Distortion

Warmth, mojo and glue all mean distortion#

Tape compression, transformer saturation, drive, overdrive, fuzz, analogue warmth, tube colouration, mojo, vintage, glue. When people use those words, do you know what they mean in electrical engineering terms? They mean distortion. That's it. Sometimes with a change in frequency response thrown in.

Distortion is the marketing hype engine of the audio industry, responsible for more mysticism than any other kind of processing. Part of that is the terminology, kept vague so you think you need twenty different plugins instead of one that does the classic types of distortion. The types do genuinely differ, but the precise way to describe them is the transfer function: tanh, arctan, sine wavefolding and so on. Not adjectives. "character" is just deviation from the input, which is why a box can't be both full of character and pristine (see analogue).

Distortion is non-linear and static#

You can sort the basic audio effects into a quadrant. Gain and EQ are linear and static (EQ has a time-domain side, but it still counts as static). Reverb and delay are linear and time-based. Compression is non-linear and time-based. Distortion is non-linear and static: it typically has no time component.

Which means that if you take the time away from a compressor, by turning attack and release right down, you start to hear distortion. In the most extreme case it becomes a clipper. More on that under compression.

Odd and even harmonics are physics, not magic#

If you treat both halves of the waveform the same, symmetrical clipping or saturation, you get odd harmonics. If you treat the halves differently, for example with DC bias, you introduce even harmonics.

That blend is the whole secret of the "warm, creamy, musical" class A sound. The DC bias half-saturates the transformer at idle, so one half of the wave runs out of headroom before the other. How the Neve 1073 does it is under preamps.

There is nothing wrong with odd harmonics. Some people call it cold. I like the tone. My complaint is with hard clipping, not with odd harmonics.

Compressors distort too#

Many vintage tube and FET compressors do two jobs at once: gain across time, which is compression, and gain across gain, which is waveshaping. The grit of an 1176 comes from its JFET gain element. The harder it compresses, the more it pinches the channel and the more it saturates. Its input and output stages are clean.

With short enough time constants any compressor becomes a distortion unit. I demonstrate this in a video by making an entire beat out of nothing but sine waves and compressors.

Distortion sounds good when you are in control#

Does distortion always sound bad in a mix? No, it can sound great. In the classic studio the tape machine was the saturation centrepiece, people sent line signals through exotic mic pres to get a dirtier tone, and there were the guitar amps and stompboxes in the live room.

But you don't need to spend thousands to get it, and you shouldn't accept it as unspecified mystery colour baked into something else. Tractatus is my take on the studio's distortion side: tape, amp, waveshaping and stompbox-style modules that you can chain together yourself.