The Sytek EQ4X-M1 Four-Band Parametric Equalizer and 1-channel Microphone Preamplifier.

Description

The EQ4X-M1 equalizer is a four band, auto-stabilized true state variable filter Bessel Polynomial (less phase shift) with no interaction between frequency and "Q", maintained over the full amplitude range.

It simultaneously can provide peak and dip for low pass, high pass, band pass with peak, shelving and notch (positive- and negative-going mid-band) functions with fully symmetrical curves. Its gain, frequency, and Q (narrowness of band) can also each be independently controlled.

The one channel microphone preamp is a hybrid transformerless design which exceeds the performance of the best transformer design in low level input applications. It achieves low noise, minimum distortion, wide bandwidth linear phase response and a warm sound, with crystal clear sound and an ultra-fast response. The input stage of the microphone preamp is based on a Class A auto-Bias bridge configuration using selected low noise transistors for perfect balance, low impedance, and fast slew rate.

Controls

A dual concentric potentiometer for each of the four bands controls the frequency (outer dial) and the amplitude of cut/boost (inner dial). A switch on the right side of the dual concentric potentiometer for LOW band (LF) and HIGH band (HF) changes from PEAK to SHELF mode, changing bandpass to high- or low-pass. The MID band LMF and HMF (low- and high-middle frequencies) have in the left side one control potentiometer each to allow continuous bandwidth selection from 0.3 to 2.5 octaves, providing control from the broadest influence to the sharpest notch (or peak).

The microphone preamp section contains controls for MUTE, PHASE, +48V Phantom Power, as well as MIC/LINE and EQ-IN for turning ON or OFF of the equalizer function. A patchpoint settable elsewhere allows the equalizer, when switched mostly out of service, to still provide a low-band suppression function in order to make best use of other possible equipment that might otherwise introduce a spurious "rumble" effect when processing the lowest frequency components in the absence of the equalizer's regular low-band filtering.

A PEAK indicator shows the remaining headroom before clipping the signal output (set at -8dB).

Frequency adjustment ranges (bands)

Specifications