Guitar amps - electric vs acoustic

[Electron Tornado]

What are the differences between an electric guitar amp and an acoustic guitar amp?

[Morocotopo]

OK, no expert here but I´ll try:

- Speaker: electric has limited high freq response, acoustic needs full range response to sound good, that´s why many have tweeters.
- Circuit freq response: most electric amps have scooped mids, most acoustic ones have flatter response.
- EQ: electric is usually passive, acoustic is usually active and with different freq. centers. Also acoustic can have a tunable notch filter to eliminate feedback.
- Input: Acoustic needs very high impedance for plugging a piezo directly (10 Mohms), can also have a balanced input, usually two channels, one for piezo and one for mic/mag or something like that.
- Distortion: Don´t!! Acoustic amps try to minimize it, although some are more successful than others... Electric amps exist to add it to the sound, whether obvious or subtle.
- Technology: I don´t know of any tube acoustic amps, the extra weight and loose damping doesn´t help the acoustic sound or player´s hands.

An acoustic amp is essentially a little PA in a box. Designed to reproduce and not produce the sound.