HF89

About the HF89

The Eico HF-89 is a stereo tube power amplifier produced by EICO (Electronic Instrument Co.Inc.) in the United States around 1960-1961. It features a power output of 50 watts per channel into 8 ohms, utilizing a tube complement of 1 x ECC83, 2 x 6SN7GTB, and 4 x EL34 tubes. The amplifier has a frequency response from 5 Hz to 100 kHz, total harmonic distortion of 1%, a damping factor of 12, and an input sensitivity of 0.55V. It supports speaker loads from 4 to 16 ohms and has a signal-to-noise ratio of 90 dB. The HF-89 is housed in a metal chassis measuring approximately 15 x 11 x 6 inches and weighs about 37.5 lbs. It was originally50. The amplifier is noted for its flat power response, low hum, and solid, effortless sound quality comparable to more expensive models of its era. It requires external speakers and operates on 117V AC power. The design includes multiple feedback loops and a voltage doubler power supply, contributing to its performance and reliability. The HF-89 is considered a classic tube amplifier with a reputation for good sound and build quality for its price point.