Percy,
This is pretty standard on a whole lot of devices at any price point.

You are removing power from a device which is connected to a live amplifier. The addition or removal of power may not, usually isn't, quiet, and it's going to cause the boom.

Turn the amp down every time.

Gary


I'm blessed watching God do what He does best. I've had a few rough years, and I'm still not back to where I want to be, but I'm on the way and things are looking far better now than what they were!