Download a 24pp pdf with schematics and technical information regarding all AWA-brand vacuum-tube broadcast audio amplifiers circa 1967: DOWNLOAD: ABCstudioEquipment…
PS dot com reader Paul R. was kind enough to send us a scan of "Audio Anthology," (ed. C.G. McProud)…
The original Williamson hi-fi amplifier schematic as published in "Wireless World" magazine (UK) May 1947. The Williamson amplifier is…
Download a four-page article from "Radio & Television News" 4/1956 regarding the Mullard 520 power amp: DOWNLOAD: Mullard_520_amp American industrial…
From some 1957 issues of "Radio and TV News," an electronic-serviceman's publication, comes this collection of American Hif-Fi home audio…
Download the fifty-page 1940 PRESTO RECORDING CORP catalog: DOWNLOAD (part 1): Presto_1940_Cat_1 DOWNLOAD (part 2):Presto_1940_cat_2 Products covered, with text, some…
Download a three-page article from Electronics World "Hi Fi Annual & Audio Handbook 1960" which details the construction of a…
QST magazine is the monthly publication of the American Radio Relay league (h.f. ARRL). ARRL has published QST since 1915. …
(image source) The RCA OP-6 'Portable Amplifier' is one of a handful of truly visually-iconic vintage mic preamps. The OP-6…
Circuit for a simple bass/treble parametric equalizer that uses no inductors. Could be a useful piece. Not sure if 250k/500k…