Gain, Drive and Distortion

Gain, Drive and Distortion

We realise that this topic is extremely contentious because the definitions of ‘Gain’, ‘Drive’ and ‘Distortion’ all overlap considerably, so much so that even the professionals struggle to define them exactly without reams of technical explanations. Having received a number of questions on the subject, we thought we would try to explain the differences in layman’s terms.  So, with the apologies out of the way, here goes…

First of all, we should explain that gain, drive and distortion are all basically just slightly different forms of distortion. The different terms merely try to explain how the distortion effect is generated and therefore give the guitarist a feel for what sort of distorted sound will be produced.

Dave Davies, the guitarist with the Kinks is often credited with first using distortion when he slit the cone of the speaker in his Elpico amplifier and discovered that it created an amazing buzzy sound. He was so impressed with this unusual ‘distorted’ sound that he used it on the Kinks’ next record ‘You Really Got Me’ that was an instant hit and reached number 1 in the UK charts in September 1964.

In reality, slightly distorted guitar sounds had been around for a while but his sound was far more strident and extreme. Most guitarists at that time were searching for the sweetest and most natural guitar sound by keeping distortion levels down to an absolute minimum.

Once Dave Davies had a hit with the distorted guitar sound, many other guitarists wanted to emulate the sound and they started to explore their amplifier and guitar to try to replicate the exciting distorted sounds. They soon found that by turning their valve amplifiers up very loud and turning up their guitar’s volume controls they could get the amplifier to start to distort their sound in a warm fuzzy way. This was because the valves were being driven to extreme and when this happens, the valves tend to compress the peaks of sound giving a warmer distorted sound with added harmonic tones.

Gain

This effect was initially called ‘distortion’ but increasingly, it was became known as ‘gain’ because the effect was created by turning up the gain control to overload the input stage of the amplifier.

Guitarists also noticed that the more powerful pickups (like humbuckers) induce the distortion effect far more readily because they generated a stronger signal than say, single coil pickups. As a consequence, around this time, guitars with more powerful pickups became popular with guitarists who were looking to incorporate the distortion effect into their playing.

The only problem with ‘gain’ distortion was that the only way to introduce it was to turn up the amplifier and guitar close to full volume. This was a little impractical for the guitarist and potentially uncomfortable for the audience. As a result, some innovative amplifier manufacturers started to construct amplifiers with a second ‘gain’ channel, controlled by a footswitch, that had a ‘gain’ control (pre-amplifier volume control) and a ‘master’ (output stage) volume control. By switching between the two channels the guitarist could introduce a distorted ‘gain’ effect at any preset volume level, at any point in their playing.

Drive (or ‘Over-Drive’)

It wasn’t long before some enterprising manufacturers started to make foot pedals that amplified the signal from the guitar so that the ‘gain’ effect was more controllable. This meant that even guitarists with lower output pickups could generate enough signal to ‘drive’ (or ‘over-drive’) the input stage of their amplifier to bring on the warmer distorted tones.

The designs of these ‘drive’ or ‘over-drive’ pedals often included controls to vary the level of signal gain to suit the guitar pickups, amplifier specification and desired volume and distortion levels. They also included a footswitch to make it quick and easy to introduce the distorted tone at the press of a footswitch.

Distortion

Around the same time, some engineers tried to tackle the challenge of introducing distortion by approaching the problem in a different way. Their thinking was to design a pedal that would distort the signal using the small and relatively inexpensive ‘transistors’ that had recently become available from Japan. These ‘distortion pedals’ introduced a controllable level of distortion into the signal path between the guitar and amplifier. This meant the distortion would occur at all volumes levels and would not need the input stage of the amplifier to be ‘over-driven’. The distortion level could then be varied at the pedal and could be introduced into the music, at any volume, at the press of a footswitch.

Unlike valves, transistors do not compress the signal when they get overloaded, nor do they add the warmer ‘over-tones’ that valves do, so although the concept worked well, these ‘distortion pedals’ tended to have harsher, brighter tones than the over-driven input stage of a valve amplifier. This harsher distortion tone soon earned them the nickname of ‘fuzz-boxes’.

Many guitarists liked the brighter distorted tones of these new distortion pedals and many models became extremely popular with guitarist at all levels across all genres of music. Many are still popular and extremely collectable today.

Conclusion

The terms ‘gain’, ‘drive’ and ‘distortion’ are often used to mean the generic term ‘distortion’ but in reality, they each have slightly different tones and effects. If you are looking to introduce a distorted sound into your tone palette then it makes sense to go and try out a few amplifiers and pedals in a friendly music store and seek the advice of the sales staff.

If you are trying to emulate the specific tone of one of your favourite guitarists then some research on the internet might help point you in the direction of the effects they use. Many professional guitarists and their guitar technicians have produced ‘gear guide’ videos that explain their gear setup and these should give you a good idea how your favourite guitarist obtains their signature distortion sounds. Don’t be surprised if you find that many leading guitarists feature all three forms of distortion in their gear set up.