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AA-81 Mono Power Amplifier

AA-81 Mono Power Amplifier


  • Use with any preamplifier
  • Ideal power for most speakers
  • Guaranteed long-life—full power ratings
  • Patented ULTRA-LINEAR® circuit
  • Modern styling concept

Hi-fi Rated 35 watts MONO POWER AMPLIFIER has new styling, power to spare and extra value

The Heathkit AA-81 Monophonic Power Amplifier delivers a full hi-fi rated 35 watts. And the new, elegant styling of this versatile and dependable performer will complement any system. A black enameled chassis and a metallic bronze ventilated, expanded metal dust-cover give the AA-81 the modern look that blends with any other Heathkit high fidelity components to make uniform, eye-appealing additions to any room setting.

AA-81 Internal View

Heath's patented ULTRA-LINEAR® circuit and efficient layout make the AA-81 easy to build and provide dependable trouble-free operation.

The price tag alone on this remarkable unit is enough to make it stand out from competitive amplifiers, but when you compare its features, the Heathkit AA-81 is unpatched for value. Heath's patented ULTRA-LINEAR circuit delivers maximum performance. Bias voltage and balance controls assure low distortion—even with unmatched output tubes. A built-in level control and AC switch provide extra convenience. The specially-designed output transformer delivers full rated power with plenty of margin. The easy assembly of the AA-81 is the result of excellent circuit layout and Heath's famous "check-by-step" instructions which assure successful home construction with factory-built performance.

SPECIFICATIONS—Power output: 35 watts Heath Hi-Fi Rating; 42 watts IHFM Music Power Output (0.7% THD, 1 kc) Power response: ± 1 db, 20 cps to 20 kc at 35 watts. Harmonic distortion: Less than 2%, 20-20,000 cps at 35 watts output. Intermodulation distortion: 2% or less at 35 watts output, 60 and 6,000 cps signals, 4:1. Hum and noise: 80 db below 35 watts. Input sensitivity: 0.9 v for 35 watts output. Outputs: 4, 8, 16 and 32 ohms. Damping factor: 16:1 at 8 and 16 ohm taps; 12.5:1 at 4 ohm tap. Controls: Bias voltage, Bias balance, Level, On-Off. Tube complement: 1-6AN8, 2-EL84, 1-GZ34, 1 selenium bias rectifier. Power requirements: 117 v. 50-60 cycles, 100-130 watts. Power outlets: 2 AC receptacles, 1 switched 1 unswitched; Octal socket for pre-amp power, supplies 300 v at 10 ma DC and 6.3 VAC at 1.0 amperes. Color and finish: Black enamel chassis, metallic bronze expanded metal cover. Dimensions: 12" W x 6 3/8" H x 8" D. Shipping Weight: 24 lbs.

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