written by
Bojan Šernek

How to achieve Analog Bloom

Gear 1 min read

Let’s face it, this is a common task: a less than exciting sound source needs to be brought to the front of the mix. The overall tonality seems to work and the EQ to sculpt the source in the mix can be done later. But the source itself is missing oomph, shine and presence - an effect known as Analog Bloom. How can mix:analog - analog over the internet service - help in this situation?

First, there is tape. It can be a really interesting addition to your process. It helps glue things together and when driven hard, will compress and saturate, bringing the source more to the front. As good as it is, tape is a “take no prisoners” effect. It either works on the source or not, there is nothing to tweak.

The second, more controlled approach is the Analog Bloom 670 chain. Producers are saying this is the most enjoyable way to control dynamics and saturation at the same time. And as always for mix:analog, executed with real analog gear over the internet.

the Analog Bloom chain - Fairchild 670 compressor and ADU Tube Simulator
the Analog Bloom chain - Fairchild 670 compressor and ADU Tube Saturato

The Analog Bloom chain

This digital unhappiness can be easily cured with the Analog Bloom bundle of exquisite tube processing. The Fairchild 670 will take care of dynamics with the ADU Saturator can add warmth, excitement and even outright distortion. This combo is a great shaping tool to add grit and authority to a signal.

The chain includes the Distopik Fairchild 670, an all-tube vari-mu compression monster. Unless you've been living under a rock, far away from human civilisation, and you've at least dabbled a bit in pro audio at some point in time, you must have heard about the famous Fairchild 670 Compressor/Limiter. It's by far no coincidence that this unit became so well known - the sound of it is simply in a league of its own.

The screaming yellow part of the chain is the ADU Tube Saturator. The ADU features no less than 6 saturation modes plus three sensitivity (overdrive) settings. It is executed as an all-tube design with and Carnhill transformer balanced inputs and outputs.

The range of tones on this box is absolutely incredible! We have paired it up with our all-analog mid/side matrix and wet/dry blend sidecar unit. With this combination, you can easily do parallel and mid/side distortion. It’s rarely seen feature on saturation units (or plugins) and we guarantee will yield very interesting and unique sounds!

Factory Presets

Starting out with the Analog Bloom is made easy with the inclusion of 25 factory presets created by Michael Moström, a mixer and recording engineer form Sweden.

The presets cover a lot of ground, from vocals to drums, bass and rhythm machines and more general “mid push” presets. To load the presets, create your session as normally and use the recall button to load them into the session.

Fairchild 670 Controls for Analog Bloom chain

Fairchild 670. Source: Vintage King


To be technically correct the fairchild has a passive attenuator placed before the main amplification stage called the Input Gain. This gain stage executes all the compression and with no gain reduction and INPUT GAIN control fully clockwise, it will add around 12dB to your level. To operate the unit at around unity gain at 3-4dB of compression, set the INPUT GAIN to somewhere between "10" and "8".

Important note: The attenuator hits the signal at the very input and always affects left and right channels even with LAT/VERT mode on. This is because the MS encoding happens after the INPUT GAIN control.


Threshold does what it says on the tin - it sets the level above which the compression will kick in. Higher number means higher threshold level, so to achieve more compression in the Analog Bloom chain, adjust this parameter counter-clockwise.

Note that to get the same levels of gain reduction, you will most likely have to adjust this parameter when changing the RATIO control.


This control was not present on the front panel of the original unit. We could not think of a good reason for that, so we automated this "set and forget" feature as well. The cool thing about the ratio control on the Fairchild is also the fact that the knee of the compression characteristic gets progressively softer with lower ratios. Just what you'd wish for on a good stereo bus compressor!

The numbers on the dial fit pretty well with the actual ratio of the unit - from close to 1:1 at fully counter-clockwise to 20:1 limiting at fully clockwise position.


Time constant selects preset combinations of attack and release times for the compressor in the Analog Bloom chain.

Generally, the bigger the number - the longer the release time. But as you can see, especially settings 5 an 6 are very program-dependant and could in today's popular terms be named "Auto Release" settings, a simple setting to start the Analog Bloom with.

Attack times seem very fast on paper, but at least to my ears, they don't sound nearly as fast as the same written settings on a VCA compressor for example. Experiment and see what combination fits your track best! Most of the time, I find this box to be surprisingly versatile for the seemingly limited choice of time constants!

AGC Switch

This is in all effect a Left-Right/Mid-Side matrix switch.

To those unfamiliar with Mod/Side principle of processing, a quick explanation: This process takes the left and right channel and makes a sum and a difference of both. So the content that is "in phase" on both channels ends up in the Mid channel and what is "out of phase" ends up in Side channel.

Mid channel thus usually contains everything panned to the centre - e.g. kick, bass, snare and vocals. What's left of the content - hard-panned instruments, reverbs and various spatial effects then appear on the side channel. This makes the MS processing mode especially useful for stereo image width manipulation.

LINK Switches

The LINK S. CHAIN switch either links or separates the compression control voltage (the side-chain signal) of the first and the second channel. Unless you're 106% sure that you know what and why you're doing, I would suggest the "linked" mode in stereo operation (toggle UP) and "un-linked" mode (toggle DOWN) in LAT/VERT operation.

LINK CONTROLS is something that every non automated hardware owner would wish to have. This is a software link on the GUI that lets you control both hardware channels simultaneously. As with the side-chain link, you will probably have it linked for stereo operation and un-linked for LAT/VERT operation.

ADU Tube Saturator Controls for Analog Bloom chain

ADU Tube Saturator controls
ADU Tube Saturator controls

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. The other part of the Analog Bloom (the fairchild) can still be used normally.

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 distortion)

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 Analog Bloom.

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 of the Analog Bloom chain. 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.

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.

Tell me more about mix:analog and the Fairchild 670 / ADU Tube Saturator

fairchild adu tubes saturation