Autocorrect tried to help, but in fact I have a hum issue that seems to have popped up only recently. When it first arrived everything seemed to function as should. The HUM is definitely a ground HUM type of tone which seems to attenuate all the other signals.
Except for noise, all other segments in the pyramid have the same hum even when no other pad is being touched.
I’ve swapped AC adapters but doesn’t seem to help.