Gain Stacking
The what, why and how of combining drive pedals to unlock a world of potential
What is gain stacking?
This is when you use multiple pedals that add gain to your signal. These can include compressors, preamps, boosts, overdrives, distortions, and fuzzes - not to mention your amp itself! You might have heard studio engineers or producers talk about ‘gain staging’ being important for recording; gain stacking is essentially the same process for guitar - crafting a tone by carefully increasing the gain, compression and clipping applied to a signal. The most simple version of this, of course, is to put a powerful boost or preamp in front of a tube amp, crank up the pedal and listen to the amp break up into overdrive. In most cases, you’ll already be gain stacking without realising it, as elements of your chain will have preamps, or blend controls, which are often built using an amplification stage. Legendary tape reverbs like the Echoplex EP-3 and Roland Space Echo included a preamp, which acted as a boost - hence why Nick Zinner from Yeah Yeah Yeahs has a tapeless Space Echo in his setup. Many pedals also incidentally have preamps, like the excellent one in the EHX Deluxe Memory Man, or the Catalinbread Topanga Spring Reverb.
Why should I consider it?
There are a number of compelling reasons. Firstly, you can often get very musical overdrive at lower volumes. Second, you can get much higher levels of distortion from your gain pedals or amps. One of the classic modern metal tones is a Peavey 5150 with a Tube Screamer in front - adjust the tone control to taste, turn the level to full and the drive right down. Slamming any decent tube amp like this is likely to greatly change the character of the amp’s distortion. Third, the timbre of the compression can be very distinctive, leading to guitar tones that just aren’t possible in other ways. Fourth, small changes in the combination of pedals can sound wildly different - great if you’re in a covers band and need to cover Hendrix and Zeppelin in the same night. Finally, different drives have different EQ profiles - for example, using a treble boost at either the start or end of your stack will brighten up otherwise muddy drives and add some top-end sparkle to your sound.
Are there downsides?
Most obviously, you need to own multiple pedals, although these days even budget micro-pedals are of a high quality. You need to spend some time with your gear working out the order, and listening to what works in different situations. If you switch amps, you might find that pedals react differently. Finally, if you have several gain pedals on your board, you might discover that you don’t have space for much else!