Altec Lansing 9477B (1974 ~ 75)

A monaural solid-state power amplifier built for professional studio monitoring, released around 1974–75.

Overview

The Altec Lansing 9477B is a monaural power amplifier designed for use in recording studios as a successor to the 9477A. Built around all-transistor circuitry, it was engineered specifically to drive Altec speakers under optimal conditions, with a damping factor of 14.5 tailored for tight control. It supports multiple load impedances—4 Ω, 8 Ω, and 16 Ω—and operates on either 120 VAC or 240 V power supplies, making it adaptable to different regional standards.

Specifications

Rated output130W continuous
Input sensitivity0.8V
Frequency characteristic20 Hz to 20 kHz ± 0.5 dB
Load impedance4 Ω, 8 Ω, 16 Ω
Input impedance15k Ω (unbalanced)
Damping factor14.5
Power requirements120 VAC / 240 V, 50Hz/60Hz
Power consumption20 ~ 250W
External dimensionsWidth 483x Height 178x Depth 216 mm
Weight15.5kg

Design

The 9477B uses a fully solid-state design with transistors throughout all stages and includes Peerless Transformers. Its damping factor is specifically tuned to ensure optimal performance when driving Altec speakers in professional environments.

Context

Developed as a successor to the 9477A, the 9477B was designed for use as a monitor amplifier in recording studios, emphasizing reliability and accurate power delivery in professional audio applications.

Market

One known unit was listed as New Old Stock and in excellent working condition. The original price was ¥245,300 around 1977.

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