Thursday, 25 August 2016

Older Synths...

Music From Outer Space: Noise Toaster

2014?  This could probably be considered my first 'real' synth, mainly because it has pretty much all the functions of a synth you'd buy from a shop.
Under that perspex panel is an absolute maze of wires, so I was pretty surprised when it actually worked the first time.  That probably says more about the detailed guides rather than my handy-work. On the MFOS website there is a ton of synth DIY content, including instructions on how to build the noise toaster (plus info on how & why it works), also recommended is Ray Wilson's book which although much of the content is the same as the websites, it's pretty indispensable reading (and the only current synth DIY book around);

Also at this point I'd purchased a few wood working machines, namely a Proxxon table saw and sander;

The table saw cuts up to 8mm MDF (maybe 1cm?), but sadly the guide rails only let you measure a width up to 7cm, unless you go rogue and cut freehand without the guide.  That's something I might hack one day, but as it is it means the max width of wood is often only 7cm, which is generally enough for my synths, but it'd have been nice to have the option to go larger.  It's tiny though, so can be kept ok in my small apartment.  I'm on my second blade after 2+ years of use (and that's only because I cut some metal sheets which blunted it pretty rapidly).

This machine suffers the same faults as the table saw; mainly in that it's too small.  A good workman always blames his tools.  But still, it fits in a cupboard nicely when not in use, so until I get a full size work shop it's something I have to live with.  Both machines are at least of pretty high quality, so if space is an issue for you I guess I'd recommend them.  I use it to sand the edges down on my wood when they don't match up, plus to give a uniform surface finish, and sometimes to round off corners.

Tuesday, 23 August 2016

Casper Electronics Drone Lab Synth

Casper Electronics Drone Lab Synth

Casper Electronics is a fantastic resource for synth-related adventures.  I built their Drone Lab Synth and was pretty happy with the results.  When I get some extra free time I'll have to post some audio examples of it.

Thursday, 18 August 2016

My First Arduino Synth

My First Arduino Synth

Notes and Volts have some great videos over on Youtube detailing the build of a little Arduino Midi Synth.  Originally it lacked MIDI but they've kept adding features with the newer videos and now it's become a pretty useful instrument, as well as a fantastic lesson in Arduino Synthesis;

Part 1

Part 2

Part 3 - Line Level Upgrade

Part 4 - Adding MIDI

This was also my first synth that I connected to the mains power supply and quite amazing I didn't electrocute myself!

The project box / enclosure for this synth came from Conrad for €4.50;

Wednesday, 17 August 2016

Banggood 2500mW Laser Engraver Setup / Fan Repair

Banggood 2500mW Laser Engraver Setup / Fan Repair

After using the Laser Cutter at the UDK in Berlin, then no longer having access to it once my girlfriend had graduated, I'd convinced myself that I needed a laser engraver for engraving all my perspex panels that I'll build in the future.  Now obviously the one at the UDK cost something like €30k and was the size of a car, so I wasn't going to be getting one of those anytime soon, so I set my sights a little lower, like €300, and the size of a normal printer.  For that price you can only really buy kits from China and then build it yourself.  Once you get to the €600 mark, you can get the pre-built Chinese ones that may or may not meet EU safety standards.  Seeing as though building a kit didn't scare me (ok it did but I'm cheap) I took a gamble and ordered a 2500mW 30x40cm laser engraver from


I settled on this machine because the next most powerful laser was nearly double the price, and also the print-bed was the largest I could find on banggood.  30x40cm should cover most of the objects I need engraving, and the bigger ones I can bodge together. 

The machine itself is basically 3 stepper motors connected to a frame that's controlled by a cloned Arduino Nano.  The kit comes with absolutely no instructions or software, although now it looks like banggood may have added some vague details to their site.  At the time all I had to go on was this rather blurry video;

It took about 5 hours to build and by far the worst part was having to listen to that fucking song a thousand stupid times.  Finally built, and with only a few screws and washers leftover (which I told myself were 'extras' and not leftovers. Definitely.),  it was now time to hook it up to the computer and engrave some stuff.  


This is where I hit my first major problem, I have a mac and I struggled to get to get much printed at all.  Banggoods website says that this is for windows PC's only, but I knew that GRBL (the controller software for the arduino) is freely available for the Mac so I was pretty confident I could run it.  After literally a month of trying different setups I finally gave up trying.  I'd managed to use GRBL and Inkscape but the laser wouldn't turn off when it was supposed to.  I've no idea why, and once I'd played around with the g-code and still couldn't get it working I took the lazy way out and threw money at the problem:  I bought a windows PC.  I ended up getting a Lenovo Thinkpad X220 for pennies on eBay.  These were originally made by IBM before they were sold off and are used on the international Space Station due to there reliability.  So it should be good enough for me.

I loaded up 'Benbox' which is what banggood recommend to engrave with and it worked first time. 

FIRST TIME!!!  After a month or two of fiddling with the Mac!


The problem now was that I noticed the fan that cools the laser wasn't working.  Banggood sent out a replacement but that still meant waiting for another month until it arrived.  Using the laser without the fan will drastically reduce its working lifespan, and seeing as though the replacement laser module costs nearly as much as the whole engraver I though it was best to wait.

Putting on the replacement fan was as simple as desoldering the old one and re-soldering the new one.

After that the fan worked perfectly :-)
For now I've been using the Benbox software as it seems to be doing everything I need, so I'll put off moving onto any more advanced software for the future.


One of the Banggood reviewers has some great tips for using the Benbox software over on his site;


The site's in French but Google Translate does a pretty good job deciphering it.  Basically it boils down to keeping the speed and the feed rate the same.

Writing on Card:

Here are my settings I've found pretty good for writing fine lines (not cutting) on card;

Engraving wood

For fine lines on MDF I've found these settings pretty decent;

Engraving Perspex:

Actually since taking this photo, I now engrave perspex at a speed of 300, feedrate of 300, time and step of 1.  I haven't fully figured out the best steps for perspex, but this is where I'm currently at.  I might consider lowering these specs and then simply pressing the engrave button twice if they're not sufficient.

I'd have to say I'm pretty happy with the Engraver now.   Just remember to wear those eye goggles because this machine is very easily capable of blinding before you have time to react (so don't use reflective perspex!).  Here's a quick preview of where I'm at currently with my perspex engraving (I'll write about this build in the future);

Tuesday, 16 August 2016

Older Synths: My Second Synth

Older Synths: My Second Synth

Hackaday: 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;

Wednesday, 3 August 2016

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;

Tuesday, 2 August 2016

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.

Monday, 1 August 2016

Setting up a 3.2 inch 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;