the potentiometer sucks and is noisy. same thing happens with really crappy resistors that have been heated up. they can tend to act somewhat like inductors and eat up quickly changing currents (high freqs)
iirc, if anything, a current divider instead of a voltage divider (parallel instead of series) would be better, i remember it being recommended to get rid of hisses. or maybe that is specifically to not affect impedance
iirc, if anything, a current divider instead of a voltage divider (parallel instead of series) would be better, i remember it being recommended to get rid of hisses. or maybe that is specifically to not affect impedance