ZERO hum and noise.

Mine makes this weird noise, replacing the ac adapter might work though.

The other reviews are spot on with this item, it picks up cellular traffic frequently and gives you a static beeping noise

They work great because they block out unwanted background noise and sometimes that ability overrules all other requirements

The push button in back isn't as convenient especially since it makes a loud noise when the power is switched on or off while the volume is still turned up.

intermittent static noise

Mine makes this weird noise, replacing the ac adapter might work though.

To avoid unwanted pops and thermal noise, suggest let the tubes warm up for a minute or two before jack-in and jack-out before turning the unit off.