Guitar Amplifiers
The original magazine was about hi-fi, so its guitar category is small, and most of what sits here was not designed as a guitar amplifier at all. The Stromberg-Carlson amplifiers in this group are public-address units with microphone and phono inputs; the larger one, the Signet 70, also has a quarter-inch guitar input and is built around 6550 output tubes, a type guitarists like for its headroom.
That is a familiar story with vintage PA amplifiers. Bogen Challengers, Stromberg-Carlsons and similar units were built heavily and cheaply, and when schools and halls replaced them, musicians bought them. Wikipedia's article on Terry Kath, guitarist of the band Chicago, mentions him preamping a Fender amplifier through a Bogen Challenger in the studio.
If you plan to use one for guitar, do the restoration first. Old PA amplifiers often have tired filter capacitors and may have constant-voltage speaker taps that do not suit an 8-ohm guitar cabinet.
