Words and photos by Rafe Arnott unless otherwise attributed. Image above: The Varia Instruments RDM-20 rotary mixer.
In a hobby where gear fetishism seems the rule, not the exception, it should come as no surprise that signal-path purists and audiophiles of a dance-floor bent have come to worship the analogue rotary mixer. It is lensed as an essential piece of kit because it harkens from days when the only thing that mattered was having the latest records and the biggest sound. To be clear, I’m not talking about Kool Herc disciples (of scratching or breaks), rather, I’m referring to the long playing disc jockey, or perhaps more accurately, the selector who takes their cues from dance party pioneers David Mancuso, or Larry Levan.
Selector is a title handed down from Jamaican sound systems of yore: DJs, recording engineers and MCs who first championed massive speakers and powerful amplifiers as they battled for supremacy in the cutthroat dub and rocksteady scene of ‘60s Kingston. The sonic legacy of giants like Osbourne Rudduck, Edward Lee and Rudolph Redwood endures for a reason. And, as with all things of a moment, renewed interest in the rotary mixer (which started around the mid-‘00s) came from referencing dance culture’s roots, rather than what was de jour. Many were looking for that huge sound from dub and disco’s heyday, but there was a recipe to be followed which had been lost along the way with MP3s, digital mixers, CDJs, and the cheap watts which comprised most club PAs starting in the early ‘90s.
Photo left: Modern classic. The MasterSound Radius 2 rotary mixer with Technics 1200 MK7.
For the uninitiated, a rotary mixer is a piece of equipment that allows for the seamless transition between two audio sources – be they digital or analogue – via rotary dials instead of the sliders most associate with mixers (other dials are also present, which can be used to attenuate frequency ranges – treble, midrange, bass – as well as output, tape level, booth mix, etc.). Like horizontal slider mixers, all have an headphone output, most are equipped with at least two line and two phono stage inputs, and depending on your budget can range from approximately $1,000 USD to $10,000 USD. Some are equipped with discrete components – featuring no integrated circuitry in the signal path – are built by hand, are often bespoke, and produced in small quantities. As one’s budget for a mixer shrinks, so does the ability for manufacturers to not use ICs. Regardless, in the sense of build/sound quality every rotary mixer company I’ve spoken with (not surprisingly) is focused on providing the best sound at a respective price. And that’s really the point here, sound quality with a rotary mixer is paramount, not secondary to convenience or budget.
"The idea of sound quality not being first and foremost is heretical for audiophiles."
–Rafe Arnott
The idea of sound quality not being first and foremost is heretical for audiophiles. But in the traditional disc jockey component biosphere, while the mixer is arguably one of the key components for SQ, it, like much of the analogue playback chain, became overlooked in the middle period (’90s and ’00s) of dance floor history because of the rise of digital music formats, and preceding this, the advent of cheaper, lower quality, horizontal crossfaders like the GLI PMX 7000. Released in 1977, the 7000 is a monument itself to the art of the quick transition between LPs in the style of one hand, a technique that was instrumental in enabling cutting and scratching, a phenomenon that transformed hip hop and rap and relegated rotary mixers to the realm of music history geeks and audiophiles.
Photo above: A vintage Bozak CMA-10-DL2 analogue rotary mixer.
But it was the embrace of CDs instead of LPs that was to herald the biggest slide away from the analogue chain to digital. Denon was first to the floor in 1993, and then Pioneer with the CDJ-1000 in 2004. In this history the rotary mixer (and its focus on the highest quality components for the best sound), premium amplification and loudspeakers, all became less important as the medium of the source – digital – and its sound quality, all took a backseat to convenience. Convenience does funny things when it comes to prioritization of quality. Times change, and it became more important for a DJ have 10,000 digital albums on a hard drive to access (of dubious recording provenance) than it was to have 100 curated LPs for playing.
Photos above: Left – Jamaican dub soundsystem circa early '70s. Image courtesy Museum of Youth Culture. Right – Larry Levan behind the decks and at the helm of a Bozak CMA-10-DL2 mixer. Image courtesy Bill Bernstein/serenamorton.com.
The hardcore, homegrown vinyl-only scenes which influenced dance music culture around the world in the ‘70s had organically blossomed around private parties where the atmosphere – and importantly an audiophile-grade sound system – was paramount. (Read this two-part article and familiarize yourself with some key players who shaped global DJ culture HERE. It was about creating an entirely analogue, holistic dance/music/social experience which legends from the time like Mancuso were attempting (and succeeding) at curating with equipment like McIntosh valve amplifiers, Thorens belt-drive turntables, Koetsu moving-coil cartridges, and Klipschorn or Altec Voice of The Theatre loudspeakers.
