

I love this circuit so I decided to make a vero layout. Verified.

[GiulioGratz]

Hi guys, i'm thinking on make this noise gen, but i'd like to generate pink instead of white noise! Any idea? Thanks!

[R.G.]

Google "pinking filter".

[GiulioGratz]

Well, i have to apply a -3 db octave filter. I had found something previously, that was something like "a lot" of caps + resistors in parallel... but, where does i have to put them? Could something like this work properly?



Last question: that u41b???

[R.G.]

Here's a simpler one:

http://sound.westhost.com/project11.htm

[GiulioGratz]

Thank you very much!

[merlinb]

Another pinkening filter- very accurate between 20Hz-20kHz:

[GiulioGratz]

Great! Thank you merlinb, too

[Ludwigvan]

Hey guys!
I tried testing the vero layout by mafew129 and i experience some problems with it.
The signal I get is too quiet even at full volume. I'm using the indicated IC and Q but i'm wondering if the problem is with the R1 and R7.
See I can't really confirm the numbers 1 and 7 in the picture of the layout.. I tried swapping between them but the result is the same.
Any ideas would be really appreciated! 

[Mystica]

I love this circuit so I decided to make a vero layout. Verified.

I verify this schematic for vero as well. Works perfect!

But the schematic is a bit vague though, especially the R1 and R7 values...

[Digital Larry]

If using both leads of a capacitor results in a 6 dB/octave filter, wouldn't connecting just one lead give you the desired 3 dB/octave?

Take it easy on me guys, after all I'm "Digital".

[GiulioGratz]

Hi! I made a wind machine some years ago and it works great.
Now a friend asked me a clone, but with a mod: he wants to have input from guitar -> footswitch that selects A = guitar on/noise off B = guitar off/noise on -> output.
I made the circuit on a stripboard (using the layout provided in this thread) but the volume of the noise is really low and there is AC 50 Hz hum.
Maybe i connected my grounds wrong.
How do i have to connect them?
Thank you for the support

[Bipolar Joe]

Hi, all,

I breadboarded the bandpass and vref section, but it doesn't seem to be working too great. Only thing i didn't have was a 47k pot, so I just used a 50k in the hopes it would be close enough. Here's a layout of the breadboard (Sorry for the rats nest, not very good at this).



Can anyone spot a problem? I'm at a loss. Thanks!