CIRCUITBENDING TIPS

WARNING

The most basic idea behind circuitbending is the art of the creative short-circuit. Basically this amounts to taking a piece of wire and soldering it across two points on a circuit board in order to send digital data into places on the circuit where is was never meant to be. Very occasionally this will result in a puff of smoke and a sad fizzing noise but with experience you can persuade an otherwise dull machine to disgorge sounds more savagely ferocious than you could have possibly imagined. Obviously we can't go into specific details for every machine on this page but here are some basics to get you started.

For a first bending attempt you really can't go far wrong with a speak&spell, theres loads of information out there, you can't fail to get some good results and they are difficult to kill, unless you mess with the power supply board, so don't. Theres nothing for you there.

What you're going to need to get started:

We're not actually sponsored by Rapid or JPR Electronics in any respect, it was just easier to find links to general examples on those sites. You can probably find equivalent items at any decent sized supplier in your country. Some of these links will be out of date, but we'll do our best to update things every now and then.

Soldering Iron -
Don't just buy the cheapest thing you can find from Maplins or Radio Shack. It'll be a false economy and you'll just end up getting frustrated and end up buying something better anyway. We've been using a couple of THESE for years and they work fine. The yellow irons made by Antex are also perfectly usable

Solder -
Lead free solder is crap. Honestly, its almost unusable. Yes, its not going to poison you but then neither is solder that contains lead unless you eat the stuff. Lead free solder needs a much higher temperature iron which is inevitably going to melt plastic bodied components, and you'll end up with no end of dry joints. Theres a reason why medical and military electronics is exempt from rules on lead content in solder. Just get some standard 60/40 tin/lead solder similar to THIS or THIS. Smaller amounts will be available from local stores, or sites like ebay

Resistors -
You don't need anything expensive or over specified here. Go for 1/4 watt carbon film resistors and buy in packs of 100. That may seem like a lot but you'll use them sooner or later, and its the same price to buy 100 from a decent supplier as it is to buy 10 from a high street shop. These resistors from Rapid are fine and cost just over 70 pence for 100. Carbon film resistors have an accuracy of 5% either way of the stated value. This is fairly insignificant in electronics terms, but if you need something more accurate in the future you can get metal film resistors which are twice the price, but have a 1% accuracy. You will inevitably build up a collection over time but good starting values would be 22R, 100R, 220R, 470R, 1K, 2K2, 4K7, 10K, 47K, 100K, 220K, 470K, 1M and 10M. If you live in the US the 470R, 4K7, 47K and 470K values will probably be 500R, 5K, 50K and 500K, although we've never been entirely sure why this is.

Potentiometers -
around 1K, 47K, 100K, 470K and 1M to get started. Again, the 47K or 470K values will often be 50K or 500K worldwide, but this probably won't make any difference. Pots are cheap so its a good idea to get a stock of a few different types. Start with linear and get hold of some log response pots if you find that all of the pots effect is up at one end of its rotation, Splined shaft pots made by ALPHA are probably the most popular types, but you can also get pots with solid metal shafts like THESE. Bear in mind that there are many different types such as 9mm vertical or horizontal mounting, 16mm, 24mm, switched etc etc. Standard 16mm splined or solid shaft pots are the most popular.
The type of shaft your pots have will determine what kind of knobs you can use.

Output Jacks -
Just about any audio socket you can find would be usable, but 2 pole (mono) 1/4" /6.35mm or 1/8"/3.5mm jack sockets are the most popular. You might as well get switched ones with 'break contacts' as they are usually about the same price as non-switched ones. You may not know what that means yet, but think of it as a normal socket with an added bonus.

Wire -
We usually use 10/0.1 equipment wire for general work. The numbers 10/0.1 mean that the wire has 10 strands each measuring 0.1mm in diameter. We also us 7/0.2 wire for anything that needs to have a stronger connection. Anything thicker than that and you're liable to have space issues if you are using a lot or wiring, but it should still do the job.

