In short: its a really awesome analog amplifier. For 50$ not getting one is just stupid.
Details: this is a great amp head in its own right and sounds better than allot of full tube heads I heard and better than all of the digital stuff by a good margin.
Gain 1. Goes clean just like a tube head especially if you roll back volume on guitar. Picking hard creates smooth breakup into crunchiness.
Gain3. Crunchy. Think AC/DC highway to hell.
Gain 6. Distorted. Good for hard rock rythm chops.
Gain 10. Face melter. Thick. Fluid. With tons of sustain but clean and clear not fuzzy or mushy. Think van halen/malmsteen/iron maiden/megadeath guitar solos.
By using the am Amplug cab you can hook up pre gain stage effects like compressors. Wah pedal etc. By using aux cable and a small to big converter u can hookup the output to reverb/delay/chorus and then iether to headphones or any speaker/aux.