I'm putting together a little 4->1 active audio mixer circuit for a friend of mine. The circuit is basically just RC RF filter on the input, dc blocking capacitor, potentiometer, then into an active summer and a "zero impedance" output stage for driving cable that has a capacitive feedback loop to keep the opamp stable and then a second feedback loop around the output resistor for stability driving capacitive loads.
There's not much room in the enclosure, so I'd like to use one of those tiny "China Special" boost converters to step the voltage from a 9V up to 18 to get more headroom for the circuit.
The output of the switcher isn't particularly clean - looks like maybe a hundred mV P2P of 500kHz ripple while lightly loaded on the output. I'd like to clean this up a bit before feeding the op amps, but I don't really want to linear post regulate. Is there a good way to do this? Maybe an RF choke in line with the switcher output and then an electrolytic right at the feed to the opamps?