28.05.2015 Updated: 28.05.2015 #7

Making of DIY synth Weird Sound Generator

Эта статься на русском ›››

So one day I realized I needed some new project to work on. And I remembered that one of the teachers at SAE Institute where I recently studied mentioned something about "lunch box synth" being a cool thing to do.

I googled it and discovered a Music From Outer Space website — Your Synth-DIY Headquaters.

I looked at all the cool projects that were there and decided to make one too, despite I had very little knowledge about building electronics.

I probably did a lot of beginner mistakes and in the end the synth didn't sound as it should have, but still I am very satisfied with it and think it was a lot of fun to build it.

Below you can see how it went for me and listen to some examples.

Your First Synth

When I googled for the DIY-synth I found a page Your First Synth and decided to build it. I didn't want to buy a prepared circuit board but to make it all by myself.

I started by looking for a place to buy electronic components in Stockholm and found this cool store Elfa that seemed to have all the things from the list. I made anorder (~€30) and few days later received a box with a lot of small plastic bags with my components inside.

The next step was to start soldering. After fixing several components on the board I realized that there were some differences between schematics and the layout diagram and with my complete absence of knowledge about electronics it became a stopper.

So I again I started googling trying to find answers to my questions and decided to read the description of this synth more carefully. And only then I noticed the big red letters that read that this was an old and outdated page and I should go to a new one!

Making of DIY synth Weird Sound Generator (MFOS WSG)

Weird Sound Generator

The link to the new page didn't work, so I googled again and found a page for the modified version of that synth that was called Weird Sound Generator. The list of components included most of the components that I already bought, but I had to make a new order to get remaining parts (~€30).

On the picture below you see the beginning of the circuit board assembly. I think many people are laughing right now at my lousy work, but I still think it was pretty good for a first timer!

You can also see that the output wires (with the labels) are really short. Two reasons for that – I didn't think that long ahead about how I will connect the faceplate to the circuit board. And another reason is that I didn't have enough wire. I bought six meters of wire and thought it would be more than enough for me. I couldn't be more wrong – it the end I used around 25 meters of wire!

Making of DIY synth Weird Sound Generator (MFOS WSG)
Making of DIY synth Weird Sound Generator (MFOS WSG)
Making of DIY synth Weird Sound Generator (MFOS WSG)

Here you can see the completed circuit board. The elements are placed so far apart from each other because my soldering iron had a pretty think tip, and besides my soldering skills didn't allow me to do too much of fine work :)

Making of DIY synth Weird Sound Generator (MFOS WSG)

In order to control my work I printed out all possible schematics I could find and checked the connection of each element on the board.

Making of DIY synth Weird Sound Generator (MFOS WSG)

Prototype

When the circuit board was done, it was time to create a faceplate. I wanted to make a wooden box with the faceplate of brushed aluminum. But I started just with a cardboard prototype.

I made my own design of the faceplate, printed it out and cut it out of the cardboard. Then I attached all the switches and potentiometers.

I decided to add a volume knob and the light diode for the power switch.

Another modification that I came up with (by myself :-) was the channel switch, that would send the signal to both left and right channels. When it is in mono position — the synth can be used as ordinary mono instrument, but the stereo position allows you to connect headphones or any other stereo audio system to the synth and make it sound in both channels.

By the way, the light diode that I used is the one of the first light diodes ever produced in Soviet Union. I had several of them in my "treasure" box from when I was 12 years old and was going to a radio building circle for some months. And then by some reason I brought them all the way from Ukraine to Sweden. I now I found good used for it :)

Making of DIY synth Weird Sound Generator (MFOS WSG)
Making of DIY synth Weird Sound Generator (MFOS WSG)

The backside of the cardboard faceplate. It was much easier work than to build a circuit.

Making of DIY synth Weird Sound Generator (MFOS WSG)

Now I put everything together. So in theory this bunch of wires should be able to generate sounds now. It is hard to believe.

Making of DIY synth Weird Sound Generator (MFOS WSG)
Making of DIY synth Weird Sound Generator (MFOS WSG)

Time for the first test! I put my construction over a wooden box that I found in some store.

Making of DIY synth Weird Sound Generator (MFOS WSG)

This is how it looked like. I connected it to the small computer speakers and turned the power on..

Making of DIY synth Weird Sound Generator (MFOS WSG)
Making of DIY synth Weird Sound Generator (MFOS WSG)
Making of DIY synth Weird Sound Generator (MFOS WSG)

First run

And it worked!!! I couldn't believe it! The sound was similar to the sound I heard on videos from other people, which meant that probably I even managed to do it without obvious mistakes! I'm goood! :)

I spend next couple of weeks playing with it.

