Older Synths: My Second Synth

Older Synths: My Second Synth

Hackaday: How to Make a Digital Synthesizer

http://hackaday.com/2008/05/01/how-to-make-a-digital-synthesizer/

2012. This article taught me so much, mainly because you're building in small sections and it's very clear what's being added at every new junction.  For this synth I had access to a laser cutter curtesy of the UDK in Berlin, so the front panel was laser-etched onto some black perspex and enclosed in some stained wood.

My First Synth...

Back 2012 I built my first little synth, the classic first DIY synth; an Atari Punk Console.  Sadly it didn't work very well as I'm pretty certain I put in some caps the wrong way around, but it was enough to get me started.  The PCB from Synthrotek here;

http://store.synthrotek.com/Atari_Punk_Console

Figuring Out Resistance to Make a Synth with a Keyboard

This is an older video from when I'd just started learning electronics, but for me it was great figuring out that you could have an array of switches with different resistances to form a DIY synth keyboard;

Repairing the Volume Control on a Crosley HiFi

The volume knob on our Crosley HiFi hadn't worked for ages so I declared in a rage that it would be fixed.  I opened it up and found a similar looking rotary encoder for €1 on ebay.  Search for 'Rotary Encoder'.

Open the front gently with a screwdriver

Remove the screws on the next panel

Being very careful, disconnect the connecting wires at the base (don't pull the wire)

You can walk out the larger connect using a screwdriver at the base and prying it slowly

Now with the pcb removed, take off the front plastic volume and tuning knobs and remove the 6 outer screws on the back pcb (ignoring the others screws on the board).  Here's where you now have to desolder the broken encoder pot...

I had to snip the 3 little legs of mine, then using pliers, solder the tips and slowly pull them out (making sure not to remove the solder pads).  The larger legs, for some reason the solder wouldn't melt until I held the iron on the actual pad for what seemed like ages.  Not sure why that was but I managed to get the thing out eventually. 

Then solder the new encoder into place.  I had to file the main legs down on mine down to get it to fit.

The broken encoder (with the legs snipped);

After putting it all back together again, everything should now be working like new.  Except for some reason my volume is now in reverse, which probably means there are different types of rotary encoders, but as it was my first time working with them I'm pretty happy.

Setting up a 3.2 inch Banggood.com Raspberry Pi 3 / Pi Zero tft screen on Raspbian Jessie

Here's a video of how to set up the banggood 3.2" raspberry pi TFT monitor.  Works with Raspberry Pi 3 and Raspberry Pi Zero under the latest Raspbian Jessie (May 2016) image.

Link to the screen;

http://www.banggood.com/3_2-Inch-TFT-LCD-Display-Module-Touch-Screen-For-Raspberry-Pi-B-B-A-p-1011516.html?p=ZQ230228623252015108

Where have you been?

The last 3 or 4 years I have been studying electronics with the aim of making a synthesiser.  I'll use this blog to document this and to maybe help others along the way 

Make Electronics Experiment 18: Reaction Timer 

For anyone attempting this, I'd advise reading the errata on the website first: don't connect pins 4 & 5 of the 4026's to ground and swap the R10 1k resistors for for 10k.   The 1uF capacitor should be 0.1uF etc.  Also, to get mine to reliably work I had to remove the the positive pin connection on IC1 pin 16.