Never fully understood what the pre amp was for. I am am currently in the market for a new amp, and see a bunch of pre amps in my search, however, wanted to some clearification around the purpose of the Pre amp and pro's and cons of it. Any help would be great.
"What's the point of callin' shots;
This cue ain't straight in line.
Cue ball's made of styrofoam
And no one's got the time." (Garcia/Hunter)
The idea comes having a mixing board with it's own amp and speakers.
You can plug your guitar directly into the board, but it sounds sterile.
A basic guitar preamp colors the sound to make it sound better.
It's common for acoustic guitars to have an onboard preamp for this.
Preamps for electric guitar are based on having a separate power amp and speakers.
Older guitar preamps had only one or two channels. Some tube preamps stacked the two for a third lead channel.
The next innovation was to add effects, and then a decade or so later they added speaker and amp simulations.
Most modern preamps are all digital, although some high-end analog or tube ones are still around.
The latest thing is to add a tube, which was done decades ago.
One real example would be a Line6 AX2 combo versus the Line6 POD preamp.
Most prefer the combo because they perfected the sound based on the speakers and amp in it.
The sound of the POD is dependant on the external amp and speakers used.
The best way is to get the Line6 combo, which has a preamp output you can plug into a mixing board.
Of course, getting only the preamp (POD) is a lot cheaper.
On a final note, tube-only preamps usually become collector items.
They are usually more expensive, use fewer readily available parts, and are easier to repair.
1 watt of pure tube tone - the Living Room Amp!
http://www.naturdoctor.com/Chapters/Amps/LivingRoomAmp.html
Paper-in-oil caps rule!
A preamp would boost your guitar signal from the pickups which allows for matching impedance's and ohms. Essentially it boosts your signal. In a guitar amp you plug your guitar into the preamp which boosts the signal to match the power amps input, then the power amplifies the signal to the speakers. This is simply put without getting technical.
With so many different ones on the market these days it would be hard to say one is better than another. What works and sounds good to me might not work or sound right for you. Because everyone has their own idea on what the want for tone. I use tube preamps and tube power amps for the bases of my tone. When creating a great sounding signal chain it takes more just those units to make it complete.
I use preamps rather effectively in my setup by driving a 100 watt tube amp into a dummyload, using it basically as a preamp. Then I combine numerous equalizers, tube effects processors, tube power amps, attenuators, and celestion speakers. From experimenting, trial and error with both solidstate and tube equipment, my choice was with the equipment I know I can get my guitar to talk many different language's or styles.
If you look throught this part of the forum you'll find were I've posted an image of my setup. I hope it gives folks ideas on how to build a great sounding signal chain. I would recommend trying a few different types out and decide what works for you. Do you an idea as to what you want as far tone your looking for. Like being original or imitating someone else's.
Joe
