Pultec EQP-1A3 Solid State Program EQ #14368 (Vintage)

The Pultec EQP-1A3 solid state program equalizer is the successor to the classic EQP-1A3 tube EQ. Housed in a 2U rack unit with a brushed metal faceplate, just like its tube predecessor. It uses an API 2520 op amp for the gain makeup instead of tubes, as Pultec switched from tubes to transistors shortly before they closed up shop.

Frequency settings

• Low band shelf 20 - 30 - 60 - 100 Hz
• Low band Boost from 0 to 13.5 dB
• Low band Attenuation 0 to 17.5 dB

• High bell 3 - 4 - 5 - 8 - 10 - 12 - 16 kHz
• High bell Boost from 0 to 18 dB
• High bell Bandwidth (Q) from 0 to 10 (0=sharp 10=wide)

• High shelf 5 -10 - 20 kHz
• Attenuation selector 0 to 16 dB cut

History

The name Pultec is an abbreviation of Pulse Techniques Inc., a company that consisted of two men: Gene Shenk and Ollie Summerland. These electronic wizards made every piece of their gear by hand at their factory in Teaneck, New Jersey, not far from Les Paul’s house. In fact they even collaborated with Les on some projects. Although they made a number of other products, (such as the MB1 Microphone Booster and PC-10 phono preamp), Pultec is most famous for their passive equalizers. Their EQ's were based on a design created by Gene Shenk (contrary to popular belief, only the negative feedback circuitry of the amplifier was licensed from Western Electric).

The original product, released in 1955, was the EQP-1, a passive equalizer with no gain make up stage. It was not until 1961 that the updated version was released, the EQP-1A. This model included some extra frequencies, and a tube gain stage to make up for the signal loss of the passive EQ circuit.

In 1971, Pultec introduced the EQP-1A3, which was identical in all respects to its predecessor the EQP-1A, except that it fit into a smaller, 2U rack unit, and bore a new brushed aluminum faceplate. These units were still tube based. It was not until many years later, near the end of their production years, that Pultec switched from tube designs to solid state. Thus all solid-state versions had a silver faceplate, but so did many of the later tube units.

The various EQ models produced by Pultec include the EQP-1, EQP-1A, EQP-1A3, EQP-1A3SS, EQP-1R, EQP-1RS, EQP-1S, EQP-1S3, HLF-3C, EQH-2, and the MEQ-5. With top-notch, hand-made craftsmanship and a unique sound, Pultecs remain one of the most sought after of the vintage passive equalizers.