3 – Fairchild 670
The stereo Fairchild 670 tops at least three lists: it’s undoubtedly the most expensive compressor in the world; at 30 kilograms it’s certainly the heaviest, and it is – most importantly – the undisputed king of variable-mu valve limiting.
The term vari-mu here refers to the way in which the compression ratio changes dynamically in response to the signal level. The result is a unique form of soft-knee compression which responds differently depending on the type of signal which is fed into it. The 20-valve behemoth delivers nectared attitude across a range of applications, but its most famous trick is to bestow a silky, creamy, liquid gold to the mix. This is the definitive mastering limiter.
The obvious downside of owning one of these rare dream machines is the scarcity of valves (and matched pairs thereof) and the often hefty ongoing maintenance costs. Oh, and there’s the small matter of its second-hand value; we’ve seen Fairchilds advertised in recent years for £30,000 or more.
We’ll freely admit that only the most wealthy producers could ever dream of owning a Fairchild, but we never said that this was meant to be a list of the most affordable compressors. Luckily, for those on a more realistic budget, there are several plugin versions that offer their own take on the legend, including those from Universal Audio, Waves and IK Multimedia. Some might argue that none of the software emulations sound exactly the same as the real thing, but with such a price differential that’s probably fair enough. For most of us, they’re as close as we’ll get to the vari-mu royalty.