Q: I have a great preamp. Do I need a great power amp as well?

 I have a fantastic preamp and it makes all my vocals sound big and fat. I wonder if I should have an equally great power amp as well, so that everything I monitor sounds HUGE!

By David Mellor, Course Director of Audio Masterclass

There are basically three types of microphone preamplifier...

• Badly designed


• Solid state


• Vacuum tube

If your preamp is badly-designed, then it will be noisy, distorted and have a poor frequency response. It will sound bad so don't use it.

Some preamps are not quite as well-designed as they could be. They might be a little bit noisy for instance. You can still make acceptable recordings, as long as you take care to get a good strong signal from the microphone, which will overpower the noise.

When preamps are well-designed, as they should be since preamp design is no longer rocket science, a solid state preamp will take the signal from the mic and amplify it, adding and subtracting nothing. It won't make your sound better or worse. You'll hear it as it is.

(A solid-state amplifier uses transistors as its active devices instead of vacuum tubes.)

A tube preamp can add 'warmth'. Warmth is pleasant-sounding distortion. Distortion isn't always bad. Warmth is subjective, so you will have to decide for yourself which warm-sounding preamp you prefer.

(By the way, tubes don't always have to distort, it's just easier to make them distort nicely than it is with transistors.)

It's the same with power amplifiers...

You can have the same three classes of power amplifiers.
However for recording, you will always prefer a solid state power amplifier.

Why?

Because it adds and subtracts nothing from your sound. It just drives the speakers.

You could buy a warm-sounding tube power amplifier. It would make the sound from your monitor loudspeakers very full and fat, really nice to listen to.

But that fullness and fatness wouldn't be on your recording. So there wouldn't be any point.

There's an argument to say that while you're recording, your musicians will perform better if they hear great sounds coming from the speakers.

But while your mixing, you want the truth and nothing but the truth!

You need a high-quality, high-power solid state power amplifier.

So choose your microphone preamplifier to suit your needs. But always choose an accurate power amplifier for when you're mixing.

Publication date: Friday July 23, 2010
Author: David Mellor, Course Director of Audio Masterclass