Switches -
Theres some useful information on Wikipedia about the various types of switch, e.g. SPST, SPDT, 3PDT etc. The main thing to say about switches is that it doesn't pay to buy cheap rubbish. Never buy switches with plastic threads for the fixing nut like THESE as they are useless. The thread will strip from the shaft when you tighten the nut and the soft plastic will melt when you solder the contacts. If you want to buy sub-miniature toggle switches then THESE are a much better bet. Just about any panel mount standard size (sometimes called miniature) toggle switch from a reputable supplier will be alright. Switches like THESE are fine and you can often get bargain packs of 50 or 100 switches from Hong Kong based sellers on ebay. The quality of switches from China can vary wildly so be careful. Never get the light blue versions of those switches as they are useless. The dark blue ones as shown on that ebay listing are much better.
The most useful switch types are SPST, but SPDT, DPDT and SPDT 'centre off' are also useful. For guitar pedals you will most likely want 3PDT foot switches

Push to break buttons -
These come as various shapes and sizes but the most commonly used ones seem to be THESE or something like THESE. Don't buy the really cheap ones like THESE. When they say 'These switches are not suitable for industrial applications' what they mean is 'These switches are not suitable for ANY applications'.

Push to make buttons -
The same as above but they make the connection when you press the button rather than breaking it. There are hundreds of different designs of push to make switches.

Screwdrivers & bits -
Jewelers screwdrivers are always useful, as are a set of philips head screwdrivers and some torx / hex bits.

Drill -
To drill holes for switches and controls. Dremel type multipurpose hobby drills are a lifesaver.

Knobs -
There are thousands of different types of knobs available. The main things you need to look out for are the type of pot shaft they are designed for. The most common types are splined/serrated and D-shaft, which are both push on knobs, and 6mm/6.35mm shaft, which tighten to the pot shaft with a grub screw.

 

What you may need in the future:

Multimeter -
to test for continuity and for voltages. This doesn't need to be anything really expensive as THIS will do the job for under £10. You'll probably want something a little better after a while so it might be an idea to just start with something like THIS

Solder Sucker -
Sooner or later you're going to want to remove a component from a circuitboard. Combined with solder wick, the solder sucker / desoldering pump is the one of the most cost effective ways to do it.

Solder mop / wick -
Like a solder sponge that sucks melted solder from joints. Comes under various guises and thicknesses but THIS is a decent version at a good price.

Patchbay Sockets -
Some people go for multiple PHONO SOCKETS, others go for 3.5mm JACKS and others go for single pole 4mm SOCKETS. Which one to chose is often dictated by the space available and the thickness of the panel.

LED's -
There are hundreds of different types of LED's in dozens of different colours. Its often a lot cheaper to buy a bag of 50 or 100 LED's from China than it is to buy 10 or 20 from a normal supplier. Theres loads of information and tools for using LED's HERE including a very handy LED resistor calculator.

Glue -
Useful for all kinds of things. Superglue is useful but it can react strangely with some plastics and may not be very strong in certain situations. We'd also recommend getting hold of a decent two part epoxy resin glue.

Trimmer Pots -
Also known as preset pots, these are small potentiometers that are usually only adjustable using a small jewelers screwdriver. They are useful for adjusting the maximum or minimum value of a larger panel pot, or if you don't have a fixed resistor of quite the right value. Values of 10k, 47K, !00K and 470K are probably the most useful. There are dozens of different types but THESE or THESE are fine.

Tools -
Hacksaws, drills, pliers, wire cutters, tweezers, socket sets and files come in very handy. Whatever you think you need, you will need more. The NIBBLER is an incredibly useful tool for cutting holes in front panels

Oscilloscope -
This is only for the hardcore bender (theres a phrase you don't hear everyday) If you don't know how they work or what its for, then you probably don't actually need one!

NEXT >>>