Purifi 3-Channel Amp has introduced radio Interference

[DMSO]

From Audiophonics:
"It's normal without XLR connected you have a little noise. You hear this sound because the input are in high impedance. You dont have this problem with Ncore because Ncore have 10k resistor grounded on the input, not the purifi amp."

Did audiophonics say this? Nice - I had a suspicion looking at the little PCB they use on their Ncore amps, but this settles it. Building an Ncore based amp and want to get rid of that hum when nothing is connected. Will put resistors in place too. Thanks for this!