12AU7 / ECC82 Vacuum Tube – Dual Triode for Phase Inverter & Headphone Amp Stages

The 12AU7 (ECC82) is a medium-mu dual triode used where a preamp stage needs headroom and current capacity rather than raw gain.

• Tube type: Medium-mu dual triode
• Base: B9A / Noval 9-pin
• Heater: 12.6V AC (0.15A) or 6.3V AC (0.3A parallel)
• Typical use: Phase-inverter and line-driver stages in guitar amps; headphone amp output stages

ECC82 equivalent.