Hey folks. I'm pretty sure some of you here are circuitry buffs and maybe you can help me out! I'm trying to design and build a graphic equalizer which can also change the center frequency and bandwidth of the passbands for the transfer function. (Making changing the sound quality of my guitar output very flexible, yes? =)
I have the choice to do the following...
Firstly, initially I thought perhaps I should use op-amps for the equalization part. But it occurs to me that if I can superimpose a band reject filter with a bandpass filter, perhaps I can forego having to power the circuit if I'd used op-amps. Furthermore, the amplication of the voltage would happen in the guitar amp itself anyway so perhaps it is better.
Either I can put the filter before the eq, or the eq before the filter. If I were to have amplified the input voltage first, perhaps we can get a better one-to-one relationship on output (ie less noise since it's scaled up). Or maybe I should amplify it, filter it, and then scale it back down? And also, I suppose I'd have to use two different sets of inductors and capacitors if I were to superimpose a bandpass and band reject filter's output voltages, yes? (I was looking at the schematics for both and it dawned on me that if I were to just take the voltage across the resistor, capacitor, and inductor, it would just be the input voltage without a transformation, hehe, silly me...) At any rate, can anyone shed some light?
Another question I have which some may somehow know, else I will continue my research is the following...
Is the voltage frequency the same as the mechanical frequency, and the same as the sound frequency from the guitar strings thru the pickup? I would assume so since the string would oscillate a magnetic field at the same frequency it is mechanically oscillating.
Thanks for any help! Can't quite find a board as quick and nice as this for this stuff, will keep looking! =)