The guitar preamp is the most important part of your amplification system. Unless your guitar sucks, a good guitar preamp means a good final sound. The guitar preamp takes the thin output of your guitar and give it life. It is the DNA of the sound, so usually bad sound means bad preamp settings (or even bad guitar preamp).
There are two different kind of guitar preamps: multi-channels preamps and programmable preamps.
In a multi-channel preamp, each channel (usually two or three channels) is designed to target only one specific kind of sound. Each channel does its job flawlessly, but don’t ask it a sound different from what has been thought in the design stage. A classic example is a Marshall amp with three channels: “Clean”, “Overdrive 1” and “Overdrive 2”..
2 channels preamp (clean and overdrive)
Programmable preamps have a digital system embedded; with it you can create, edit and memorize a big number of preset sounds. For each preset you can set different values of volume, gain, overdrive values and give it a name, such as "lead guitar", "clean", "supermetaloverdriveholocaust", and so on, you get the idea.
During a live concert, with a multi-channel preamp you can only switch between the channels the amp has, so usually you can have two or three different sounds, that most of the time are enough. With a programmable preamp you can activate one of the 100000 preset you created the night before. This give you a lot of flexibility; if you play with different bands that require different sound, or you need a lot of disparate sounds effects because you play in an Ozric Tentacles tribute band, this is a good solution. Obviously managing of a programmable preamp requires time and tuning, because the options are many.
Usually a multi-channels preamp has a sound quality better than the programmable preamp. The reason is that the electronic components of a multi-channel preamp have been designed to do one only thing, but in the best way. So the circuit of the clean channel and its vacuum tube is tuned in order to have the best possible clean sound; the same for the overdrive channel. The tubes of the programmable preamps have to deal with a huge number of different sounds, so they are mounted in a general purpose circuit.
Multi-channel guitar preamps: better quality sound, low number of sounds (usually 2 or 3), easy to use.
Programmable guitar preamps: a huge number of different sounds, flexibility, they require the right setup.
Is this helpful?
Share with your fellow guitar players
Stay updated and get free ebooks
Subscribe to the free newsletter and download chords and scales ebooks: click here to stay updated