Preamp Purpose

[Dodgeviperracer]

What purpose does a preamp serve and is it totally necessary to complete your rig? I've never really been knowledgeable about amps and preamps, cabs and how they should coincide so help me out.

[prd004]

The signal from your bass is a high impedance output. The preamp boosts that signal to line-level which is what your power amp needs.

All the other bells and whistles in your amp, EQ, FX loop, whatever your particular amp has, are all part of the pre-amp section, but they're not really necessary. (Technically, that is, but you are sure glad it's there)!

[m.oreilly]

if you have a combo or a 'head' and a cab, you already have a preamp (the tone/initial volume controls, effect loop, etc.). if you purchase a power amp, you would also use a separate preamp (with the tone/initial volume controls, effect loop, ect)

[MakiSupaStar]

The preamp is the 'sound' that makes the combo of your bass and rig unique. It's the amp's flavor and tone while your power amp is what actually drives that sound to your speakers. It's what creates that Ampeg/Aguilar/SWR/GK or whatever sound. If you don't think that's important then, no it's not important.

[Implosion]

Originally Posted by MakiSupaStar

The preamp is the 'sound' that makes the combo of your bass and rig unique. It's the amp's flavor and tone while your power amp is what actually drives that sound to your speakers. It's what creates that Ampeg/Aguilar/SWR/GK or whatever sound. If you don't think that's important then, no it's not important.

Well not totally. The design purpose of a PA-type power amp is to reproduce the signal as clean as possible. But in case of an all tube power section the saturation effect is usually desirable. For instance to achieve the "Ampeg sound" you need an all tube power section driven into saturation. Also the non-tube power sections may have tonal design goals. A good example would be the voltage rail design in GK power amp sections.

[Sartori]

As has been said, it's the part of an amp that boosts the signal to something the power amp can use. Also usually in a preamp are the EQ controls with which you can fine tune your sound.

Almost all bass amps have a preamp. The EQ section is not strictly necessary, and there are a couple amps that have very minimal preamp controls.

[MakiSupaStar]

Originally Posted by Implosion

Well not totally. The design purpose of a PA-type power amp is to reproduce the signal as clean as possible. But in case of an all tube power section the saturation effect is usually desirable. For instance to achieve the "Ampeg sound" you need an all tube power section driven into saturation. Also the non-tube power sections may have tonal design goals. A good example would be the voltage rail design in GK power amp sections.

You bring up some good points. I run a pre/power rig. I actually forgot to consider tube power or tonal qualities of the power section of regular bass head.

[BurningSkies]

Here's the preamp porpoise!

[MakiSupaStar]

Originally Posted by BurningSkies

Here's the preamp porpoise!

hahahaha.

[Sartori]

Aww, the Preamp Porpoise is so cute!