Stromberg-Carlson
Stromberg-Carlson began in 1894 as a Chicago telephone maker and moved to Rochester, New York, where it built radios, televisions and, after the Second World War, high-end audio. The archive's two Stromberg-Carlson amplifiers are both public-address units: the 70-watt Signet 70, also labelled SAU-70, built around two 6550 output tubes and fitted with microphone, phono and guitar inputs, and the 25-watt AU-58B, known mostly from its nameplate.
The Signet 70 listing illustrates a common risk: its seller fitted 6L6GC tubes in place of the specified 6550s. The two are not equivalent, so check the tube complement against the original specification before using an amplifier like this.
See the company history page and the Stromberg-Carlson maker page.
