The 5150 and 5150 II are both guitar amplifiers produced by the company Peavey.
They are known for their clean tones and powerful performance.
The main difference between the two is that the 5150 II has an updated preamp circuit that provides more gain and a more aggressive distortion tone compared to the original 5150.
Also, the 5150 II also has a more versatile tone-shaping capability, as well as an effects loop. However, the overall power, speaker configuration, and basic features remained the same.