Pultec Passive EQ Collection Manual

Astonishingly accurate recreations of the "must-have" classic EQs

Building on a decade of the world's most intensive modeling research, UA has recreated the famed Pultec EQ experience as plug-ins — ones that are nearly indistinguishable from the original analog hardware.

The Pultec Passive EQ Plug-In Collection for UAD Spark and UADx includes the ultimate plug-in emulations of Pulse Techniques' original passive EQs. With painstakingly modeled amplifier sections now onboard, the Pultec EQ Collection "breathes" like the original hardware.

  • Use Pultec's three most popular studio EQs on individual tracks or buses
  • Make difficult-to-isolate instruments and vocals breathtakingly clear without affecting neighboring frequencies
  • Provide the same Pultec analog "magic" for your tracks, making them sound
    better just by passing through
  • Dial up extreme levels of EQ boost while staying natural and musical
  • Push the Pultec's fully modeled transformer and tube-based amplifier sections
  • Give that signature airy, smooth-as-silk vintage tone to your master channel

The Pultec Story

When Ollie Summerland and Gene Shenk hand-crafted the first Pulse Techniques passive program equalizer in 1951, they had no idea they were transforming an industry. But like a Stradivarius, their little garage-built, made-to-order designs have been copied by nearly every EQ-maker for decades, and their early EQP-1A's still bring thousands on the used market — if you're lucky enough to find one.

Legendary Pultec Depth and Clarity

Going far beyond UA's original standard-defining Pultec plug-ins, the EQP-1A faithfully models the overbuilt transformers and complex tube amplifiers of the original hardware. Simply running a full mix or single instrument through it imbues the track with the legendary Pultec analog magic. And, with these new plug-ins, you can actually hear the Pultec's amplifier overload effects — just as you would with the hardware — unleashing a bounty of sublime results.

The Signature Effect on Low End

The Pultec EQP-1A's signature effect, unintended by its designers, is its ability to seemingly boost and cut the same frequency simultaneously. In reality, the filters actually alter adjacent frequencies, but the naturally interactive resonant dip has an amazing boosting and tightening effect — especially on bass guitar and kick drums.

Shaping Your Mids: The MEQ-5

The MEQ-5 Mid-Range Equalizer is the richly colorful tube-amplified companion to the EQP-1A. With two bands of midrange boost and one band of midrange dip, the MEQ-5 gets the very best out of the "power region" where guitars and vocals can make or break a mix. The unique band overlap and filter interaction unleash the vibrancy of these instruments in the track — without fighting your overall mix.

Tame The Sides: The HLF-3C

The never-before-available HLF-3C completes the Pultec Passive EQ Collection. This new plug-in adds 12 dB per octave low and high cut filters, for broad retro-tonal sculpting or bygone-era special effects. You can easily subtract the unnecessary frequencies in any instrument and sub-group so they stay wonderfully musical in the mix.

Artist Presets

In developing the Pultec EQ Collection, UA commissioned some of the biggest names in the business to develop custom presets. Check out John Paterno's (Steve Gadd, The Black Crowes, Bonnie Raitt) "Clear, Big-Body Acoustic" and his "U-47" and "U-67" settings. Also demo Jacknife Lee's (The Cars, U2, Taylor Swift) "Drum Buss Earth and Air" and "Acoustic Guitar Tamer."

 

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Pultec EQP-1A interface

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Pultec MEQ-5 interface

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Pultec HLF-3C interface

 


 

Pultec Passive EQ Collection

The Pultec Passive EQ Collection provides access to three historical and highly coveted revisions in the Pultec product line.

The plug-ins in the Pultec Passive EQ Collection benefit from more than 10 years of UA's evolving sophistication designing plug-ins. The plug-ins in the Pultec Passive EQ Collection include the transformer and complex tube amplifier nonlinearities for extreme authenticity. The sophisticated modeling technology used in this plug-in collection captures all of these tone-enhancing characteristics.

Pultec EQP-1A

Used on a myriad of recordings from the 1950's to today, the three-band, tube-amplified EQP-1A Program Equalizer has long been a studio staple of recording and mix engineers for its ability to bring out individual frequency ranges without significantly altering neighboring frequencies. This unit is equally famous for its ability to dial in seemingly dangerous amounts of boost and famously smooth-as-silk vintage tone. The EQP-1A is also known as the quintessential "magic" studio piece that makes audio simply sound better just by passing through it.

Pultec MEQ-5

The Pultec MEQ-5 Mid-Range Equalizer is the richly colorful tube-amplified companion piece to the EQP-1A. With two bands of midrange boost and one band of midrange dip, the MEQ-5 is designed to enhance and control the "power region" where sound energy is often concentrated, covering the finer tone requirements in the Pultec Collection with an abundance of band overlap and filter interaction.