The real thing

Now it was time to make a real nice box. While playing with the prototype I noticed that the power and channel switches should change places. I also decided to add too more switches to be able to turn on and off voices A and B to be able have more simple and clean sound when needed. Also I fine-tuned other design elements to make it look more consistent.

At the time I went to Kiev for a couple of weeks and thought that probably it would be easier to order a faceplate there.

I found a company that produced different door signs and sent them my design. Unfortunately they couldn't make my plate out of solid aluminum, so I had to agree that they used 0.7 mm aluminum plate that they fixed to a 3 mm plastic board.

After a couple of days I got it delivered to me. It looked great!

Making of DIY synth Weird Sound Generator (MFOS WSG)

I borrowed a drill and made holes in the plate. Since the aluminum plate was so thin, the edges around the holes bent inside a bit during drilling.

Making of DIY synth Weird Sound Generator (MFOS WSG)
Making of DIY synth Weird Sound Generator (MFOS WSG)
Making of DIY synth Weird Sound Generator (MFOS WSG)

Gathering Storm

Now I needed to fix the box. As I mentioned earlier, I bought a wooden box in some store. It was made of some very dry and very light wood, kind of like balsa.

I wanted to cut it so the faceplate would be fixed angularly. I managed to cut a 5 mm wood with a simple paper knife.

Then I added some little constructions of wooden pieces to hold the battery box, circuit board and the faceplate.

But the biggest challenge was to organized the wires. A friend suggested me to use COM-connectors to be able to connect/disconnect the faceplate from the circuit board easily. He also suggested that I fix all the wires to the circuit board with a tie-wrap so they don't fall off so easily.

Making of DIY synth Weird Sound Generator (MFOS WSG)

The problem here was that I had to disassemble my prototype almost completely and then put it back together. Doing this there was a lot of space for error to occure. But I decided to go for it since I didn't have any other choices.

Making of DIY synth Weird Sound Generator (MFOS WSG)
Making of DIY synth Weird Sound Generator (MFOS WSG)

Then I needed to do a similar procedure with the faceplate. I connected longer wires, soldered them to the COM-connectors and fixed to the plate with the pieces of velcro.

Making of DIY synth Weird Sound Generator (MFOS WSG)
Making of DIY synth Weird Sound Generator (MFOS WSG)

Fail

So now I was ready to connect these things together and see if the synth still worked.

I had a bad feeling in my stomach. I connected the synth to the speakers and turned it on..

There was no end to my disappointment! The synth was still able to sound but the sound was completely different!! It got a lot of noise and distortion. The voice A and voice B seemed to work a bit differently now. The oscillator 1 seemed to have lost some connection to oscillator 2 and generated a plain sound. The resonance knob didn't have any effect on the sound what so ever. My two new switches didn't work the way I wanted — they didn't turn off the voices A/B but only made them sound quiter.

I got upset but summoned some strength for debugging session. I spent 5 hours checking every cable, every connection, every change that I made. But everything seemed to be as it should have. I didn't mix the wires or anything. I couldn't see what I did worng.

I got really depressed. For almost two months I couldn't think of anything else but this project and now I got such a failure.

I didn't know if I had to build everything from scratch or keep looking for mistakes. But I felt that I didn't have any more energy left.

After some days a friend took my synth and started playing with it at the kitchen. And then I realized that somehow the synth still worked.

Final result

It wasn't the same sound as in the cardboard prototype but still it was possible to squeeze out some interesting sounds out of it.

And after some thought I decided to leave it as it was. Maybe later I'll make another one that would function properly.

So now I want to present to you my Weird Sound Generator that generates ever weirder sounds that it should have :)

I hope you like it.

Making of DIY synth Weird Sound Generator (MFOS WSG)
Making of DIY synth Weird Sound Generator (MFOS WSG)
Making of DIY synth Weird Sound Generator (MFOS WSG)
Making of DIY synth Weird Sound Generator (MFOS WSG)
Making of DIY synth Weird Sound Generator (MFOS WSG)

Don't laugh too hard at the video below, it was my first Youtube video ever :)

Cost

I also decided to publish all the expenditures I had while building the synth. This doesn't include the cost of additional tools I had to buy.

WSG Expenditure chart

ComponentAmountPrice
Faceplate1€13
Box1€14
Knobs12€19
Wires~30 m€23
Switches10€26
Potentiometers12€41
Electronic Componentsmany€41
Total:€177

Downloads

Download my WSG Faceplate design (PDF, 452 kB)

Summary

This project showed me that building your own sound toys is extremely fun. I do recommend it to everybody.

I'm sure I'll build some other synth later, let me just finally finish my university.

If you have any questions or comments – you are welcome to contact me.

Good luck.

You read all the way down to the end of the page.

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