This equalizer uses passive LC circuitry with class-A triode vacuum tube stages for the input and output. The tube circuitry is largely derived from the VT-1/VT-2 mic preamp design, so the equalizer has much the same sonic character as the preamps.
The LC-style passive equalization circuitry is based on the classic designs that are still the best-sounding way to achieve high-quality tonal control.
The input is line-level, transformer balanced-bridging. An active vacuum tube input section has adjustable gain to accommodate input signals as low as -10 dBm. The input transformer is made by Jensen. The output stage utilizes the same custom Jensen transformer used on the VT-1/VT-2 mic preamps.
All controls are stepped for precise repeatability and uniform matching between units. High-quality rotary switches are used with 1% metal-film resistors. All of the audio capacitors are polystyrene or polypropylene. The inductors are custom-made for us by Jensen Transformers Inc.
The equalizer is constructed of heavy-gauge aluminum, with a 3RU (5.25 inch), 1/4-inch thick front panel, finished in D.W. Fearn red. It matches the VT-1/VT-2 series of mic preamps in appearance and construction.
Like the VT-1/VT-2 preamps, the Equalizer has been designed to provide an exceptional tool for audio professionals. The design frequencies and curves were determined by ear, after extensive listening to a variety of program material, both individual tracks and overall mixes. The result is a highly-musical equalizer with plenty of range for enhancing any track or mix.
Frequency response: +/- 0.2 dB 20 Hz to 20 kHz
THD: less than 0.06%
Signal-to-Noise: better than 80 dB
(All controls are independent and can be used in any combination)
Low Cut at 30, 40, 100, or 400 Hz, 0 to -18 dB shelving in 2 dB steps
Low Boost at 20, 40, 60, or 140 Hz, 0 to 16 dB shelving in 2 dB steps
Mid Cut at 200, 300, 400, 500, 600, or 700 Hz, 0 to -16 dB in 2 dB steps
High Boost at 1.5, 3, 4, 5, 8, 10, 12, or 16 kHz, 0 to 12 dB in 2 dB steps
High Bandwidth Q of 0.6, 0.8, 1.0, 1.4, or 1.7
High Frequency Cut at 1.5, 3.5, 8, or 28 kHz, 0 to -14 dB shelving in 2 dB steps
Gain adjustable from -9 to +9 dB, referenced to +4 dBm, in 3 dB steps
NOTE: Frequency is specified in cycles per second (cps) or kilocycles per second (kc). These units correspond to Hz and kHz respectively. Measurements made with -50 dBm input and 50 dB gain in a 22 cps to 22 kc bandwidth. Specifications and price subject to change without notice.