Heathkit AA-151 (1962–1967)

Name: Heathkit AA-151
Brand: Heathkit

Two 14-watt channels, one patented circuit, and a soldering iron you supplied yourself.

Overview

Heathkit's catalog copy for the AA-151 gave 28 hi-fi rated watts, 14 per channel, with a 32-watt IHF music power rating at 0.7% THD into 1 kc. Those numbers won't move a modern speaker. But the AA-151 was a complete stereo integrated amplifier that a hobbyist could assemble at the kitchen table and then match, cabinet for cabinet, with the AJ-11 or AJ-32 tuner sitting above it on the shelf. The styling gave it away: a tan vinyl-clad steel cabinet, charcoal gray front panel, and anodized aluminum trim. It measured 15½" W x 5½" H x 11" D and weighed 27 to 30 pounds, depending on which year's catalog you read.

The AA-151 was a full control center. It had four stereo inputs - magnetic phono, crystal or ceramic phono, tuner, and auxiliary. That covered every source a mid-'60s household was likely to own, from a magnetic-cartridge turntable to a tape recorder to a TV set tapped for audio. A 6-position mode switch handled stereo, stereo reverse, and full monophonic operation of any input, so a mono LP played through both speakers without a Y-cable. The dual-concentric volume control let owners trim each channel separately, then lock the two halves together with a friction clutch so normal listening didn't need constant re-balancing. Bass and treble were ganged to adjust both channels at once.

Heathkit's own advertising billed the AA-151 as offering styling, features, and performance that exceeded competitive units selling for twice the price. The company leaned hard on the build-it-yourself appeal, with testimonials from customers like a Mr. Robert R. Tyrrell of Cloverdale, California, who wrote in to say his family had finished the kit and found the construction and sound both first-rate. That is marketing, not independent measurement, and should be read as such. The underlying pitch was real, though. This was a preamp and a power amplifier in one chassis, with separate preamp and power amp stages per channel, sold as a box of parts.

The circuit at the center was Heath's patented Ultra-Linear output design, which the company claimed for unusually fine specifications. The tube complement ran heavy: 26 EU7, 26 AU8, 26 AN8, 4-EU8, 6/BG05. It ran from a 117-volt, 50-60 cycle supply drawing 130 watts. Two AC receptacles on the back, one switched and one unswitched, were handy for powering a turntable or tuner alongside the amp. Output taps covered 4, 8, and 16 ohms, and the damping factor was quoted at 10. An export model was available for 115-230 VAC, 50-60 cps, priced on request.

The measured specs were solidly mid-fi for the era. Power response was ±1 dB from 20 Hz to 20 kHz at 14 watts per channel in the 1966 catalog, and ±1 dB from 30 cps to 15 kc in the earlier 1962 literature, so the spec tightened as the years went on. Harmonic distortion was less than 2% from 30 Hz to 15 kHz at full rated output. Intermodulation distortion was less than 2% with 60 cps and 6 kc signals mixed 4:1, and channel separation was quoted as better than 45 dB. Hum and noise figures depended on the input. Magnetic phono measured 55 dB below 14 watts, while tuner and crystal phono came in at 65 dB below. Input sensitivity was 0.00 volts for magnetic phono and 0.2 volts for tuner and auxiliary, with tone controls flat.

The AA-151 was reviewed and advertised in HiFi-Stereo (March 1962, p.24). There, Heathkit's factory performance guarantee, the promise that every kit would meet factory specifications or be made right, was presented as the reason buyers could order with confidence. The same styling concept was introduced across the Heathkit stereo line in 1961 as the AJ-11 tuner arrived. The AA-151 was positioned as that tuner's companion, sharing its charcoal panel and tan case.

The recommended system mates in the Heathkit catalog show how the company expected owners to build out a system: the AS-163 and AS-51 speaker systems, the AS-10, and any of the changers and turntables Heathkit sold, plus the AJ-12 or AJ-32 tuner depending on year.

Two AC outlets, a speaker phase-reversal switch, and a filament balance control round out the feature list. The balance control was a period-appropriate touch, since AC-heated tube filaments were a known hum source and the control gave builders a way to null it out. None of this was exotic. All of it was useful. Thousands of them were built, which is why they still turn up today.

Market Value

┌──────────────────────────────────────────────────────────────────────────┐
│ HEATHKIT AA-151                                                 Nov 2026 │
├──────────────────────────────────────────────────────────────────────────┤
│ High      $2,100                                  Latest            $341 │
│ Median    $320                                    Trend                — │
│ Low       $206                                    Volume           ~2/mo │
├──────────────────────────────────────────────────────────────────────────┤
│ $3,000 ┤                                                                 │
│        │                                                                 │
│        │                                                                 │
│ $1,800 ┤                              .                                  │
│        │                                                                 │
│        │                                                                 │
│        │                                                                 │
│   $200 ┤..    .                                                  .  .  ..│
│        ├─────────────────────────────────────────────────────────────────│
│    vol │█▄    ▄                       ▄                          ▄  █  ▄▄│
│        └─────────────────────────────────────────────────────────────────│
│         2026-04                      2026-06                      2026-07│
└──────────────────────────────────────────────────────────────────────────┘

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