[Stephie Bench]

Hey Patrick,

Was thinking about your musings on a tone stack. On the LC 400Hz mid circuit. A small inductor 1.6mH, only has a reactance of around 5 ohms at 400Hz. The cathode Z is in the hundreds of ohms. Since Q in a series circuit is Q=X/R, you can't develop enough effective resonant Q to be useful. Might save you some disappointing results. I do like the concept of the cathode series tank, but note that will give you a boost only, not boost cut, unless you do a little switching. What might be cool is to implement all the tone stack that way. It might keep the interaction down too.

Also note that significant boost is difficult to achieve with RC only with your proviso that 2 octave away has essentially no change in response. You'll get at least a dB or so change that close. (Thinking of the 100Hz boost vs 400Hz no-boost.

Cheers,
Stephie