Two simple single-Triode EQ circuits
These are sometime overlooked as alternative tone circuits for pre-amplifier designs … the first one, a single frequency cut-only variant, I use as an alternative to the common signal-sucking tone stack found in BF/SF Fender Champs … it allows a 12-position discretely variable Mid “scoop” with Depth control, and allows the gain stage to operate at higher gain, with Cathode bypassing … it’s combines the high gain of a open-gain Champ and the scoop function of a tone stack when Mid is dropped to zero, and Bass/Treb set higher … see my “unleashed Champ” PDF for more details
The second one, allows for both cut and boost (12 o’clock flat) and is commonly used with other frequency bands to produce what became the GRAPHIC Equalization circuit … this should be built into a pedal as the Signal/Noise would be much better than any transistor (Shinei AF-17) or op-amp (Boss GE-7) circuit … just sayin’
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