I am thinking about building a hybrid amp, with a valve/tube preamp. One of the features I wanted was tone control, and I'm trying to decide between three approaches:
First is a tone stack, where the output of the tone stack goes into the preamp tube.
Second is splitting the source signal into separate signals, then using a bandpass filter on each of those to select for certain frequencies, then finally sending the output from the filter to the preamp tube.
Third is something I've thought about, but I'm not sure will work. Instead of changing the source signal at all, I was wondering about using a bandpass filter on the decoupling part of the cathode-bias circuit on the preamp. Instead of just decoupling with a capacitor, I was thinking about a shunt (or parallel) LC circuit that acts as a specific bandpass, which should change the frequency response of the tube.
Does anyone have any experience with any of these, or any good ideas about them? Thanks!
First is a tone stack, where the output of the tone stack goes into the preamp tube.
Second is splitting the source signal into separate signals, then using a bandpass filter on each of those to select for certain frequencies, then finally sending the output from the filter to the preamp tube.
Third is something I've thought about, but I'm not sure will work. Instead of changing the source signal at all, I was wondering about using a bandpass filter on the decoupling part of the cathode-bias circuit on the preamp. Instead of just decoupling with a capacitor, I was thinking about a shunt (or parallel) LC circuit that acts as a specific bandpass, which should change the frequency response of the tube.
Does anyone have any experience with any of these, or any good ideas about them? Thanks!