Amp Simulator
Although it is not really an effect in the sense it changes the sound before it enters the speaker, it is found more and more by digital guitar effect units.
An amp simulator does what it says: it simulates a guitar amplifier, mimicing mostly famous guitar amps by adding a combination of effects mentioned earlier (like boost, distortion).
The sound output from an amp simulator can be used to be directed to a normal amplifier, PA system etc.
Some advantages of using an amp simulator are:
- easy switching between different simulated guitar amps
- usually cheaper than the original (let alone the sum of possible simulations)
- effective at low volumes (some amplifiers only produce their best sounds when cranked up loud)
- effective in 100% microphone-free applications -- can output direct to a mixing desk, DAW or PA.
- it sounds good with very clean amps (like Fender Twin Reverb)
The main disadvantage is that some people consider the simulated sounds inferior to a real amplifier. Due to it is not transparent may not sound well with dirty amps that provide their own tone.
When used in conjunction with a real guitar amplifier, there's a complicated interplay between the tone created by the real amp, atop the tone create by the simulation. It makes more sense to use amp simulation with a PA amp or a HiFi amp, designed to faithfully reproduce its input: the amp simulation provides tone; the real amp provides volume.
