5751

High-gain (mu=70) miniature 9-pin dual triode engineered with an asymmetric internal layout to provide low-noise, high-fidelity voltage amplification in precision audio preamplifiers. Equivalents: 12AX7 (closely related but with lower gain), 12AX7A, ECC83. Real-Life Examples: Vintage McIntosh C22 preamplifiers, high-end vintage acoustic studio recording desks, specialized laboratory audio meters.