Vintage Preamps and Tube Preamps

A preamplifier, or preamp, is a part of the signal chain for using a loudspeaker to play audio. It adjusts the incoming signal from the source and prepares it to be boosted by a power amplifier. A preamp that uses tubes will have that classic warm, slightly distorted tone that appears in rock, blues, jazz, and many other genres.

What does a preamplifier do?

A preamp is necessary to transform a raw source from an input into something that can be played out of a loudspeaker. It alters and increases the power of the signal so that it can become audible. The preamp switches between different inputs and applies effects and equalization. In some models, it is combined into one unit with an amplifier, which is called an integrated amplifier. Generally, the quality of separate models is higher because each can specialize and make full use of its cabinet space. It is best to get a matched set from the same manufacturer to ensure that they will work well together.

What do you use a preamp for?

You can use a preamplifier for live play as well as recording. For live play, some instruments and microphones include their own pre-amp, but often you can purchase a separate one if you want a particular tone. For studio use, there are two main options. The preamp can come directly before a recorder to alter the tone if you want to record directly to a digital memory space. Otherwise, you can use sets of microphones on each instrument positioned right in front of its loudspeaker. This might be more desirable for a guitar, for example, to capture realistic reverb and to preserve a set of effects from a combination of power supply, preamp, power amp, equalizer, and pedals.

What kinds of sound can a stereo preamplifier create?

There are essentially no limits to the range and variation of expression from a tube preamplifier. Guitars especially will tend to have several pedals and other alterations to the tone before it reaches the amps, but the preamplifier still has a lot of influence on the audio. The pleasing harmonic distortion from the vacuum tubes forms an excellent baseline tone for just about any application, and the audio from the stereo can become more distorted or even overdriven without clipping. It has the capability to provide a clear and neutral audio tone, especially with well-informed use of equalizer settings as well as the right pedals and boxes.