few questions
 

i'm a bit new at parts of the guitar. i have a few questions.
1. whats a pre-amp? and what are they're uses
2.what is an ABY box?
3.what is an amp head? and what are they're uses

1. A pre-amp, in most cases, is the part of an amplifier that controls the tone and overall volume of the amplifier. In the case of a guitar amp there are usuall three components:
Pre-amp - volume, tone, reverb etc.
Power-amp - actually supplies the power
Speaker enclosure - self explanatory

2. An ABY box allows a musician to route a single instrument to two different amplifiers and switch between the two at will

3. an amp head is simply an power amp/pre amp combo seperate from the speaker enclosure. Ever see someone playing through a stack? an amp head is the big rectangular box on top of the cabinet with all the knobs on it.

thaks.that helps me a lot.much appriciated