MARSHALL: 1974X AKA the Marshall 18w one knob tone controls

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Another simple one knob tone control, this time from the Marshall 18w amplifier, or the model 1974x, whatever you prefer…    Marshall used two different tone controls in the amp.  A lot of folks build the 18w lite, which is just the normal channel of the amp, and they often use the trem channel tone … Read more

FENDER: One knob tone control

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This is the classic single-knob tone circuit made famous by a number of Fender amps—most notably the 5E3 Tweed Deluxe.  Despite not inventing it, Leo must have thought that he nailed it when he first dropped this into a guitar amplifier: it’s simple, clever, and very musical.  Despite using only a handful of parts, it … Read more

CTS Speakers

ETI 1974 08 p89 a5c590507322

Chicago Telephone Supply (CTS) originally built drivers for telephone network signaling and tone generation. By the late 1950s they expanded into loudspeakers, supplying the booming tube-amp market.  Their speakers, often marked with the EIA code “137,” were used extensively by Fender, Ampeg, and many other amplifier companies from the 1950s through the 1970s. Early CTS … Read more