Music From Outer Space Weird Sound Generator

Circuitbenders · February 11, 2008, 10:39:44 PM

Just finished my Weird Sound Generator from Music From Outer Space
http://www.musicfromouterspace.com/analogsynth/YOUR_FIRST_SYNTH/WSG_Reborn/WEIRDSOUNDGENERATORREBORN.html

You can buy the PCB from the site for $15 and its well worth the effort.

Heres a demo mp3 of mine with a bit of delay and reverb added. I haven't really mastered it yet so be carefull at the end as its a bit of a tweeter eater

http://www.circuitbenders.co.uk/demos/WSGdemo1.mp3

catweazle · February 11, 2008, 11:04:25 PM

yeah, Kluster is back!!!! www.youtube.com/watch?v=3lkHvcsZ_nM

very cool stuff, I must have this thing, too. I've ordered it just in the moment

Nice little box you have build!

nochtanseenspecht · February 11, 2008, 11:32:01 PM

wow that looks nice !
sound very simmilar to my realistic reverb (after bending)
pure happyness

computer at sea · February 12, 2008, 06:28:45 PM

Yeah, using a printed board saves a bunch of time. I ended up using his artwork to etch my own, which turned out pretty decent. Here's a picture of the finsihed product posing with an Atari Punk Console:

computer at sea · February 12, 2008, 06:31:27 PM

Also, I meant to ask, how do those knobs attatch? Do they have a screw, or are they the ones for the special knurled pots? The red box looks slick as all get-out.

Circuitbenders · February 12, 2008, 06:43:46 PM

Did you use an HCF40106 or a CD40106? As far as i can tell they are more or less exactly the same chip but i have heard claims that the CD40106 gives more 'pure' sounding waveforms. Although this could be the same as guitarists suposedly being able to tell the difference in tone between completley identical valves.

Those knobs have grub screws (if thats the right phrase) that you tighten with a jewellers screwdriver. The box is in fact translucent dark red plastic so it looks like i'm going to have to find out how to wire in some LFO speed LED's and stick them inside.

It never occured to me that you could mount a circuit in a hollowed out book, nice job

computer at sea · February 12, 2008, 06:55:07 PM

Thanks. I build a lot of stuff in books these days.

For the WSG I used the CD40106. There's an electronic supply store in my town that has bins and bins of discontinued ICs, so I was able to nab a few for about a dollar each.
Not that I've heard the other version to compare it to, but I'd be willing to bet that a human's ear couldn't tell the difference between the two chips.

djsynchro · February 13, 2008, 11:46:26 AM

Hey I just finally got all the parts for mine yesterday, and just now I found the case - happy happy joy!

About the IC: It's the heart of the oscillator, if they switch at different speeds (for example) that would change the shape of the waveform (which is a really unique one, there's a picture on Ray's site) which may or may not be noticeable...

On the soundlab electromusic.com forum they were saying that different transistors in the VCO sound different and to try different types to find your favourite. Talking of which: Did you guys use the 2N3904 or a replacement?

Building is the new bending!

catweazle · February 13, 2008, 12:20:05 PM

CD/HEF 40106 = 45106 = 4106 = 4584

The 4584 produce less noise because of faster hysteresis.

For the 2N3904 all small signal npn transistor can be used (BC548....)

computer at sea · February 13, 2008, 01:33:39 PM

I used a 2N3904, as I had a handful in my parts cabinet.

computer at sea · February 13, 2008, 01:36:14 PM

Also, question for Paul:

Do both of the voices on yours have the same volume, or is one clearly quieter as is the case with mine. I think I may have grounded the controls incorrectly.

Signal:Noise · February 13, 2008, 01:53:06 PM

I really need to pull my finger out and build something cool. everything in this thread looks bloody brilliant.

Circuitbenders · February 13, 2008, 02:00:34 PM

I used 2N3904's and an HEF40106 but i've just ordered a couple of CD40106's to see if it makes any difference. I did notice that mine sounds a lot more 'fizzy' than some of the demo's on the site and the electro-music forum but that could be down to the filter settings.

Quote from: computer at sea on February 13, 2008, 01:36:14 PM
Do both of the voices on yours have the same volume, or is one clearly quieter as is the case with mine. I think I may have grounded the controls incorrectly.

The second voice is definately quieter on mine as well. I'm not entirely sure why that is as the schematics look exactly the same but the tuning is slightly different and how each voice reacts to the 'wacky freq' knob is slightly different as well.

catweazle · February 13, 2008, 02:30:41 PM

I'm waiting for the pcb hadn't build it yet. So the following is theory.
The volume difference between Voice A and Voice B results from component tolerances (resistors)
Those 1M resistors R21/R22 do the volume mixing (decrease for louder output of voice b).
A 1M resistor with 10% tolerance can have a resistance between 0.9 .. 1.1 M for example (+/- 100 kOhm !)
It is better to use "Metal film" resistors not those cheap "Carbon film" ones.

I'm very interested in the differences (if any) in sound between CMOS logic types CD/HEF 40106, 4584 ...
Even TTL logic 74xx14 can be used (but they need 5V power supply!)

djsynchro · February 14, 2008, 11:18:33 PM

I have a HEF40106 that I was planning to use but there's a C40106 I ordered in the mail so I'll try both I guess.

I attempted to build the WSG on vero board last year and only ever got it to half work, I replaced a transistor with a different type and it sounded very different after that! Abandoned it but now there's a PCB! That should help...

If I find any major differences I'll post it..