12AU7

Miniature 9-pin general-purpose medium-mu twin triode universally used for audio voltage amplification, phase inverters, multivibrators, and low-frequency oscillator circuits. Equivalents: ECC82, 12AU7A, 5814A, 6189, CV4003. Real-Life Examples: McIntosh MC30 power amplifiers, Vox AC30 guitar amplifiers, Ampeg SVT bass amplifiers, organ preamplifiers.