Two of the most important factors to consider when buying a bass amp are type of amp and amp size. When buying a bass amp, most of the choices come down to differences in price and in the purpose the amp serves.
One of the biggest choices to consider when buying a bass amp is whether the amp is a solid-state or a tube amp. Solid-state amps are typically cheaper and more durable, while tube amps are more expensive and more fragile.
The biggest difference, however, comes in the volume quality of each type of amp. A solid-state amp sounds fine at lower volumes but can lose sound quality at louder, more distorted levels.
A tube amp maintains fidelity at higher volumes and often sounds best when turned up. Many solid-state amps, especially more expensive models, also have enough volume range to avoid losing quality at higher levels.
The size of the bass amp is another crucial concern. A smaller combo amp, which combines all the features of larger, two-piece amp setups into one convenient package, is typically enough for musicians playing in studios or at smaller clubs. A larger, more expensive head-and-cabinet setup produces a more powerful sound, but this is usually only necessary for bassists playing at large venues like halls and auditoriums. Typically, combo amps serve the purposes of most bassists, while a head-and-cabinet combination is only a necessity for serious working musicians.