Pultec HLF-3C

The HLF-3C completes the Pultec Passive EQ Collection. This plug-in has 12 dB per octave low and high cut filters, providing broad retro-tonal sculpting or bygone-era special effects, without the inconvenience of insertion loss found with the unamplified passive hardware.

 


 

Operational Overview

The Pultec EQP-1A/MEQ-5 combination is still standard fare in recording studios and was once widely used in mastering sessions. Whether used independently or together, mono or stereo, the Pultec Collection provides a complete vintage EQ palette for individual sources such as bass or kick drums, subgroups such rhythm, horn or string sections, or on the master bus. The EQP-1A's 16 KCS high frequency setting is famous for adding "air" to master sources.

Although unintended by its designers, the Pultec EQP-1A is coveted for its unique ability to boost and cut the same low frequency simultaneously, creating a tightening effect as a naturally interactive resonant dip near the selected frequency. This has the sonic effect of simultaneously tightening and boosting bass frequencies. Select the bass frequency then adjust the balance of Boost and Cut to tune the effect.

EQP-1A Insertion Boost

The original EQP-1A hardware unit has an inherent level boost of approximately 1.13 dB when it is in the signal path. This inherent boost is present in the EQP-1A plug-in models as well.

Frequency Conventions

The original Pultec hardware used frequency unit names that were conventional before the frequency unit of "Hertz" was widely adopted. The UAD Pultec plug-ins adopt the original frequency unit name conventions.

CPS is an acronym for Cycles Per Second, which is now more commonly referred to as Hertz and abbreviated as Hz. KCS is an acronym for KiloCycles per Second, which is now more commonly referred to as KiloHertz and abbreviated as kHz.

 


 

Pultec EQP-1A Controls

Control Grouping

The EQP-1A can control three frequency bands simultaneously, using three groups of interacting parameters.

The first group adjusts the low frequencies and has three controls: boost, attenuation, and frequency select. The second group adjusts the high frequencies and has three controls: boost, bandwidth, and frequency select. The third group also adjusts the highs and has two controls: attenuation amount and attenuation frequency select.

The placement and grouping of the sections and their related controls are shown below.

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Control grouping within the Pultec EQP-1A

EQ Enable

This is the EQ enable control. Like the original hardware, the signal is still colored even when this switch is in the out (down) position, because the signal is still passing through the I/O circuitry. If a true bypass is desired, use the Bypass/Gain knob.

Bypass/Gain

Rotate the control fully counter-clockwise to disable plug-in processing and reduce processing load.

Tip: Click the OFF text label or the red power lamp to toggle between bypass and the previous value. Click the "0" text label to set the gain to 0 dB.

Low Frequency Controls

Low Frequency

This switch determines the frequency of the low shelf portion of the equalizer. Four frequencies are available: 20, 30, 60, and 100 CPS.

Tip: To cycle through the available values, click the CPS text label, or shift+click the text label to cycle through available values in reverse. This function is unavailable with the Legacy version of the plug-in.

LF Boost

This knob determines the amount of low shelf gain to be applied to the frequency set by the CPS switch.

LF Attenuation

This knob (ATTEN) determines the amount of low shelf cut to be applied to the frequency set by the CPS switch.

Background

In the documentation supplied with hardware version of the EQP-1A, it is recommended that both Boost and Attenuation not be applied simultaneously 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 too. The EQ curve that results when boost and attenuation are simultaneously applied to the low shelf is an additional feature.

High Boost Controls

High Frequency

This switch determines the frequency of the high boost portion of the equalizer. Seven frequencies are available: 3, 4, 5, 8, 10, 12, and 16 KCS.

Tip: To cycle through the available values, click the KCS text label, or shift+click the text label to cycle through available values in reverse. These shortcuts are unavailable with the Legacy version of the plug-in.

HF Bandwidth (Q)

This knob sets the proportion of frequencies surrounding the center frequency (determined by the KCS switch) to be affected by the high boost (this is a bandwidth control). Lower values yield a narrower band and effect fewer frequencies.

HF Boost

This knob controls sets the amount of gain for the high frequency portion of the equalizer.

High Attenuation Controls

HF Attenuation Frequency

This switch (ATTEN SEL) determines the frequency of the high frequency attenuator. Three frequencies are available: 5, 10, and 20 KCS.

Tip: To cycle through the available values, click the ATTEN SEL text label, or shift+click the text label to cycle through available values in reverse. These shortcuts are unavailable with the Legacy version of the plug-in.

HF Attenuation

This knob (ATTEN) determines the amount of high shelf cut to be applied to the
frequency set by the Attenuation Selector switch.

 


 

Pultec MEQ-5 Controls

The MEQ-5 can control three frequency bands simultaneously, using three groups of interacting parameters.

