Saturation is one of those topics I can talk about all day. Regarding preamps, we’ve touched on this subject briefly talking in detail about THD, Tubes and Transformers.
Today, I want to take a deeper look at the possibilities of utilizing saturation in the mix and how it can help your tracks to stand out amongst others that feel less exciting or fall flat.
Let's dive in.
Tape
Tape saturation is the hallmark of studios. It’s what everything was recorded to back in the day before the digital age took over and it still a staple in most professional studios in one way or another. Rather than recording to tape now, however, people are using it as an insert on one track or on a bus track to ‘color’ the sound of one or many instruments.
Magnetic tape is well known for the angelic top end and solid lo resonances and harmonics that occur when the tape head is pushed. The more the signal is driven, the more distorted and destroyed the sound becomes - especially helpful when trying to bring to life a drum kit when the room isn’t doing enough to bring the energy needed for the vibe you’re going for.
On guitars, it's a wonder trick to glue together pokey transients as it’s similar to clipping (check out the 5 Mastering Tips for more on clipping here) and solidify the lower midrange for thin or hispy sounded rhythm guitars. Tape has been long used on guitars for decades in various ways, but if you’re looking for another means, try Tape Echo on your lead guitars and drive the tape heads if you have the available parameters as this will give a similar effect but only on the delayed echos.
Tube
Tube saturation is the longest standing well known use of saturation, straight from the first revered preamps back in the 40’s and 50’s. The Telefunken V72 preamp is one of the most commonly associated names when tubes are thought about, but other than preamps there are some seriously amazing achievements from other types of gear that are worth taking a look at here.
The Vari Mu compressor for example is a great tool to bring your vocals, or drums to life. These master-build compressors are hard to come by and cost exorbitant amounts because of not only their makeup, but the sheer sound quality of its design. Pushed, they can annihilate a drum track and add tube flavor like no other means I’ve found in my career so far - I personally love crushing a source, then pulling back on the mix knob to dial in the perfect amount of glue and saturation.
On Vocals, I like to use the subtle tube harmonics and warmth only pushing it slightly, to bring out the chime of the top end on a vocal bus - as the attack is fixed, play with the release settings to find the right feel for you. Usually between 1 (fastest) and 3 (medium) I find it's easy to find a middle ground between how fast the track is moving and if the vocals need taming (think leveling amplifier), or shaping (think VCA Compressor) to fit into the track.
Transistor
Transistors are most well known within FET compression - the 1176 being the most noticeable mention here - for their heavy, hamonic, unstable distortion that can be very sought after for drums and vocals mainly.
In order to not use the compression side of FET designed units we’re left to search for more obscure an less known models such as the Vertigo Sound VSM-2 which has a FET circuit aimed at bring up the 2nd order harmonics of the audio processed in a ‘valve type’ sense, aimed at being used in parallel to blend the level of distortion added. Similar to how you would use a mix dial on parallel compression, this unit does a similar task as if you were to obliterate a signal through say an 1176, and dial back the mix - but without the compression taking place and only the saturation artifacts. The only digital recreation of this unit is from Plugin Alliance currently, but a similar feel/vibe can be accomplished through a number of digital plugins (although all slightly different), they all achieve a similar transistor, crushed, crunchy feel such as The Monster Virtual Mix Rack unit from Slate Digital, the Omega A and N transformer saturation plugins from Kush Audio, and Softube Harmonics Unit.
Remember to use saturation sparingly across the board - heavy hands can ruin a track very quickly if too much is added creating much less cohesion and decernability between instruments causing them to blend too much (similar to how too much reverb can take over). If you use these techniques, try an A/B test between and remember: it's like in cooking - too much spice can ruin a dish!