Our last neon tube modulator for cars (SILICON CHIP May 1997) proved quite popular, but what do you do if you don’t have a sub-woofer output from your stereo system to drive it? This latest version solves that problem.

As well, the original unit turned off the neon tube for each bass beat but some readers wanted the neon to fire on the beat. This unit can do both.

Oh! You do have a sub output on your system but you’d like to use this updated circuit? No worries, just omit three capacitors and off you go.

How it works

Fig.1: the complete circuit has just one IC, three transistors, a couple of diodes and a small handful of resistors and capacitors. LED1 is not shown on this circuit: see the wiring diagram.

As you can see from the circuit (Fig.1) and photograph of the PC board there isn’t a lot to it. One IC, three transistors, a couple of diodes and a small handful of resistors and capacitors and its done.