The first group adjusts the low-mid frequencies and has two controls: frequency select and boost. The second group adjusts the mid frequencies and has two controls: frequency select and attenuation. The third group adjusts high-mids and has two controls: frequency select and boost. The placement and grouping of the sections and their related controls are shown below.

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Control grouping within the Pultec MEQ-5

EQ Enable

This toggle switch is the EQ enable control. Like the original hardware, the signal is still colored even when this switch is in the out (down) position, because the signal is still passing through the I/O circuitry. If a true bypass is desired, use the Bypass/Gain knob (MEQ-5) or the Enable switch (Pultec-Pro Legacy).

Low Peak Controls

LM Frequency

This switch determines the frequency of the low-midrange portion of the equalizer. Five frequencies are available: 200, 300, 500, 700, and 1000 CPS.

Tip: To cycle through the available values, click the PEAK text label, or shift+click the text label to cycle through available values in reverse. These shortcuts are unavailable with the Legacy version of the plug-in.

LM Boost

This knob determines the amount of low-midrange gain to be applied to the frequency set by the low-midrange frequency selector.

Dip Controls

Mid Frequency

This switch determines the frequency of the midrange portion of the equalizer. Eleven frequencies are available: 200 CPS, 300 CPS, 500 CPS, 700 CPS, 1 KCS, 1.5 KCS, 2 KCS, 3 KCS, 4 KCS, 5 KCS, and 7 KCS.

Tip: To cycle through the available values, click the DIP text label, or shift+click the text label to cycle through available values in reverse. These shortcuts are unavailable with the Legacy version of the plug-in.

Mid Dip

This knob determines the amount of midrange cut (attenuation) to be applied to the
frequency set by the midrange frequency selector.

High Peak Controls

HM Frequency

This switch determines the frequency of the high-midrange portion of the equalizer. Five frequencies are available: 1.5, 2, 3, 4, and 5 KCS.

Tip: To cycle through the available values, click the PEAK text label, or shift+click the text label to cycle through available values in reverse. These shortcuts are unavailable with the Legacy version of the plug-in.

HM Boost

This knob determines the amount of high-midrange gain to be applied to the frequency set by the high-mid frequency selector.

Bypass/Gain

This is dual purpose knob is an output gain control, and a plug-in bypass control. The available output gain range is ±12 dB.

Rotate the control fully counter-clockwise to bypass plug-in processing and reduce processing load.

Tip: Click the OFF text label or the red power lamp to toggle between bypass and the previous value. Click the "0" text label to set the gain to 0 dB.

 


 

Pultec HLF-3C Controls

Unity Gain

The Pultec HLF-3C hardware unit is a true passive design; there are no input/output amplifiers and it does not require any external power. As a result, there is an inherent loss of signal level when using the HLF-3C hardware.

The Pultec HLF-3C plug-in compensates for this inherent signal loss for simplified use in the modern era; it has unity gain upon insertion (there is no insertion loss until one or both of the cut filters is engaged).

The HLF-3C interface is very simple and includes only three controls.

Enable

This toggle switch is the plug-in bypass control. When in the down position (bypassed), plug-in processing is disabled altogether. The plug-in is engaged with the switch is in the up position.

This switch can be used to compare the processed settings to that of the original signal, or to bypass plug-in processing to reduce processing load.

Note: The behavior of this toggle switch differs from the other UAD Pultec plug-ins. Because the HLF-3C hardware is not internally amplified, there is no I/O circuitry modeling to maintain when the EQ portion of the circuit is bypassed (the entire hardware unit is the EQ portion).

Low Cut

This rotary switch specifies the cutoff frequency of the low cut filter. Eleven frequencies are available: 50, 80, 100, 150, 250, 500, 750, 1000, 1500, and 2000 CPS.

Tip: To cycle through the available values, click the CPS text label, or shift+click the text label to cycle through available values in reverse.

High Cut

This rotary switch specifies the cutoff frequency of the high cut filter. Eleven frequencies are available: 1.5, 2, 3, 4, 5, 6, 8, 10, 12, and 15 KCS.

Tip: To cycle through the available values, click the KCS text label, or shift+click the text label to cycle through available values in reverse.

 


 

History

In 1951, Pulse Techniques introduced the first passive Program Equalizer, the EQP-1. The passive EQ filter designs were originally licensed from Western Electric. Founders Ollie Summerland and Gene Shenk made up the Teaneck, New Jersey operation of Pultec. These two men comprised the engineering, marketing, sales and production staff for the entire history of the company, and made every item to order, all by hand. With the EQP-1A, Pultec improved the original design with tube amplification to overcome the typical insertion loss of passive equalizers. The EQP family of EQs would see many iterations, but the fundamental design would be Pultec's flagship product until the company's closure in the early 80s.

he Pultec Passive EQ Collection original hardware

The Pultec Passive EQ Collection original hardware

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