The term 'AMP KNOB' is a combination of two words, 'AMP' and 'KNOB'. An AMP is an abbreviation for 'AMPLIFIER', which is an electronic device used to increase the power of a signal. A KNOB is a circular control used to adjust the settings on a device. The crossword solution for this term is 'TREBLE', which is a type of audio frequency range that is higher than the normal range. TREBLE is often used to increase the clarity and presence of sound in audio recordings.