Air Tight ATM-211 Mono Amplifier features:
- Unprecedented high power 22W derived from broadcast-oriented 211 valve with direct-coupled cathode-follower stage
- All-stage triode-driven non-NF Class-A operation to achieve pure, unimpaired sound
- Independently coiled transformer for amp-stage, bias, heater and relay circuits to remove mutual interferences
- DC-driven heater filament to eliminate hum of output valve
- Relay-activated muting circuit for long life of electrolytic capacitor
- Bias meter to check operation status of output valve