Hi all. I have a p-bass, boss eq pedal, active Di box. I get how a Di box works. What is the difference between eq & pre-amp? Or are they basically the same thing? I sometimes see Di boxes with pre-amps &/or Eq’s.
Pre-amp is an overloaded term. A pre-amp itself is mostly just a basic electronic circuit that is in most devices that can change the volume of a signal. You’ll hear it used a lot this way (“mic preamps” in mixers and audio interfaces, etc).
It’s also used when referring to the first stage of what you would think of as an amplifier - like your bass amp. The controls on your bass amp for input gain, EQ, drive, and in fact almost anything else that isn’t the final master volume - those are actually part of the preamp. Most (and really almost all for modern amps) of your amp’s tone comes from here.
A preamp pedal is a pedal that contains basically that - but lifted out into a pedal. Often they will improve/color tone like many amps do; usually they have basic EQ features, plus often overdrives, distortions, and other tone modifiers; and many also have integrated DI’s.
An EQ pedal is basically just an EQ without those extra features, usually with more bands; preamp pedals tend to be 3 or 4 band EQ’s.