There's something magical about holding a piece of audio history that literally changed the way we shape sound.
The Sontec MEP-250C EQ sitting on our bench at the Vintage King Tech Shop is a direct descendant of the world's first fully parametric equalizer.
Featuring parametric control over three bands plus high and low shelving, the MEP-250 delivers the warm, musical character that’s made it a prized piece of outboard gear for decades.
Keep scrolling to take a look under the hood and see what makes the Sontec so legendary. But first, let’s talk about how the MEP-250 came to be.
The ITI ME-230 Mastering Equalizer
The story behind the MEP-250 starts in 1958, when Sontec founder Burgess Macneal and a partner opened a recording studio using homemade tube equipment.
In the mid-1960s, Macneal met 16-year-old George Massenburg through Dean Jensen (of Jensen Transformers). Despite his young age, Massenburg proved to be exceptionally talented.
When their studio was sold to ITI (a company developing color movie cameras), Macneal and Massenburg were tasked with designing mixing consoles for the new facility.
The breakthrough came after weeks of struggling to create a satisfactory equalizer. Massenburg finally cracked the code during a late-night session and left a knife driven into Macneal's office door, holding a note that read "This is it, this works!"
The original equalizer was called the ME-230 (Mastering Equalizer 230) and sold for $1,460 in 1971. This was the world's first fully parametric equalizer, featuring the revolutionary ability to control bandwidth (Q).
Their live demonstrations at the 1971 AES show in New York created such a stir that crowds formed down the aisle and around the corner.
Over the years, the ME-230 would go through several iterations, including the MEP-230, which introduced pots for better construction.
The MES-230 was a fixed-frequency version of the ME-230, which used frequencies that Macneal and Massenburg selected by simply dividing up using a slide rule. Despite their lack of research, they did something right because these same frequencies are still used today.
The Birth Of The Sontec MEP-250
After years of financial struggles, ITI was liquidated in January of 1975 and held an auction to sell off its remaining assets. George Massenburg (backed by Earth, Wind & Fire) bought the big studio, while Macneal purchased the pressing plant.
Most importantly, Macneal bought all the equalizer engineering, drawings, and parts for just $75, essentially acquiring the entire ITI equalizer business for pocket change.
Operating from their small house with his wife doing assembly, Macneal restarted production as Sontec. The first customer was the legendary Sterling Sound, and word spread quickly through the mastering community.
The Sontec MEP-250 went through several iterations, including the MEP-250A, MEP-250B, and MEP-250C. Much like the early ITI models, the MES (Mastering Equalizer Switches) Series EQs featured fixed frequencies and stepped level controls, making it ideal for mastering. In fact, the MES-430 and MES-432 are still seen as "holy grail" mastering compressors to this day.
Around 1987, several of the key components used in the Sontec design were discontinued. Some time later, Sontec reissued the classic MEP-250 as the MEP-250EX, featuring modern components.
About The Sontec MEP-250C
The MEP-250C that came through our shop represents the culmination of that design lineage: a five-band stereo EQ that’s become a staple in mastering studios around the world.
With fully sweepable low, mid, and high bands plus switchable shelves at the top and bottom, the 250C is known for its musical response, subtle coloration, and surgical precision.
Frequencies
- Lo Shelf: 15 - 800 Hz
- Lo: 15 - 620 Hz
- Mid: 120 Hz - 8.2 kHz
- Hi: 400 Hz - 26 kHz
- Hi Shelf: 1.2kHz - 32 kHz
- Level: +/- 12db, with '0' position detent on each band
