The PE 1C is a passive, all-tube EQ, based on the classic PULTEC EQP 1A design and featuring a passive EQ section and a high quality op amp. With the original Pultec out of production for decades and used examples demanding sky-high prices, the PE 1C is by far the easiest way to achieve this unique and coveted sound.
The PE 1C low end section combines two separate passive EQ filters with slightly different cut/boost frequencies. When the two sections are combined, this results in truly unique EQ curves, often named the “Low End Trick” and very useful for cleaning up low/mid frequencies.
The high frequency and midrange bands really stand out in terms of transparency and clarity, and the PE 1C is broadly regarded as one of the world’s finest passive tube based equalizers.
History and Details
“The Tube-Tech program EQ PE1A is exactly the same as Pultec program EQ!”
This was our message when promoting the very first Tube-Tech equalizer back in 1985.
The Tube-Tech PE1A program equalizer was originally made as a European exact equivalent of the US Pultec program eq EQP1A, that became very popular in the US during the eighties in recording studios in New York and LA. The smooth sound of the Pultecs made these eq”s very different and attractive.
The challenge of this illusive sound motivated Tube Tech founder and designer John Petersen to design and manufacture something that sounded just excately the same, featuring equal specs for all components .
The magic test was mixing with Pultec EQ1PA on the left channel and Tube Tech PE1A on the right channel and check the stereo image: It had to remain perfect on all settings!
The PE1A was the first product carrying the TUBE-TECH name 28 years ago.
Features and Technical Specifications
The TUBE-TECH PE1C is a passive tube based program equalizer based on the design of the old PULTEC EQP1A, featuring an all passive eq section and a high quality op amp. All components used are of the highest standard.
The TUBE-TECH PE 1C Program Equalizer contains a low frequency boost and attenuation section (shelving), and a high frequency boost section (peaking). The high frequency section has variable bandwidth as well as attenuation (shelving). The filter section is of the passive type followed by a tube based push-pull amplifier to restore the gain.
Input and output are transformer balanced as well as fully floating. Input and output transformers come with a static screen between the primary and secondary wirings.
- Tube based push-pull amplifier
- Freq. resp. @ -3 dB: 5 Hz – 40 kHz
- Low noise: < -85 dBU @ 0 dB gain
- CMRR: > 60 dB @ 10 kHz
- All-tube passive EQ
- 4 LF frequencies: 20, 30, 60 and 100 Hz (Boost: 0 to +14 dB, attenuation: 0 to -18 dB)
- 10 HF boosts with variable bandwidth: 1, 1.5, 2, 3, 4, 5, 8, 10, 12 and 16 kHz (0 to +18 dB w/ sharp Q, 0 to 10 dB w/ broad Q)
- 3 HF attenuations: 5, 10 and 20 kHz (0 to -18 dB)
- Input impedance: 600Ω
- No insertion loss
- Clickless In/Out switch
- Conductive plastic potentiometers
- In- and output are transformer balanced and fully floating
The sound samples on this player also covers the sound of the modular PE1C: EM1A, since the circuits and sound in the two units are exactly the the same.
EQ shootout, featuring the PE1C at 10:55.
FAQ: Program EQ PE1A, PE1B and PE1C Differences
- The amplifier section in the PE 1A and PE 1B is hardwired.
- In the PE 1C the transformers and the tubes are placed inside the unit on a printed circuit board.
- The filter section for the low BOOST/ATTEN and the high ATTEN is the same for all three units.
- The high boost in the PE 1B and PE 1C has three additional frequencies: 1, 1.5 and 2 KHz
Today the Tube-Tech PE1C is still in production, with little changes in sound from its original design.
The PE1C is one of the very few program eq that does exactly the same thing as the original Pultecs did when new.
We write “did” because today the Pultecs often are more “grainy” sounding today due to age and very old components. The high end boost of the PE1C is a one off a kind and nothing comes close.
Try it on dark sources like a Coles ribbon mike and hear how nice the top end gets opened up without harshness.
The sound obtained with the PE1C is impossible to get with other standard active eq”s due to the filter types, the tube gain stages and transformers.
There’s a lot of creative possibilities and magic hidden in this seemingly simple EQ: The low end section is a combination of two separate passive eq filters with a little different cut/boost frequencies, even though the front panel shows the same frequencies for these functions.
In reality the boost frequencies are a little lower than the attenuation frequencies, something the original Pultecs did and the Tube Tech carries over.. “THE LOW END TRICK” This feature results in special eq curves when the two sections are combined.
“THE TOP END” A smooth top end on sources is the key to improved definition without getting “bright”or agressive. This is very hard to accomplish with modern active eq’s.
The PE1C features extended mid/hi boost ranging from 1 Khz to 16 Khz.
Overall this smooth passive eq is equally suited to many jobs in the studio, from opening up vocals and guitars to eqalizing bass drums in the most exciting way.
PE1C is NOT a dirty sounding tube equalizer, and so wasn”t the Pultec. Classic well built Tube gear always featured extended frequency response and open sound. This is what can be achieved with well designed Tube Based Circuits and it’s the backbone of the TUBE-TECH sound.