- 1. intro
Of course we couldn’t just leave it at that could we? Oh no. You see it’s such a lovely clear piece of acrylic, it just had to be illuminated from the inside. No really, it did…
If you’re gonna put lights inside a guitar, you gotta see what’s already there :)
Here we are opening it up to check the size and shape of the cavity, which is nicely routed, and all the hardware is attached to the frontplate (so no major disassembly required).
Some rummaging on the Maplin website turned up the ideal light source - apparantly designed for lighting around vehicle bodies, these flexible LED strips are low power, super bright, can be cut into smaller units and will bend round inside the cavity.
To provide a bit of colour, I bought two strips, one white and one blue, and a toggle switch to select between them.
After much careful measuring, some cutting and a fair bit of soldering on wires, the light strips can be taped into the cavity like this. Note that I have soldered the strips with the negative sides commoned together, which cuts down on wires and prevents nasty short circuits if the parallel strips touch.
In order to select different colours, we put in a SPDT toggle switch with a centre detent (ie: off). To this we connected the feeds to the lights, and a link wire to the power input, which comes via…
The necessary 12V supply was fed to the guitar via the middle ring of this stereo jack socket, a stereo screened cable and a custom made breakout box on the floor, to which a suitable 12V supply is connected (we’ve been using an old PSU from a force feedback steering wheel).
Although this worked, it wasn’t ideal for a couple of reasons: the pickup signal and lights share the ground connection at the socket, so ground lift due to lighting currents causes clicks in the signal; pulling the plug in/out momentarily short circuits all the contacts on the plug which could damage both the supply and the amp depending on what shorts first. Not good.
We subsequently replaced the Strat-style socket mounting plate with a flat acrylic plate, and added a standard 2.5mm power socket. We also changed to using a switched mode power supply from an old LCD monitor which neatly avoids any mains hum. It’s now quiet when operating and safe from short circuits - still using the stereo socket with the intention of sending digital lighting control signals to the guitar…
Need I say anything? Just how cool is that? :)
Seeing just how darn bright this is, we are now planning on putting a dual dimmer circuit in the guitar, with perhaps an audio sensor chip (National Semi LM4970 or the like) so the lights follow your playing and/or using the middle ring of the stereo socket to deliver a UART signal from a remote lights controller (DMX via a PIC to the I2C bus input of LM4970 maybe?). Your suggestions are welcome!