6AU6A

Miniature 7-pin sharp-cutoff pentode featuring controlled heater warm-up characteristics, widely used for high-gain RF or IF voltage amplification and low-distortion small-signal audio stages in consumer electronics. Equivalents: 6AU6, 6136, EF94, CV2522. Real-Life Examples: McIntosh MR65 tube FM tuners, vintage Collins shortwave communication sets, classic Gibson and Fender guitar amplifier tremolo circuits.