Knob-twiddler

Mr. Telson was a confirmed knob-twiddler. Often he would work along the whole range of his radio, to 'see what he could get.'

Source: wiktionary

If you're a dedicated knob twiddler what follows can hold no pleasure for you. If jumping doggedly up and down in constant conflict with the electronics of a TV set is your idea of an evening's bliss, then don't read on.

Source: wiktionary

But long live the spirit of the amateur cameraman, the solo recording engineer, and the lonesome knob twiddler.

Source: wiktionary

Recorded in 1995, 'Spaceman' had been hanging around unnoticed for a year when an ad agency knob-twiddler chanced upon it, or rather one very, very small part of it.

Source: wiktionary