Hum eliminator - crazy idea?

[redelephant]

There's a whole bunch of powersupply cancellation techniques discussed at 'tubelab.com'
Really simple too, basically injecting (using a capacitor) powersupply ripple into the signal stage in the correct amount and phase will cancel out ripple (and all harmonics)

[kg]

yeah, this idea has been around a long while. iirc there's mention of antiphase hum injection in the RDH.

seems more trouble than it's worth