Monday, 15 May 2017

Light up guitar demonstration

So the light-up guitar is complete and ready to try out.


The chords and scales mode works really well.
And playing blues licks (with the blues scale selected) is great fun. As many guitarists already know, when playing a 12-bar pattern, it's quite common to play a major pentatonic melody over the one (I) chord, and a minor pentatonic melody over the four (IV) and five (V) chords. This is what gives the blues its distinctive "blues-y" sound (for you music theorists, it's the clash of a minor third over a major triad with an added flat 7th that really makes the blues sound like the blues, but the principle is the same).


By just noodling around playing notes from a scale you can get a nice blues-y guitar sound; coupled with a bit of rhythm, there's a very real danger of it actually sounding melodic!


Flicking the major/minor switch makes playing/finding chord tones really easy. Root notes are always in red. Thirds are in pale blue. When in "major" mode, the fourth degree of the scale is bright purple. So find a purple note, and the major third is immediately behind it. Slide into (or hammer on to) that note and you instantly get that blues sound.

My own personal arsenal of blues licks is limited to about three licks. But even then, playing those couple of licks with the fretboard lit up makes understanding how and why they work much easier. You can actually see when you're bouncing around the major/minor third, you can see as well as hear the effect of sliding or bending to a flat seventh, you can see why a particular lick sounds good over the four chord (because it has a fourth of the scale in it) and doesn't always fit well over the five chord.

From a learning point of view, it's a real success.
From a guitar point of view.... well, not so much.

For a start, I didn't do a very good job of clamping the fingerboard absolutely flat when gluing it to the neck. In fact, there's a tiny bit of a back-bow in the neck once it's on the guitar.
Which means I've had to really jack up the bridge and put on some super-heavy gauge strings, to try to get the neck to bow "forwards" a little bit.


with the straight edge sitting on the neck, you can see a slight gap between the ruler edge and the frets on the left, furthest away from the body. Unfortunately, this means the neck has a slight back-bow at around the fifth fret, causing lower notes to "fret out" and buzz really badly.

So although the backbow can (just about) be compensated for, it's at the cost of really heavy strings (13s on the highest E). Which, as you can imagine, makes playing blues-y licks, with lots of vibrato and string bending really tricky.

There's also a dodgy earth problem that needs finding and addressing.
It's barely noticeable when using a clean-tone amp. But add in a bit of crunch (I use the overdrive switch on my amp but the same effect happens with any high-gain effect pedal with any  kind of treble boost) and suddenly you can hear the additional electronics in the guitar signal.


When using the menu, there are audible clicks in the audio signal. But the best is when the LEDs light up. The PWM signal driving the LEDs sounds like someone blowing into an open-ended piece of drainpipe. Very peculiar!

So there we have it - a working light-up guitar. Of sorts.
It lights up. It makes finding and playing scales easy.
But it's an absolute pain to actually play.

Keith will just have to hang on a little bit longer - I'm already started on a new guitar neck which I'll make sure is created flat and not bowed. And maybe we'll try moving the electronics out of the guitar body and hooking up to a separate, dedicated box of tricks, well away from the pickups and anything else that might affect the audio signal....