The Inimitable Manley Massive Passive Equalizer

Editor’s Update: Good News! The Manley Massive Passive EQ is now available for purchase as a UAD-2 Powered Plug-In.

The Manley brand has been synonymous with no-compromise, outboard recording equipment since its beginnings in the late ‘80s in the old Vacuum Tube Logic of America building. In 1993, Manley Laboratories Inc. became a separate entity apart from VTL and took up residence in its own, new factory located in Chino, CA—just 35 miles east of Los Angeles. Manley Laboratories Inc. has continued to expand and thrive in recent years under the leadership of owner, EveAnna Manley, and through the success of their full-line of revered analog equipment, such as the Vari-Mu® Limiter Compressor, the VOXBOX®, and the subject of this month’s Analog Obsession, the Massive Passive EQ.

Massive Passive Mission

Making its debut in 1998 and racking up awards and accolades soon after and ever-since, the Massive Passive (nicknamed “Massivo” by some of its assemblers) was designed to meet some very specific goals. To begin with, Manley wanted to focus on features that many studios and engineers were asking for in a new EQ design: “Click-switch frequencies,” and “character” over “clinical”. Manley also strived to create a “passive” EQ that relied only on capacitors, inductors, and resistors for shaping the tone. This was in keeping with the design aspects of Pultecs and other of their favorite vintage EQs, and something that had been absent in the majority of modern EQs that had begun to use integrated circuits in place of inductors. Most importantly, Manley’s mission was to create an EQ that sounded amazing and included features that weren’t available anywhere else. The results speak for themselves with this two-channel, four-band, “passive” EQ with additional high- and low-pass filters. Utilizing design strengths from choice console, graphic, parametric and Pultec EQs, Manley has successfully delivered a fundamentally different EQ that’s beyond compare.

Massive Passive in Action

In its mere dozen years of existence, the Massive Passive has amassed a long list of adjectives to describe the sound that its parallel topology, passive tone shaping, and tube-driven boost circuitry afford. It has been often referred to as “natural”, “organic”, “smooth”, and “sweet” -sounding, to mention just a few. These characteristics have attracted many from a different list connected to the Massive Passive: Famous, professional users. Artists and engineers frequently cite the Massivo’s role in both mixing and mastering audio duties in film and music. In an interview with Sound On Sound, mastering engineer Jon Astley shared how he used a mastering version of the Massive Passive EQ when working on Tori Amos’ A Piano: The Collection. When renowned brazilian drum-n-bass artist Amon Tobin set out to mix Foley Room — an album composed from entirely “found sound” and original samples — he relied heavily on the Massivo’s “natural” sound to blend all the samples together. Engineer Jim O’Rourke had this to say to Mix, “The Massive Passive shapes things the way you want it. It's very accurate, but it's musical. It doesn't sound surgical to me.” while describing how he and guitarist/songwriter Jeff Tweedy from Wilco used the Massive Passive during the mixing process for the band’s critically acclaimed Yankee Hotel Foxtrot. Esteemed mastering engineer Bob Ludwig from Gateway Mastering is another well-documented fan of the Massive Passive EQ. The Massivo has even made its way onto the big screen at the hands of top Hollywood score mixer Alan Myerson. Myerson has collaborated on over 30 films with legendary, award-winning score composer Hans Zimmer, and offered this in an interview with Mix, “[W]hen I mix, I always have my Manley Massive Passives across the orchestra … If you listen before and after, it makes this tremendous difference. Besides the EQ itself, I think it's that little bit of the saturation that happens in the tubes.”

At First Glance

The front panel of the Massive Passive is symmetrically laid-out for its two channels and consists of 31 rotary knobs and 16 toggle switches. The odd rotary switch, found dead center, functions as the “On/Off” switch for the unit. Upon turning this switch to power-up the unit, the 16 toggle switches will immediately report back when switched between “Boost/Cut” with backlit panel labels. Showcasing their attention to detail, Manley has included a built-in “Warm-Up” circuitry that forces the unit into “Bypass” for 20 seconds to prevent harmful signals being sent to your speakers. Once this warm-up cycle ends, you are greeted by the warm, cerulean stare of the twin EQ “In” buttons located on each side of the power switch.

The rear panel of the Massive Passive features an I.E.C. power connector, a chassis-grounding terminal strip and the actual power transformer — most likely for sonic reasons. Each channel provides ¼” phone and XLR input and output jacks. The ¼” phone inputs accept balanced or unbalanced connections and are factory set-up for +4dBu pro levels with internal DIP switches that allow for -10dBv semi-pro or hi-fi levels. The ¼” phone outputs are unbalanced only but can also be changed via internal DIP switch between +4dBu and -10dBv. The XLR inputs accept balanced or unbalanced connections but only support +4dBu pro levels. The XLR outputs are Transformer Balanced and Floating and set for +4dBu pro levels. The DIP switches have no effect on the XLR input or output jacks.

