Orban 672A/674A "Paracrossalizer"
Eight bands of parametric EQ and a tunable electronic crossover in one box. Orban's own ads called it the "unequalled equalizer."
Overview
Orban built the 672A and 674A around an unusual idea. Take eight bands of fully parametric EQ, each with adjustable center frequency and bandwidth, and add 12dB/octave highpass and lowpass filters that can be tuned to work as a complete electronic crossover. The mono 672A and stereo 674A share that architecture. Orban's advertising leaned hard on the crossover-plus-EQ concept and billed the pair as the "Paracrossalizer."
The pitch was that in many reinforcement systems, the 672A/674A could be all you needed. Orban's ads claimed it replaced both a separate crossover and a conventional third-octave EQ with a single box that had better phase and time-response characteristics. It measured better on acoustic instrumentation and, more importantly, sounded better. Not every engineer bought the whole argument. Eight parametric bands with tunable filters in one rack unit was still hard to categorize and hard to replace.
In the studio, Orban positioned the 672A/674A as a single cost-effective package of EQ power that could solve virtually any frequency-contouring problem in recording, music synthesis, or broadcast production. The "Blue Chips" advertisements, a campaign that ran for years in the trade press, described it as a versatile production tool and, increasingly, as the smart choice for room and system tuning. The argument was that it eliminated the ringing and phase-shift problems that plague conventional graphic equalizers.
That claim about ringing and phase shift is the technical core of the design. A third-octave graphic EQ introduces phase anomalies because of the sheer number of overlapping filter sections. A parametric design with adjustable bandwidth lets an engineer narrow in on a problem frequency without carving up the whole spectrum. Add the tunable highpass and lowpass filters and the box can shape a room, clean up a problematic source, or split a signal into bands for a biamped system, all without patching in a second piece of gear.
The trade press took notice. Modern Recording & Music (October 1981) described the 674A as "the most powerful equalizing tool for pro audio work" the reviewer had yet come across. That quote ended up in Orban's own advertising.
Orban's marketing for the 672A/674A emphasized heavy-duty professional construction and equally professional documentation and service. Collectors generally report that the build quality holds up. These are rack units meant for installs and road work, not fragile studio-only pieces. The company sold its pro audio line through a worldwide dealer network out of its San Francisco address at 645 Bryant Street.
The 672A/674A sat alongside a deep Orban product family: the 622B Parametric Equalizer (which the company's ads called the standard by which all others were judged), the 536A Dynamic Sibilance Controller, the 422A/424A Gated Compressor/Limiter/De-Esser, the 412A/414A Compressor/Limiters, the 245F Stereo Synthesizer, and the 111B Dual Spring Reverb. Orban also sold acrylic security covers in clear, transparent blue and opaque white that fit any 19-inch rack mount product.
For a modern buyer, the appeal of the 672A/674A is the same thing that made it interesting in 1981: it does a job that usually takes two boxes, and it does it with parametric control rather than fixed-frequency sliders. That makes it useful for room tuning, for taming problem frequencies in a mix, and for anyone running a biamped or triamped system who wants EQ and crossover in one rack space. The 12dB/octave slopes on the highpass and lowpass filters are gentle by modern crossover standards, which is either a limitation or a feature depending on what you're doing — gentle slopes preserve phase behavior and sound natural, but they don't offer the steep isolation that a modern DSP crossover provides.
The main caveats are the usual ones for vintage Orban gear. These units are old enough that capacitors and switches may need attention, and the parametric controls (center frequency, bandwidth, and level for each of eight bands) add up to a lot of knobs and pots that can go bad. Collectors report that the construction is solid, but any 40-year-old equalizer with this much control surface is a candidate for a cleaning and recap. Documentation and service information exist, which helps. Orban's professional documentation was part of the sales pitch, and it has survived in the hands of owners and technicians.
Pricing on the used market is modest relative to the unit's original professional positioning. These were never consumer gear, and they don't carry the collector premium that certain compressors and preamps do. That makes them something of a value for anyone who wants genuine parametric EQ and a tunable crossover without paying vintage-boutique prices. The catch is that the buyer needs to know how to use parametric EQ. This is not a set-and-forget graphic.
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