Pultec Passive EQ Plug-In Collection.
Basics and FAQ.
How does the new Pultec Passive EQ Collection compare to the previous Pultec plug-ins offered by Universal Audio?
The plug-ins in the Pultec Passive EQ Collection benefit from the additional processing power afforded by the UAD-2, plus more than 10 years of UA’s evolving sophistication in plug-in design. While our original Pultec plug-ins remain an excellent rendition of the hardware, the new Pultec Passive EQ Collection plug-ins add the transformer and complex tube amplifier nonlinearities to these must-have tools. The sophisticated modeling technology used today in this new plug-in collection captures all of these tone-enhancing characteristics for individual sources to full program material.
Does the Pultec Passive EQ Collection replace the "old" Pultec plug-ins?
No, the original Pultec EQP-1A Legacy plug-in will continue to be included in the “Analog Classics” bundle, which is provided with the purchase of any UAD DSP product. The UAD Pultec EQP-1A (Legacy) and UAD Pultec-Pro (Legacy) remain useful, in that they consume less DSP, and are less sonically “colored” — which may be desirable in some instances.
Can I still purchase the “old” Pultec-Pro plug-in?
For the few UAD customers who do not already own the UAD Pultec-Pro (Legacy) EQP-1A/MEQ-5 combo plug-in, they will get it as a fourth plug-in title with the purchase of the Pultec Passive EQ Collection.
The layout of the EQP-1A is a bit confusing. What are the parameter associations?
The EQP-1A is a three band EQ with a layout that may be less than intuitive to a new user. Here’s a visual breakdown of the controls associated with each of the bands; Low Shelf, High Peak and High Shelf.
The Low shelf can be boosted and/or attenuated for a special effect that creates a shelf boost with a resonant dip near the cutoff frequency. The High Peak filter can be boosted along with an adjustable bandwidth or Q, while the High Shelf is attenuation only.
How does the EQP-1A boost and cut the same frequency?
In the documentation supplied with original hardware EQP-1A, it is recommended that the 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. Really, there are two shelf filters present that can interact due to the fact that the Pultec is a passive EQ with no buffering between the boost and cut filter stages; this allows the boost and cut filters to be tuned in their interaction with each other, and the cut becomes a slightly resonant dip along with the shelf boost.
What defines a passive EQ design, and why is it special?
A passive EQ is a variable equalizer requiring no external power to operate, consisting only of passive components. Passive designs are favored for their high dynamic range, low noise, and reliability. The downsides of passive designs are insertion loss (the signal gain is significantly reduced) and frequency roll-off (depending on impedance). The Pultec HLF-3C is such a design (but is gain compensated in the plug-in). The EQP-1A began life as the fully passive EQP-1, but the updated EQP-1A was fitted with tube amplification and transformer isolation to make up for the insertion and frequency loss. Make-up amplifiers are now common to most modern passive EQ designs, like the Manley Massive Passive