The amp operates with a single 12AX7 tube in the preamp and uses a solid state power amp. The FX loop enables you to put your time based effects (or Phasers, Flangers and Choruses) behind the drive section and keep the effects sharp and not prevent them from being too muddy. The CLEAN channel can take pedals really well, which makes it flexible and a great little companion for many situations where your “big” head is just not sensible. The amp has a speaker out rated at 8?, but can also be operated at 16? with less power. Careful, the amp is small, but loud… its 20 Watts can be quite a handful. If you want to practice quietly, use the built in headphone out with speaker emulation. The icing on the cake is the BLUETOOTH connectivity. Easily connect with your BLUETOOTH enabled device and play music through the BantamP. This is great to practice with PlayAlongs or to learn songs. Features Preamp circuit: JFET+ 1 x 12AX7 Power amp: CLASS D Channel mode: CLEAN / OD Amp power: 20W(RMS) Aux in function: Bluetooth music playing Bluetooth version: 4.0 Input AC 110-240V 50/60Hz OUTPUT DC18V/2.0A Size 163mm*110mm*140mm