Editing Instrument amplifier (section)

===Acoustic amplifiers ===
These amplifiers are intended for acoustic instruments such as [[violin]] ("fiddle"), [[mandolin]], [[harp]], and [[acoustic guitar]]—especially for the way musicians play these instruments in quieter genres such as [[Folk music|folk]] and [[Bluegrass music|bluegrass]]. They are similar to keyboard amplifiers, in that they have a relatively flat frequency response and avoid tonal coloration. 

To produce this relatively clean sound, these amplifiers often have very powerful amplifiers (up to 800 watts RMS), to provide additional [[Headroom (audio signal processing)|headroom]] and prevent unwanted distortion. Since an 800-watt amplifier built with standard [[Class AB]] technology would be heavy, some acoustic amplifier manufacturers use lightweight [[Class D amplifiers|Class D]], "switching amplifiers".

Acoustic amplifier designs strive to produce a clean, transparent, ''acoustic'' sound that does not—except for reverb and other effects—alter the natural instrument sound, other than to make it louder. Amplifiers often come with a simple mixer to blend signals from a pickup and microphone. Since the early 2000s, it is increasingly common for acoustic amplifiers to provided digital effects, such as [[reverb]] and [[Gain compression|compression]]. Some also contain [[feedback]]-suppressing devices, such as [[notch filter]]s or [[parametric equalizer]]s.<ref>Note: Acoustic amplifiers should not be confused with the amplifier brand name ''[[Acoustic Control Corporation|Acoustic]],'' whose products are still available in the used equipment market.)</ref>

Acoustic guitars do not usually have a built-in pickup or microphone, at least with entry-level and beginner instruments. Some acoustic guitars have a small [[condenser microphone]] mounted inside the body, which designed to convert acoustic vibrations into an electrical signal, but usually they do so from direct contact with the strings (replacing the guitar's bridge) or with the guitar's body, rather than having a membrane-like general-purpose microphone. Acoustic guitars may also use a [[piezoelectric]] pickup, which converts the vibrations of the instrument into an electronic signal. More rarely, a magnetic pickup may be mounted in the sound hole of an acoustic guitar; while magnetic pickups do not have the same acoustic tone that microphones and piezo pickups can produce, magnetic pickups are more resistant to [[acoustic feedback]].