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Volume 2, Number 3, April 2004
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Analog Obsession: The Pultec Family

The new Pultec-Pro plug-in combines the
Pultec EQP-1A and MEQ-5
With UA’s new plug-in release of the “Pultec-Pro”, I thought it would be fitting to delve a little deeper into the history of the company and products that brought the burgeoning audio industry of the 50’s the innovative technology which is still widely used and copied. The original tube EQP-1A fetches around $4000- $5000 on the used market, and several companies have adopted the technology for modern recreations of this revered studio icon.

UA’s new Pultec-Pro Combines the two most widely used Pultec EQs; the EQP-1A Program Equalizer, and the MEQ-5 Mid Band Equalizer, which when used together, give the user a well-rounded EQ palette. This combination is still standard fare in recording studios and was once widely used in mastering sessions.

In 1951, Pultec introduced the first passive program equalizer, the EQP-1. The EQP would see many iterations, but this basic design would be the company’s flagship product until the company’s folding in the late 70’s/early 80’s. The company was neither bought nor sold; Pultec simply closed its doors.

The original EQP-1A program Equalizer
Founders Ollie Summerland and Gene Shank (no, not a family relation to me) made up the famous two-man operation of Pultec (the formal name being Pulse Techniques Inc.), who made every item to order, all by hand. The two men comprised the engineering, marketing, sales and production staff for the entire history of the company! The Pultec storefront was located in Teaneck, New Jersey (although the formal address was West Englewood, NJ), the same town where Les Paul built his first “home studio” and incorporated the first eight-track recorder.

An interesting note in the Pultec design legacy, the passive EQ circuit designs were licensed from Western Electric. Pultec combined the passive design with a tube gain make amp to overcome the typical 16 dB insertion loss of a passive equalizer. So this made the Pultec appear to be "lossless."
Original MEQ-5 Midband EQ

The build quality and design of all the Pultec products was unparalleled. A testimony to this is the numerous working units still available in the audio production world. It is said the men were very secretive about their designs, and very few were ever allowed to visit the facility. In addition to the famous tube EQ’s, Pultec also made solid-state versions of these units, which were the silver-face variety. Perhaps less known, Pultec made filters, small mixers and preamps, one of the most intriguing products being the MAVEC, an early “channel strip” that included a mic-pre, eq, and simple compression all in a 2U rack mount design.

In Use
The Pultecs are known as magical tools that improve the sound of audio simply by passing signal through them; by who wants to leave it at that? The Pultecs have long been a choice of recording and mastering engineers for their ability to bring out individual frequency ranges without significantly altering other frequencies; so extreme settings are no problem with the Pultecs.

If you’ve never used a Pultec EQP-1A, the grouping of controls might be a little confusing. The EQP-1A can control three frequency ranges simultaneously, using three groups of interacting controls.

Control grouping within the Pultec EQP-1A
  1. The first group controls the low frequencies and has three controls: boost, attenuation, and frequency select. This section is a shelving EQ.
  2. The second group controls the high frequencies and has three controls: boost, bandwidth, and frequency select. This section is a parametric boost EQ.
  3. The third group also controls the highs and has two controls: attenuation amount and frequency select. This section is attenuation only shelving EQ.

Cool Trick
In the documentation supplied with hardware version of the EQP-1A, it is recommended that both Boost and Attenuation not be applied simultaneously to the low frequencies because in theory, they would cancel each other out. In actual use however, the Boost control has slightly higher gain than the Attenuation has cut, and the frequencies they affect are slightly different. The EQ curve that results when boost and attenuation are simultaneously applied to the low shelf is difficult to describe, but very cool: Perhaps the sonic equivalent of a subtle low-midrange scoop, which can add clarity. A great trick for kick drums and bass instruments.

With the MEQ-5, handy upper and lower midrange frequencies are now accessible for boosting, as well as the highly useful midrange parametric cut.

Straightforward in operation, the MEQ-5 is divided into three groups of controls.
All groups are fixed Q parametric. In general the Q is medium, but can be subtlety different depending on the frequency selected in each band. Total boost or cut range is 10 dB.

Control grouping within the Pultec MEQ-5
  1. The first group controls the lower midrange frequencies and has two controls: peak (boost) and frequency select.
  2. The second group controls the mid frequencies and has two controls: Dip (cut) and frequency select.
  3. The third group controls the upper midrange frequencies and has two controls: boost and frequency select.

-Will Shanks

Special Thanks to Irv Joel and Paul McManus

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