Fisher 601 (1967)

The Fisher 601 is a solid-state integrated amplifier introduced in 1967 at a price of $179.95. It was Fisher's mid-1960s answer to the transistor transition. It is an all-silicon design rated at 55 watts per channel into 8 ohms, with a frequency response of 20-20,000 Hz. The front panel has a speaker selector switch. The unit measures roughly 14½ inches wide, 4½ inches high and 10 inches deep, and weighs just under 23 pounds.

What's known about the 601 comes mostly from period advertising and restoration shop listings. Detailed reviews are thin on the ground. Fisher's own ads from late 1971 pushed the 601 as a companion to their CP-100 decoder for early quadraphonic playback. They noted that the amplifier could create four channels from two-channel material via an external circuit, but the 601 itself is a stereo integrated amplifier. HiFI-Stereo (July 1971, p.2) ran Fisher advertising that positioned the 601 as "expensive, but not very expensive" next to their 701 true 4-channel receiver, which had debuted the year before at $699.95.

The record has one spec conflict. Input sensitivity is listed as both 1 mV and 3½ mV (fmtvintage). The page doesn't pick one. The other facts - power, frequency response, solid-state construction and dimensions - are the same across both sources.

Known specifications:

Power output: 55 W per channel (RMS per fmtvintage; "maximum" per Radiomuseum) at 8 ohms
Frequency response: 20–20,000 Hz
Circuitry: all silicon transistor, solid state
Dimensions: 14.6 × 4.5 × 10 in (14½ × 4½ × 10 in)
Weight: 22 lb 13 oz (10.3 kg)
Original price: $179.95 (1967)

No current market values, common failure modes or detailed circuit topology have been documented. The 601 does appear on fmtvintage.com's list of amplifiers they have worked on and restored, which suggests the unit is serviceable and that restoration specialists have encountered it.