Tube compression

Tube, or variable-mu, compressors also have a slow attack,¹ controlled by a vacuum tube. The ratio of gain reduction increases as the level increases (reminds me of Pro-C 2’s vocal mode). These were the first compressor design, created in the ’50s.² The Fairchild 670 is the most famous example.³ The Fairchild is made up of 20 valves and 14 transformers.⁴

Tube compression works kind of like sandpaper, for smoothing things out.⁵ They are particularly well-suited for gluing buses and mixes or for giving an extra push when dynamics are already nearly-perfect.⁶ They also work nicely for Compressing bass.⁴

I like MJUC best for tube compression. MTurboComp also does a Fairchild as well as a Manley Vari-Mu. Reaper’s Fairly Childish Compressor is based on a Fairchild.

Rick Beato likes Fairchild 660 on bass or piano. He also uses it on vocals.⁷ Geoff Emerick, Steve Churchyard, and Tom Elmhirst like to run vocals through it more for the sound than the compression. Steve Churchyard, Tom Elmhirst, Manny Marroquin, and Elliott Scheiner like to use the Fairchild on drums too, following after Emerick who recorded Ringo with a Fairchild.⁴