PWM Controller - TL494CN
One of the most popular PWM controller ICs use in SSTCs including audio modulating system. These were the first controller ICs used in the early SSTC plasma speakers. They have a modulation input which allows for very easy low-side audio modulation of SSTCs. Our legacy Plasmasonic CW audio modulated Tesla coil uses these as their primary controller.
Click here for the datasheet (PDF)