written by
Ziga Rezar

Audio Destruction Unit Tutorial

Gear 2 min read

A few days ago, we released the Audio Destruction Unit (ADU), and since then it has successfully "destroyed" quite a few of your mixes, bass and drum tracks! In this time, we have also received quite a few questions about its nature, use cases and controls. So, we quickly cooked up a comprehensive tutorial a.s.a.p.!

See the video below:

Audio Destruction Unit Tutorial Video

If you're not the TV type of person, here's the transcript of the controls explanations to get you started:

Bypass and Dual switches

Bypass is a true-bypass type relay switch that bypasses everything, including the transformers. It's like sticking an XLR cable from the DA to AD. Clean - and no destruction :)

The Dual switch changes the interface and controls to dual-mono operation, which is useful when working in mid/side mode or processing two mono sources at the same time.

Drive and Overdrive (for minimum or maximum destruction)

The Drive and Overdrive work in tandem as fine and broad controls of the overall gain and consequent distortion. My advice would be to first set the Drive to a low setting around 3, then use the Overdrive switch to select the ballpark of distortion amount. From there on, adjust the Drive again to fine-tune the level of distortion.

Distortion Type selector

The Distortion type selector switch lets you select different tube wiring and additional filters at the main gain stage. TR stands for triode wiring that sounds a bit warmer. PT stands for pentode wiring that’s more present and aggressive, and the PK 1 through 4 stand for peak filters in the gain stage.

To be more precise, those are band-pass filters that allow you to fine-tune the distortion to only a part of the spectrum. This is very useful in parallel processing to only augment a certain aspect of the track.

Low Pass Filter (LPF)

The Low Pass Filter switch engages the low pass filter after the distortion stage. This can be useful if you find the distortion to be too aggressive of fizzy.

Output level

Next is the Output level which is an attenuator after the distortion stage. Use it to match the input level to enable equal-loudness comparisons and to control the drive of the output transformer.


The last knob is the BIAS control that decides on which portion of the tube’s transfer curve the signal will get amplified and distorted. Changing the BIAS from fully CCW to fully CW will gradually morph from asymmetric negative part of waveform clipping through symmetric saturation to asymmetric positive part of waveform soft-clipping.

6as6 tube transfer / destruction characteristics
6AS6 Tube Transfer characteristics - setting the BIAS to center selects the even part of the line

In a less nerdy language, it has a strong effect on the distortion character. The high and low extremes usually sound a bit harsher - as you can see on the graph they are not really straight lines anymore, but curve up or down significantly. This starts to eat away at either the low end or high frequencies, whereas the settings around noon has the most neutral distortion character - but also with fewer harmonics and clipping.

Get the ADU sounds on your tracks by visiting mix:analog.

Tell me more about mix:analog and the ADU

tutorial audio destruction unit adu