Guide to getting and playing better gigs
Effects
Compression
is an automatic level control often used in recording to make instruments and vocals louder or softer in order to emphasize or de-emphasize them. It's used with a guitar to increase sustain.Reverb
creates the effect of the multiple sound reflections that would naturally be produced in a playing environment.Tremolo
modulates the signal, similarly to turning the volume rapidly up and down.Delay
is an echo effect that samples a sound and then replays it one or more times.Equalisers and Speaker Simulators
These effects can be used on their own, to tailor solo or rhythm sounds, or with overdrives to give more control than you usually have with the overdrive tone control. For example, you could use heavy distortion, and use equalisation here to cut middle for a heavy sound, or tailor the highs for a creamy, yet "bitey" Santana sound, etc.Speaker Simulators:
A typical guitar speaker cab isn't designed to faithfully reproduce the sound presented by the amplifier. Unlike hi-fi systems and front of house systems that strive for a wide bandwidth and uncoloured sound, guitar speaker cabs are an important part of the sound creation process. Without a speaker simulator, you're likely to get the best guitar sound through front of house by using one or more microphones around your guitar amp. The quality of speaker simulators varies enormously. I've heard some which seem to strangle the sound, while others enhance the sound, even when used in conjunction with real guitar speakers. Common options are choice of cabinet type and speakers, closed or open back, microphone types and positions, and a mix of direct vs simulator.Speaker simulators are mostly preset, and highly tailored equalisers to emulate speaker cab resonances, and microphone techniques. Some include other subtle effects, such as short delays, as well. Placement is not as crucial as you might think. For example, most recorded sounds use a microphone in front of a speaker cab, then studio effects, such as equalisation, chorus, delay, etc applied afterwards.
On the other hand, when you play live, and are using a variety of effects through a stage power amp and speaker cab, you might want to use the simulator here only for the purpose of feeding the mixing desk (who apply their own delay and reverb for the front mix). You could bypass the simulator on stage, and apply just enough delay/reverb to give a natural on-stage sound.