- Find out how preamps and amps differ from each other.
- Discover which preamps and amps are best to use (and why).
- Plus, check out this handy guide on types of guitar amplifiers!
Preamp vs. Amp: What’s The Difference?
A preamp strengthens your guitar’s weak output signal to an audible level, while an amp boosts that line-level signal even further (so it can be projected through speakers).
| Preamp | Amp | |
| Function | A preamp is a device that amplifies a weak signal from a microphone, instrument, or other audio source. | An amplifier (amp) is a device that increases the power of an audio signal to drive speakers or headphones. |
| Common Applications | Preamps are commonly found in recording studio setups, such as audio interfaces. | Amps are commonly found in home audio systems, live sound setups, and guitar rigs. |
What Is A Preamp, And What Does It Do?
The primary function of a preamp is to boost your instrument’s output signal up to ‘line level’ – meaning an audible level, which is easy to apply compression and effects to.
A pure instrument signal typically sounds weak, unclear, and inconsistent in perceived volume. This is particularly evident, for instance, when you plug a guitar directly into an audio interface. Therefore, a preamp can raise an instrument’s signal to an audible volume. It also ensures a more dynamically consistent sound by adding compression.
Another valuable effect of treating a direct audio signal with a preamp is that you end up with a more audible signal.
What Is A Power Amp, And What Does It Do?
A power amp is an amplifier section that can actually “amplify” sound. It comes after the preamp and after an amp’s effects loop (if it has one).
So, when it comes to your overall signal chain, the power amp is one of the last stages to affect and influence your instrument’s sound. And just like with preamps, most instrument amplifiers (e.g., guitar amps) have a built-in power amp stage. This ensures they are all-inclusive and can work smoothly with a speaker cabinet.
Preamp vs. Amp: Which Are the Best Brands To Use?
Here’s a quick overview of our top preamp and power amp picks (hardware and software) to get you started! Before you go and buy an actual piece of hardware/gear, we highly recommend trying out the free preamp and power amp VST plugins listed below.
Preamps: Hardware
There’s no easy way around it – hardware preamps are VERY expensive! If you’re after a quality piece of preamp hardware, though, it’s got to be the Audio by Van Alstine FET Valve CFR Preamplifier. For an ever-so-slightly tall starting price of $2,099, it’s a piece of equipment that can cover all audio signal control bases.
Preamps: Software
If you want a preamp in the form of a VST / plugin, that’s a lot more affordable. In fact, wait a second – here’s a link to the incredible FREE preamp VST: BritChannel by Analog Obsession! You can download it, install the files, and get cracking directly from your DAW (digital audio workstation).
Power Amps: Hardware
Most power amps are more affordable than preamps. With this said, we recommend the Fischer Amps Shaker Amp 400. For £555, you get a meaty output signal, flexible low and high-end EQ customization, and excellent compatibility with an amp cabinet.
Power Amps: Software
Because of its amp simulation and modification versatility, we recommend Native Instruments Guitar Rig 6 Pro. It allows you to combine components or choose presets of hundreds of different amp simulations based on real-life amp models that have become music industry linchpins.
FAQs
Do I Need Both A Preamp and An Amp?
If you are plugging an instrument or microphone straight into a recording interface – known as D.I. (direct injection) – you should have a preamp boosting the audio signal before anything else.
Suppose your audio signal is already prepared as an instrument sample, for example, a synth sound from a library in
What Is Preamp Distortion?
Most modern guitar amps produce some of their distortions from the preamp sections. The distortion they offer generally sounds saturated and fizzy, and they are made sensitive to high volumes.
Preamp distortion is used for stylistic purposes of creating an ‘over-cooked’ sound. It can be applied to rock guitar solos, metal/punk bass tones, and even vocals (read on – we discuss this in the FAQ section)!
Bonus Tip: K-Metering
If you have applied excessive gain to your preamp on purpose, you’re after a kind of punky, fizzy guitar tone – or maybe even a deep-fried distortion on your bass, drums, or vocals. Anything is possible in music, and over-feeding gain into your preamp does give hugely interesting results!
However, after doing this, you MUST reduce the gain of the power amp by the number of decibels you added to the preamp.
It’s essential to ensure the resulting output signal doesn’t deafen anyone and that it sits alongside the rest of the mix in a balanced way. This process is referred to as K-metering.
Should I Preamp or Power Amp vocals?
You can do either! Preamping vocals are always a MUST when recording in a studio or booth. You’ll need an audible signal level. Otherwise, the vocals will be super quiet – and even if you bring the signal up after recording without a preamp, you’ll hear loads of unwanted noise.
Using a power amp on a vocal recording is a more left-field option. It can apply excessive gain and distortion to the vocals, potentially drowning out the clarity of sung words and melodic lines.
However, it can sound great in some styles of music – listen to the distortion effect on the vocals in a track like ‘White Limo’ by Foo Fighters!
Can I Use A Power Amp As A Preamp?
Sadly not. A power amp functions slightly differently from a preamp in that it brings up the gain of your audio signal but also treats unwanted background noise like the primary audio signal, which we want to boost.
This would mean a lot of unwanted background noise alongside our desired sound, sometimes to the point of unrecognizable fuzz… not ideal!
Before You Go…
So, in summary:
Preamps come before the power amp in the signal chain and are necessary for boosting the output gain of quiet sounds to an audible level. This makes the audio signal more responsive to power amp controls, such as EQ shaping.
Power amps come last in the signal chain and are necessary for powering extra gain into audio signals that are already audible. This achieves an overdriven sound that has become a staple of Rock guitar playing – and, more recently, Dubstep / EDM synth bass sounds.
Most of the time, preamp controls should be used sparingly, with just enough volume boosting to bring your audio signal to a fully audible level. If you’re after a fizzy, distorted sound, then ramp the preamp gain up more – but remember to use K-metering afterward!
Preamps and power amps are super exciting and rewarding aspects of audio behavior to master, whether you’re an instrument player or a music producer.
After reading this article, we hope you better understand preamps, power amps, and their key features/differences.
But most importantly…
Keep digging deep and making music!
Before you go, check out our guide on the key differences between an Audio Interface vs Preamp vs Mixer!
