Phono Pre-Amp Audio Amplifiers
Phono preamplifiers are a common component of many home Hi-Fi setups. While some turntables have the preamp built in, others rely on a separate phonograph preamp. A turntable preamp is especially useful when you aren't using a dedicated phono amplifier but instead want to use a general amplifier for all your components. Just like with any other piece of stereo equipment, your most useful tool for choosing a phonograph preamp is knowledge. The more you know about turntables and amplification the easier it is to make the decision about what you should buy.
How Does a Phonograph Work?
At base, a phonograph is a very simple device. You run a needle along a spiral track on a spinning disk, which then vibrates to produce sound. What happens is that there are minute variations in the track, which are what cause the needle to vibrate and produce sound. The key to understanding record players and turntables comes from the realisation that they can only work as long as the needle moves at a constant speed. If it spins too fast, the pitch rises; if it spins too slow, the pitch falls. Both direct drive and belt-driven turntables operate at a constant speed no matter where the needle is on the record.
Why a Pre-Amp?
The biggest reason for using a preamp is that turntable needles are very small and do not move very much when they vibrate. This means they don't produce a lot of sound. A preamp picks up what little sound they do produce and amplifies it to the point that you can use it with a standard amplifier. The reason you don't just put it directly into your phono amplifier is that any amplifier can only boost a weak signal so far. Amplifying the stronger signal from the preamp is much easier than trying to amplify the signal from the needle in one stage. Some turntables come with a preamp already built-in, while others require an external one.
Tubes or Solid State?
The biggest question for many people when it comes to choosing a preamp for their turntable is whether to go with a tube model or solid state. Each choice comes with its own set of benefits and tradeoffs, so it's worthwhile to put some thought into it before you spend the money:
- Solid State: The biggest advantage of solid state is price. Solid-state preamps are generally less expensive to buy and maintain than tube amps. They are also smaller and use less power.
- Tubes: Tube preamps represent one case where older analogue technology is still able to give digital a run for its money. The reason is simple: tubes provide a certain warm tone that solid state can't really match.