As I understand matters, first spark make air conductive (could say, it becomes plasma), and than for some time you need much less power to light plasma. Very

As I understand matters, first spark make air conductive (could say, it becomes plasma), and than for some time you need much less power to light plasma. Very similar physics behave in classic neon lamps - they use short high voltage impulse to ignite plasma, then much less voltage to support it. So one could make two circuits - one (already existed), will provide enough power to "cold start", other will just provide modulated from waveform voltage (probably, something like pwm). Sure, second circuit should be fast enough to be in time with sound, but again, as I said, need much less voltage. I cannot provide exact numbers now, but as I hear, for spark plug like gap at atmosphere pressure, need few kilovolts to spark plasma, and may be within 1Kv to support plasma. In ICE pressure is much higher, because of this, in electronic ignition usually used up to 100Kv to make spark. If you could make low pressure environment, ~ 1/100 of atmosphere at sea level, you could probably limit to few hundreds volts for all.