Tube-Tech ME 1A Midrange Equalizer, First Take:
Midrange program equalizer with passive filters and tube-based gain-makeup amplifier
Three sections of selectable EQ
Balanced and fully floating I/O

Passive EQ with Tube Amplifier

The rackmount Tube-Tech ME 1B Midrange Equalizer contains a low frequency boost section for peaking, a mid frequency attenuation for dipping, and a high frequency boost section for peaking. The ME 1B contains a passive filter and a tube-based amplifier to restore the loss from the filter. The filter has a low frequency peak section with 5 selectable frequencies, a mid frequency dip section with 11 selectable frequencies, and a high frequency peak section with 5 selectable frequencies. The filter is placed directly after the input transformer, therefore eliminating noise from the amplifier when boosting either low- or high frequencies. The amplifier consists of two tubes in push-pull configuration (one ECC 83 as the pre-amp, and one ECC 82 as the output stage), and an output transformer. Both input and output are balanced (600_) and fully floating for maximum electronic isolation. The in/out key switches the equalization in and out without clicks and changes in level, while the amplifier remains in the signal path.

Three Frequency Sections

Using a bell curve EQ to isolate center frequencies, the ME 1B divides the midrange into three sections, low, mid, and high. The low frequency section comprises a continuously variable peak control (0dB to +10dB) and choice of five selectable frequencies (200Hz, 300Hz, 500Hz, 700Hz, 1kHz). The
Mid Frequency section comprises a Dip control that is continuously variable from 0dB to -10dB and eleven selectable center frequencies from 200Hz to 7kHz. The High Frequency section covers five selectable frequencies from 1.5kHz to 5kHz and a Peak control that is continuously variable from 0dB to +8dB.

Balanced and Fully Floating I/O

Both input and output are balanced (600 ohm) and fully floating, which provides maximum electronic isolation since there is no common ground between input and output. Input and output transformers come with a static screen between the primary and secondary wirings. These screens shield the secondary from the primary and prevent RF (radio frequency) electromagnetic noise from getting across.

About Tube-Tech

For over twenty years, Tube Tech has been one of the most prominent names in all-tube signal processing equipment. You’ll find their gear in the best recording and mastering studios around the world. The company’s founder, John Petersen is an electrical engineer who was factory trained at Solid State Logic, EMT, Studer, Sony, Neumann, and NTP Electonik (digital audio routers). He also designed tape recorder playback/recording amps for Lyrec tape recorders (found in the studios of the legendary Joe Meek and Vangelis). His first design under the name of Tube-Tech was an all-tube equalizer based on the legendary Pultec EQP 1A. Petersen continued to design and manufacture a number of innovative all-tube outboard processors including preamps, multiband compressors and summing amps. Thanks to John’s dedication to high-quality analog sound you’ll see Tube-Tech gear in the racks of pro audio legends such as multi Grammy Award winner Al Schmitt, (Frank Sinatra, Steely Dan, Toto, Quincy Jones, Natalie Cole, Diana Krall), Grammy winner Joe Chiccarelli, (Elton John, Beck, U2, Tori Amos, Counting Crows, Offspring), engineer Russ Long (Sixpence None The Richer, Wilco, Dolly Parton, Allison Moorer), producer-engineer Tony Shepperd (Elton John, Madonna, Kenny Loggins, Barbra Streisand, Lionel Richie, and Whitney Houston), and many more.