Fisher 550-T (circa 1967–1968)

Type: Solid-state AM/FM stereo receiver
Power: 90 watts music power (IHF)
FM sensitivity: 1.8 µV (IHF)
FM section: 7 ICs, 3 limiters, 2 FETs
Patented circuit: U.S. Patent No. 3,290,443
Meter: d'Arsonval tuning meter with IC-controlled muting

Name: Fisher 550
Brand: Fisher

The Fisher 550-T is a solid-state AM/FM stereo receiver from Fisher's late-1960s lineup. Fisher seems to have marketed it hard for a short window and then superseded it. Almost everything that survives in documentation is the ad campaign, which ran in audio magazines through 1968.

The 550-T delivered 90 watts music power (IHF). Fisher's ads liked to point out that this was enough to drive even inefficient speakers. The FM tuner section used seven ICs, three limiters and two FETs, with IHF sensitivity rated at 1.8 µV. High Fidelity (October 1967, p.51) carried Fisher's own claim that the set was "virtually distortion-free". The ads invited listeners to write the station engineer if they heard any distortion, which implied the receiver would reveal transmission flaws, not add its own. The AM section got serious treatment too, which was unusual for the period. Fisher argued that AM deserved better than the grudging, noisy tuner sections most receivers offered, and the 550-T was designed to make AM listenable even for critical ears.

The d'Arsonval tuning meter is a distinctive feature. It is controlled by a seventh IC used for muting. The 550-T was also positioned as a step up from the 500-T. Fisher's advertising noted that because it had both AM and FM bands, it could pull in twice as many stations.

Beyond the ad campaign, little is documented. No service manual excerpts and no independent lab test reports from the usual audio publications have turned up in the archive. Fisher clearly believed the receiver was a flagship, and their ads called it "as close to the top as you can get without actually being there". It seems to have been quickly overshadowed by later solid-state models.