It is clear that all of the components have been carefully selected. In lieu of a large cluster of transistors (as with many EQs), the Massive Passive uses only metal-film resistors, film capacitors and hand-wound “at the source” inductors for sculpting its sound. Amplification is handled in typical Manley fashion, by way of a compliment of triode tubes. Each channel features two tube amplifiers. These amplifiers are used only to make up for the up to 50 dB loss caused by the passive circuitry. Manley took the approach of creating this EQ through a mixture of “a little more art than science.” The components used were therefore chosen to interact “musically”, rather than to meet numeric ideals in terms of bandwidths or sheer dBs of boost.

The Four EQ Bands

Unlike many traditional EQs, the MP’s gain controls are “flat” in the fully CCW position as opposed to the expected 12 o’clock setting. This serves two purposes: 1) Provides twice the normal gain resolution compared with center detent pot’s and, 2) Provides a more accurate “flat” setting, as pot’s with a center detent can still be doing some EQ when set “flat”.

The “Out” or “Bypass” setting on the toggle switch is not a true hard-wired bypass, but does disengage your filter and tube-driven make-up gain stages while keeping your input amp and output transformer “in-circuit.”

The Massive Passive employs a “parallel” circuit topology instead of the more traditional “series” EQ design. Each of the Massive Passive’s four EQ bands has a +/-20dB gain range with a 3-position Cut/Boost/Out switch and a second switch for selecting between Shelf or Bell curve. An 11-position click-switch rotary knob lets you select your center frequencies, while a continuously variable Bandwidth pot allows you widen or narrow your curves. The settings overlap and interleave, with a low band range of 22Hz to 1kHz, low-mid of 82Hz to 3.9kHz, high-mid of 220Hz to 10kHz , and high of 560Hz to 27kHz. This design results in a strong amount of interaction between the bands—particularly in the Gain and Bandwidth controls. Because of these interactions, it is unlikely you will be able to gauge the exact number of dB change as it relates to the Gain control knob’s position. As another example, if you set all four bands to the 1K and apply 20 dB of boost to each, the total boost will only be 20 dB, not the anticipated 80 dB. Note that the full 20dB cut/boost range is only available in Shelf mode at a wide bandwidth. As you narrow bandwidth settings, the gain drops to +/-12 dB. Expect the opposite with Bell curve settings, as the +/-20dB max can only be achieved at the narrow settings. Ultimately, this allows for unique EQ curves unattainable with traditional EQs. As is often the case, let your ears be your guides.

Another testament to Manley’s attention to detail is the way in which the two lowest and the two highest frequencies available are voiced differently in shelf mode by the action of their bandwidth controls. This provides “airier” high frequency shelves, and “tighter” low frequency shelves at the extremes.

The Additional Low-Pass and High-Pass Filters Section

The High- and Low- Pass Filters are positioned below the Master Gain Trims. These 6-position knobs each offer a choice of 5 frequencies and an “Off” position, which are a sensible range of 22, 39, 68, 120 and 220Hz for High-Pass, and 6, 7.5, 9, 12 and 18kHz for Low-Pass. These filters were made especially steep — 36 dB per octave. An extremely steep and very useful 18kHz filter is a modified elliptical filter down 60dB (theoretical) one octave up, but really only drops about 40 dB for "warming up digital". The three lowest of the Low-Pass filters have a slight boost just below the cut-off frequency to add a little color instead of “dullness.”

Massive Passive Mastering Version

There is also a mastering version available of the Massive Passive EQ. While it does share a number of features with the standard version of the Massivo, there are a few distinctions that make this second version more practical for mastering engineers:

The parametric frequencies remain the same on both versions of the Massive Passive, but the additional five High-Pass and five Low-Pass filters have been specifically tuned and custom tailored for the mastering version by being flatter until the knee and providing lower and higher range than the standard version, with mastering engineers specifically in mind. The slopes for the mastering version are 18dB per octave.

Mastering Version High Pass Filters: 12, 16, 23, 30, 39Hz, OFF
Mastering Version Low Pass Filters: 15K, 20K, 27K, 40K, 52KHz, OFF

The Mastering Version has replaced the Master Gain Trim control pot’s of the standard with true 11-position 1/2 dB stepped Grayhill switches set up for a range between -2.5 to +2.5 dB. A stepped rotary switch for the mastering version has also replaced the continuous control Bandwidth pot of the standard version. This makes for more accurate and confident left and right matching as well as recall-ability for mastering purposes.

For more detailed information on both versions of the Massive Passive EQ, as well as all things Manley, visit their website.

— Mason Hicks