Troubleshoot your amplifier online
Answer the questions below to find out what's wrong with your amplifier.
On Zen Triode Amplifiers the negative speaker jacks on the amplifier are not grounded. It is referred to as a floating output stage. In areas with high noise, such as WIFI, bluetooth, LED bulbs, smart devices around the home, etc., it is possible for the speaker cables to pick this up like a large antenna. Then you will hear noise or hum from the speakers when the amplifier is turned off.
To solve this you can connect a jumper wire from the negative speaker jack on each channel of the amplifier to ground. Usually a bolt on the power transformer works well as a ground.
NOTE: This will also fix any hum problems with REL and similar subwoofers that use speaker level inputs.