I'll cut the bricks out after etching the chimney. Then I'll fix red, orange and yellow behind the holes.
As it's a BMP style effect, I first thought that I would try using red LEDs as one of the pair of clipping diodes, which would shine through the holes. Would be an elegant solution.
However, while this can produce a nice sounding distortion (see EQD Hoof), the LEDs don't have enough current through them to light up very brightly.
Onto Plan B.
I stipboarded a very simple circuit that splits and buffers the input, sending the signal to the Muff and also through a side chain that boosts and rectifies the guitar signal (an envelope follower) and then feeds LEDs. This works perfectly! The LEDs don't just turn quickly on and off; they vary in brightness depending on how hard you play. They flicker just like fire!
I found a bonus too. The rectifier circuit requires a couple of diodes. These can be LEDs! So the circuit want just drive the LEDs, it actually contains two within itself, that have the same flickering effect. So I think I'm going to use 4 LEDs in total to produce the fire effect.
I hope it looks as cool as I think it will.
Pics and maybe vid to follow when I've built it
