Download UnderTone Audio UnFairchild for Mac

In the edit

You drop it on a drum bus and suddenly the snare sits right, the kick has weight, and the whole kit breathes without pumping. That's the UnFairchild doing its vari-mu thing — a plugin version of the UnderTone Audio 670M mkII hardware, built with MIXLAND and Eric Valentine.

Vari-mu compression — gain reduction that responds to signal level rather than a fixed threshold, giving a smoother, more musical squash.

Feed-Back and Feed-Forward — two classic compression modes; feed-back is gentler and more vintage, feed-forward is tighter and more controlled.

Six original preset time constants plus four variable ones — quick recall for familiar settings, or dial in your own attack and release.

Wet/dry control — parallel compression without extra routing, so you can blend in the uncompressed signal.

Side chain processing — lets you trigger the compressor from another source, useful for ducking or de-essing.

DC Threshold and THD control — adjust the threshold behaviour and add harmonic colour to taste.

True bypass — when it's off, it's out of the signal path entirely.

It works on individual tracks, but it shines on buses — drums, vocals, even the mix bus. For the undertone torrent download, grab the latest version and see where it fits in your session.

Process mid and side signals independently with the MS function

The UnFairchild has a few features that don't make the headlines but save time once you know they are there. The MS function lets you process the mid and side signals independently, which is useful for tightening the centre of a drum bus or widening a vocal without affecting the rest of the stereo image. It is one of those controls you reach for more often than you expect.

The fine adjustment of left/right balance is another quiet workhorse. If your mix has a snare or a vocal leaning slightly off-centre, you can nudge it back without reaching for a separate utility plugin. It is a small thing, but it keeps your session tidy.

Output level control does what it says — you can compensate for gain reduction without adding another trim plugin. Pair it with the wet/dry control and you can dial in parallel compression and level-match in one place.

The true bypass is worth mentioning again in context. When you toggle it off, the plugin does not colour the signal at all. That makes A/B comparisons honest, especially when you are deciding between the Feed-Back and Feed-Forward modes on a vocal take.

Native support for both Intel Macs and Apple Silicon without Rosetta

So whether you are on an Intel Mac or Apple Silicon, you are covered. No Rosetta workarounds needed on newer machines.

Is it a direct copy of the hardware? It is described as a painstaking recreation of the UnderTone Audio UnFairchild 670M mkII vari-mu compressor, developed with MIXLAND and Eric Valentine. That means the circuit behaviour, the time constants and the character of the compression have been modelled from the hardware unit. It is not a generic emulation — it is the same team behind the original.

Can I use it on anything other than drums? The official product page mentions drums, drum bus processing and vocals specifically. In practice, vari-mu compression works well on bass, acoustic guitar and mix bus duties. The six preset time constants cover a range of sources, and the four variable ones let you fine-tune for material that does not fit the presets.

What about the side chain? Yes, side chain processing is included. You can key the compressor from another track — useful for de-essing a vocal with a side-chained EQ, or ducking a bass part under a kick drum. It is a standard feature here, implemented without fuss.

How do I install it? The installation and activation instructions are included in the package. It comes as a plugin, so you place it in your usual component or VST folder and authorise it from there. The process is straightforward, but the instructions cover every step.

Under-the-hood refinements in version 1.0.8 for everyday stability

Version 1.0.8 is the current release. No version-specific changelog was available in the official material, so the changes are likely under the hood — compatibility fixes or small refinements to the modelling. If you are coming from an earlier build, the features you reach for every session remain the same: the six preset time constants, the wet/dry blend, the MS function and the THD control. The plugin behaves as expected on both Intel and Apple Silicon Macs running macOS 10.13 or later.

UnderTone Audio UnFairchild emulates vintage tube compression, ideal for producers seeking rich analog character. It is stable, it covers the full feature set, and it does not introduce any workflow changes that would slow you down mid-session. The unfairchild plugin remains a reliable choice for vari-mu compression on drums, vocals and buses.

New this release

• No version-specific changes were available in the gathered official material.

Mac it needs

• macOS 10.13 or later
• Intel or Apple Silicon Mac
• Interface language: English