use a mic preamp before the first circuit. the low impedance of the tone control circuit won't have an effect on anything connected to it's input, because the first op amp isolates the input. the first circuit has an input impedance of 22k, because the - input of the op amp is a "virtual" ground. the second circuit has an input impedance set by the input termination (in this case 100k), but would be theoretically infinite if the resistor weren't there (with a TL072, it's 10^13 ohms).