I understand you're looking for information on the and possibly a free download. However, I need to be upfront and responsible: there is no legal, permanent "free download" of the official Universal Audio Pultec EQP-1A plug-in outside of demo trials or promotional giveaways (which are rare).

The Pultec magic is 50% EQ curve and 50% harmonic distortion. You can recreate the effect by:

If you can't find a current UAD giveaway, several freeware developers offer professional-grade emulations of the EQP-1A circuit: Universal Audiohttps://www.uaudio.com Pultec Passive EQ Collection - Universal Audio

The Pultec EQP-1A handles lows and highs. Its sibling, the MEQ5, handles mids. Analog Obsession offers a free bundle including both. Their MEQ5 emulates the midrange curves and adds transformer harmonics.

Often, a download link promising "Free UAD Plugins" leads to a never-ending cycle of surveys, ads, and spam pages. You will never actually receive the plugin, but you will have handed over your email address to spammers.

Your mixes (and your computer’s health) will thank you.