One of the first rotary mixers to make it into the hands of influencers in the ‘70s was the Bozak CMA-10-DL2 (and its highly regarded, but cheaper clone, the UREI 1620, which hit club booths in 1983). The Bozak, designed and built like a tank made inroads quickly in the burgeoning United States disco scene and was inspired itself by U.S. electrical engineer Alex Rosner’s early mixer prototypes. (Amazing side note: Rosner’s family worked for Oskar Schindler during WWII, and were saved from Auschwitz because of it) Rosner started building sound systems back in the late ‘50s, but it was his “Rosie” DJ mixer that debuted in 1971 that helped kick off a revolution in dance music culture by fundamentally altering the way jockeys played records. Despite being a tool designed for club DJs, the CMA-10-DL2 was a descendent of the radio booth, modelled from existing mixing boards. This is where the inclusion of large knobs, instead of sliders, to regulate output of each channel came from: broadcasters knew that knobs have a higher SQ, and are more durable than sliders. This professional background reinforced the perception that knobs were better, and led to successive generations of disco/house DJs fetishizing over the two-handed style of mixing which the rotary engenders.
In what could be a classic chicken-and-egg scenario, there are claims Rosner built prototypes of the Rosie from Bozak parts, as it was originally conceived for broadcast use. Rosner based the design on a modified mono mixer that he received permission to adapt to his own plans after he reached out to Louis Bozak. Utilizing two headphone amplifiers for the cueing system and a sliding fader/mixer, the Rosie was born and found its way into the hands of Francis Grasso at the legendary Haven Club in NYC, a man referred to as the “Godfather of DJing.” This is part of the rotary mixer's innate appeal (other than its performance). Nostalgia being a powerful confluence of emotions, and many a thousand ships have been launched in an effort to recreate a moment in time.
Hardware nostalgia enablers, like the CMA-10-DL2 have cachet, as they are imbued with as much emotional and cultural qualifications as practical ones. The Bozak was designed to serve a purpose, albeit with a very high degree of build and sound quality. It appeared at a critical juncture in the timeline of dance music – it literally helped birth modern DJ culture as a way to seamlessly transition between two LPs. These facets lend an air of authenticity which is reassuring for dance music culture’s traditionalists. As such, rotary mixers are lensed within a rosy prism of memory, or an poignant sense of legitimacy for those coming to the party late. The practical side weighs heavy too. Disc jockey’s of the time were demanding a high level of performance from equipment based on their experience with what Mancuso, Levan and other pioneers were using for their private parties or club rotations (not the least of which were Mancuso’s legendary Loft gigs).
Photo above: One of the early Alex Rosner "Rosie" mixer prototypes. Image courtesy of Stonyroads.com.
A rotary mixer was seen as essential to the signal path if you were a selector who was serious about sound, and Mancuso had influence on generations of DJs coming up after him in NYC and abroad when it came to sound system curation. His meticulous attention to detail in every part of the set-up, from the phono cartridges, tonearm cabling, interconnects, valves in the amps, the position of the loudspeakers for those Loft parties… the mixer, all contributed to his success. This was a cornerstone to the immersive – and wholly inclusive – experience he was championing. Gay, straight, bisexual, however one identified, Mancuso was creating a safe space for those who wanted to dance without judgement. It was built around love, respect, and outstanding audiophile-grade sonics.
Photo above: Bozak CMA-10-DL2 internals showing discrete component layout and wiring.
One of the companies at the forefront of the return of the rotary mixer in the mid-‘00s was Jerôme Barbé and his Paris, France based E&S, which focused on an all-analogue signal path. E&S utilized high quality resistors, capacitors and transistors, ALPS potentiometers, and hand soldering for the DJR400, which the company’s website touts as the “first portable rotary mixer.” Designs like the DJR400 inspired a whole new generation of audio engineers, electronics enthusiasts and entrepreneurs to take up the mantle set down in the ‘70s by Bozak and UREI (Bozak is now back to building their rotary mixers as well). But this movement to bring back the rotary mixer didn’t materialize out of thin air, it was the economics of a changing DJ landscape. One being shaped by the slow, steady rise of global vinyl sales and the rush a new cohort of selectors were experiencing with the hands-on techniques (and sound quality) involved with mixing LPs and 45s. This reawakening brought the (somewhat lost) art of mixing with a rotary back into vogue. Companies like Allen & Heath, Isonoe, MasterSounds and Varia Instruments (to name but a few) quickly filled the void, meeting a growing demand for artisanal, bespoke rotary mixers as audiophile quality sound and physical media got back into the ring.
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