I'm a fan of compressors that bring something to the table other than transparency, so I've had an eye on the legendary ADR F769X-R Vocal Stressor, an early outboard "channel strip" incorporating the Compex compressor alongside an EQ, for quite some time. When Boz Digital Labs announced that they were modeling "a very highly sought-after compressor hardware unit" that looked identical to the ADR, I jumped at the chance to try it out. The Compex can deliver incredibly aggressive compression; I like to think that it's one of the kings of "punchy" and/or "raw" sounding compression, in that it wrangles whatever you throw at it into submission with great ease, and you are well aware that it's happening. For instance, it's perhaps most famously tied to John Bonham's drum sound in Led Zeppelins' "When the Levee Breaks." On the other hand, the ratio knob offers more subtle ratios of 1:1, 2:1, and 3:1 (in addition to 5:1 and 10:1), so it's capable of being inconspicuous if it needs to be. The two other main elements of the Vocal Stressor are the 4-band parametric EQ and the expander; the EQ allows you to boost and cut the same frequencies as a Pultec, while the expander is unique in its ability to operate at the same time as the compressor. Additionally, in side-chain mode, the EQ allows you to compress a drum bus without the kick pumping the gain reduction, or you can use the compressor as a colorful de-esser (formerly pre-emphasis mode on Compex compressors). At the end of the chain is a limiter that is fixed at 100:1, harking back to its intended use in broadcasting. 

The +10db plug-in bundle faithfully models the Vocal Stressor in all of its glory, and includes ten presets by multi-platinum producer David Bendeth (Underoath, Paramore, Breaking Benjamin) to help you find your footing. Some find the EQ operation to be odd relative to modern EQs, as you have to toggle whether you are cutting or boosting, and then adjust the dB pot, similar to a Manley Massive Passive, but I wouldn't let that bug you. Another thing to keep track of is gain-staging, as you have control over the input gain, the expander threshold, the compressor threshold, the output level, and a wet/dry knob — without the aid of a fancy GUI and lots of meters. But again, it's all part of the charm of this legend — not a big deal. 

In use, my main objectives were to thoroughly test the things for which the Compex is most recognized — compressing kick drums, room mics, drum buses, and for "stressing" vocals. You can probably guess that I loved it, but keep reading anyway. I'd also been looking for more tension in my mixes — a way to better create a feeling of urgency and struggle — and +10db delivered in each of these scenarios. The most straightforward way of describing its style of compression is that whatever you process sounds more intense. Sometimes with other more transparent compressors, you work hard to find a sweet spot that creates a sense of intensity, but it's really easy to do with the +10db and its soft-knee curve. And what is perhaps most powerful, even more so than in the original unit, is the ability to take something right to the edge of nastiness and then dial in some dry signal with the wet/dry knob. Another fun and rather obvious use is utilizing the compressor as a killer de-esser, and then instantiating another +10db plug-in to do your compression. You can both have your cake and de-ess it too. Grab the free demo, and see if it's right for you. 

Tape Op is a bi-monthly magazine devoted to the art of record making.

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