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AA-121 Stereo Power Amplifier
Features patented Heath ULTRA-LINEAR® circuit!

AA-121 Stereo Power Amplifier


  • Full high fidelity power rating
  • Mixed-channel center speaker output
  • Fixed bias output stage
  • Front panel controls
  • Beautifully styled

The AA-121 STEREO POWER AMPLIFIER has new-modern styling features

The new Heathkit AA-121 80-watt (40 watts per channel) Stereo Amplifier is the proud successor to the AA-40 all dressed up in a handsome, modern design chassis of black enamel with ivory front panel and metallic bronze ventilated steel dust cover. This powerful "professional quality" stereo amplifier delivers a full 40 watts to each stereo channel, or if you desire, you can channel all 80 watts to a single monophonic outlet. A "stereo-mono" switch ties both amplifiers to one input-level control for monophonic operation. When used for stereo operation, individual level controls are provided for each channel.

Heath's patented ULTRA-LINEAR® circuit provides superb fidelity and the famous "bas-bal" output balancing circuit for reduced low frequency distortion. A phase reversal switch in one channel allows easy phasing of any speaker system. Other features include a mixed channel output for a center channel speaker installation when you want to get rid of the

AA-121 Interior View

The interior of the AA-121 Stereo Amplifier shows the rugged, conservatively rated components that can loaf along at full 80 watts output.

"hole-in-the-middle" effects of stereo applications and fixed bias output stages for minimum distortion. The fused, transformer operated silicon diode power supply provides extremely good regulation and cool operation. The surge protection device and conservative ratings insure long tube and power supply life. Two AC outlets, 117 volts, one switched and the other unswitched are provided for accessory equipment of your hi-fi/stereo system. The power on the AA-121 can be turned "on" or "off" either at the amplifier or the preamplifier, as desired.

This attractive and powerful stereo amplifier is designed for use with any self-powered preamplifier, but its color and lines will blend most tastefully with the Heathkit AA-11 or AA-141.

SPECIFICATIONS—Channels: 2. Power output: 80 watts (40 w. per channel) Heath Hi-Fi Rating; 98 watts (49 w. per channel) IHFM Music Power Output (0.7% THD, 1kc). Power response: ± 0.5 db, 20-20,000 cps at 40 watts output per channel. Harmonic distortion: 1.5% or less, 20-20,000 cps, at 40 watts output per channel. Intermodulation distortion: 0.5% or less at 40 watts output per channel, 60 and 6,000 cps mixed 4:1. Hum and noise: 85 db below 40 watts output. Channel separation: 70 db or better at 1 kc. Input sensitivity: 0.95 volts rms for 40 watts output per channel. Outputs: 4, 8, 16 and 32 ohms per channel; center speaker terminals can be used with 4, 8 or 16 ohm speakers. Damping factor: 16:1, 8 and 16 ohm taps; 12.5:1, 4 ohm tap. Controls: A channel: bias balance, bias voltage, level. B Channel: bias balance, bias voltage, level. Function selector; phase and power switches. Tube complement: 2-6AN8; 4-EL34; 4 silicon diode rectifiers, 1 selenium bias rectifier. Power requirements: 117 volts, 50/60 cycles. 180-220 watts. Power outlets: 2 AC outlets; 1 switched, 1 unswitched. Color and finish: Metallic bronze, expanded metal dust cover; black chassis with ivory lower front panel. Dimensions: 7¼" H x 15" W x 11" D. Shipping Weight: 39 lbs.

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