Much of the time, keyboard players will amplify their keyboards by connecting them through the PA system and will have them fed back through the monitor or foldback speakers so that they can hear what they are playing. However, the alternative to this is to have a dedicated keyboard amplifier which needs to be a powerful amplifier with good tonal variation and clear crisp sound.
Keyboard amps generally need little or no effects on-board as today's modern keyboard sounds have reverb, delay or chorus built into the sound patch. The objective is therefore to choose an amplifier that produces an accurate and natural sounding amplification of the sound source. An added benefit would be to select an amplifier or combo that has the ability to add a speaker extension cabinet. This would allow the extension cab to be placed elsewhere on the stage as a monitor reference for the drummer or guitarist.