Thursday 31 May 2012

Working fuzz face pedal

Here's a video showing the fuzz face effect "pedal" working with a Peavy Raptor guitar and miniature Marshall amp.

There's a definite difference between "clean" and "distorted" sounds and we're keen to say that the whole thing works well. The only thing is, after trying out our board, Jason from BuildBrighton turned up and asked us to try out his design - and his works even better!

So we've ended up with two types of effects pedal. Our latest design is more of an "overdrive" distortion effect, whereas Jason's is very much more "fuzzy" - more reminiscent of the original FuzzFace.

(check out the video jump at about 0:44 where the video was paused while we swapped out "our" pedal for Jason's)

Tuesday 29 May 2012

Guitar effects pedals

In preparation for the Mini Maker Faire in Brighton in September, we're busy designing and prototyping tiny guitar effects pedals which can be embedded behind a scratchplate.

As this involves hacking an actual instrument, it seems only sensible to keep track of where we've started from (if only so we go back to it, in the event of something going really wrong!)

The ideal starting point is not necessarily the wiring we start with - even really expensive guitars (for us, anything over about fifty quid is a really expensive guitar) can sometimes have quite shoddy wiring. So we're going to start with shielded wiring, to keep any hum and noise introduced by our effects "pedals" to a minimum.

Here's a typical three-pickup setup with shielding - note that the ground plane should be extended to the underside of the scratchplate, the tone and volume pot bodies and, if possible, the entire inside of the electrics cavity:

Shielded Wiring for Stratocaster guitar

Thursday 24 May 2012

Basic Wah Pedal

As part of a series of up-and-coming BuildBrighton workshops, and in preparation for this year's Mini Maker Faire we're busy putting together some simple effects "pedals" that can be put together inside a guitar, to provide onboard electronics.

We've already started work on a number of fuzz-face (distortion pedal) variants.
This time it's the original Cry-Baby Wah effect that we're looking to emulate. In fact, this circuit design is quite a bit simpler than the Dunlop version, but is perfect for what we're trying to acheive - a simple, workable circuit to act as an introduction to gutiar electronics. Here's the circuit schematic:

And the PCB layout:
Wah Pedal PCB
(as ever, print onto A4 at 100% no scaling for a press-n-peel/toner-transfer-ready image for etching your own)

This is how the final PCB should be assembled:

The beauty of this simple design is that it uses a single 500K linear potentiometer to achieve the wah-wah sound. Which means we can do a lot with this design when it comes to "hacking" up our guitars later. For example, it could be replaced with a digital pot and hooked up to a microcontroller (such as a PIC or Arduino) for all kinds of funky fun!

Tuesday 8 May 2012


One thing we've been keen on over the last 12 months or more, is making our own USB devices. These can be anything - we've made miniature instruments and servo controllers amongst other things, but the idea that you can create a device, plug it into a PC and it just works has been really exciting.

Out in the real world - not Nerdland - the rest of the world is busy getting on with mobile phones and tablets and cool things like that. And leaving us PC lovers behind as we look so archaic, sitting hunched over a notebook/laptop in the local coffee shop. The cool kids are too busy swooshing and swishing on their touch screens to worry too much about a few motors chained to piece of rapidly-becoming-obsolete piece of technology!

So we've had a bit of a change of heart here at Nerd Towers recently.
Rather than trying to continue denying mobiles and mobile computing, we're slowly learning to love it. By which, of course we mean, slowly learning to love Android (installing iTunes on a PC is akin to pouring cold tea down the back of the air vents, shudder, Apple, shudder). But developing for Android means getting messy with Java.

Unless you're already quite proficient with Actionscript (AS3) - then haXe is probably a great place to start. But haXe libraries are pretty limiting. We've not found anything that, for example, allows you to communicate with the USB port. So once again we set off looking for a development suite that would compile for Android, and give us access to the USB stack.

Step forward Basic4Android.

Not only is this a brilliant IDE, offering VB-style syntax and a familiar looking environment (you even hit F5 to compile and run your code for goodness sake!) it also compiles to native Android code - so no pesky AIR runtimes and making your apps incompatible with a large share of the market (AIR only runs on devices with ARM7 or better processors - most mid-range phones are still shipping with ARM6 in them).

And the best thing? USB support!
So far, we've only got a simple "hello world" app working, but it's a start.
But already Basic4Android is looking to be quite a powerful bit of kit that could really kit-start some interesting ideas (a bit like Oshonsoft Basic did for our PIC microcontrollers). It's so great, in fact, that the author is offering a special deal for all of us:

If you like the Basic4Android software, you can buy it from

Put in the voucher code - coxvau - and you'll get a massive 50% off!

And we'll get a year's worth of free support and upgrades. So everyone benefits! But no-one more than you - when you've compiled and released your first app, who knows where it could lead.......