The NUX Mighty BT-20 practice amplifier is a great sounding practice amplifier that doesn't require a mobile phone. You plug it in and sounds great straight away. You can also save your favorite channel settings on each of the 8 presets. An 8" speaker delivers great tones for practice at home. It's great to see a fully functional practice amplifier that doesn't require any pedals and can be used at any volume with great results.