Hailing from 1978, and peppered throughout several classic recordings in the ‘80s and ‘90s, the AMS DMX 15-80 S was the world’s first microprocessor-controlled, 15-bit digital delay and pitch shifter; a rack-mounted combo wonder box with a sinusoidal VCO for modulation effects. The UAD plug-in emulation has all the original goodies, plus modern upgrades such as panning, tempo sync, dry/wet mix, and a secondary VCO mode that provides a 90-degree phase offset between A and B channels for more stereo width joy (division).
One excellent added detail is the inclusion of the chorus module, an auxiliary expansion controller unit, which was mostly “unobtainium” back in the days when the hardware was in production. The chorus is a vibrant addition to most patches, introducing continuously changing pitch modulations between the two channels. The chorus pitch modulations can help build a much wider stereo soundstage for mix sources like panned background vocals or guitars, even in subtle applications. It took me a quick read of the manual to understand that feature as applied to the signal flow; true to the original rack-mount hardware, the pitch controls are locked out when the chorus is switched on because the chorus feature is manipulating the pitch values (duh!).
Speaking of the PDF manual – it’s superb, and includes excerpts from the original hardware user manual, including a pitch table with the precise values (“pitch ratios”) for setting twelve-tone musical intervals. I’d also recommend UA’s more creatively focused five-minute tips videos for the DMX 15-80 S, covering the basics and breaking down each feature section. Both resources are essential to anyone who hasn’t had their hands on the original hardware, as the depth of features coupled with the unique interface can be daunting at first glance.
One gem I pulled from the manual was that inputs A and B have a greater gain range than the original hardware. In my experiments, the input stage can be overdriven nicely into nonlinear distortion yet has a wide sweet spot for more conservative gain staging.
This unit is a stellar digital delay, but unlocking the pitch shifting modulation is key to its magic. For example, prompted by one of the notes from the original manual, I found these mesmerizingly insane arpeggiated pitch rise/drop effects (almost like the “Shepard tone” effect), which were generated by feeding in melodic source signals and setting up delays longer than 200-300 ms. The recipe? Add enough “regen” (i.e., feedback) until the unit is just shy of self-oscillating instability. Then, use the pitch ratio table (as mentioned above) to find a musical interval. Or use a pro tip: the arrow keys on your keyboard will cycle through pitch-shifted intervals after selecting one of the pitch knobs. Suddenly, we’re inside Hans Zimmer’s psychedelic Dunkirk flashback. Fun, wholly unique stuff!
A few minor fusses: The AU/VST UAD plug-in window is not sizable on a Mac, which is a shame, as the lovely interface definitely benefits from a little extra real estate on the screen. Lastly (and selfishly), we’d love to see a UA Spark native version of this released in the future to help free up some precious UAD processing. Although it’s still early days for UA’s new native refactors, the native Spark Lexicon 224 is brilliant, and I can’t wait to see what is ported over from UAD next.
With the current prices for vintage DMX 15-80 S hardware units regularly topping $8,000, it’s not hard to see why this UAD plug-in wouldn’t be the better option for most producers and engineers looking for unique sound design opportunities, or to recreate the celebrated tones of the ‘80s. C’mon – the 2022 mixing landscape needs more of that Phil Collins vocal spread. Bring it.