From the October 1953 edition of RADIO ELECTRONICS comes this report on an exceptionally powerful EQ circuit as-found in the then-new Bogen DB20 amplifier. The circuit uses no special parts and promises extremely wide-range control. R11 is odd, i’m not sure why that is present. I’m thinking that this might make a good EQ circuit for the Berlinetta DJ console…
One reply on “Bogen DB20 Equalizer Circuit circa 1953”
I think that R11 and R14 form a voltage divider, so R11 is only effecting the value of the B+ voltage for the tone control (and the preceding stages).