A Class AB power section is based on the notion that music is a waveform and linear in nature – i.e. you only get a +ve section followed by a -ve section, you never get a +ve & -ve occurring at the same time. In a Class AB amplifier, the input signal is split into the +ve and the -ve sides of the waveform and each respective part is sent to a separate tube or tubes and amplified accordingly
Allows you to drive the output stage of the amplifier harder at reduced output levels should you need to use the unit in situations where full volume is not appropriate.
On-board studio quality reverb. Reverb gives you a sense of the space that you are in. A dry guitar signal can sound a little dull. Adding the right about of reverb provides the guitar signal with ambience and brings it to life.
FX loops are important as they allow you to add effects to the signal path in a specific place between the pre-amp and the output section on an amplifier. This is where FX loops are important as it allows you to put time-based FX after the distorted pre-amp section. For example, delayed distortion sounds different to distorted delay – try it.