Mäag Audio’s newest creation is the PREQ2™ Dual Mic Preamp with EQ, a complete analog system for either recording or mixing housed in a 1U standalone unit. It comes with Cliff Mäag’s venerable Air Band® shelving equalizer first introduced in 1993 with his NTI EQ3 equalizer.
The PREQ2 will handle either line or microphone signal levels with two matched channels both with separate rear panel line level input and microphone XLR connectors and switchable +48-volt phantom powering. The rear panel also has XLR output connectors for each channel and a on/off/fuse mains switch.
All switches on the PREQ2 have colorful LEDs to confirm their operation and all controls have detents with the exception of the continuously variable microphone gain.
Microphone Input
The Mäag Audio PREQ2 microphone preamp has up to 71dB of gain split between a discrete Class-A transistor preamp along with a large, nickel-core Mäag Audio-built input transformer (one for each channel). This circuit offers a clean, detailed sound with +27dBu of headroom and an EIN noise level of -128dB. There are two optimized gain ranges selectable on the front panel. The default gain range is +20db to +42dB and a +42 to +71dB gain range in high gain mode using the front panel’s 25dB gain switch. Maximum input level is +8dB.
The Microphone Input section has front panel switches, LED indicators and buttons for: +48-volt phantom powering, -20dB attenuation pad, plus signal present, +26dBu peak LEDs, and phase or polarity flip. Microphone gain is continuously adjustable using a single, large mic gain control knob.
Line Input
The front panel Line switch toggles the rear panel XLR line input connectors in place of the microphone preamp’s output (after the input transformer and microphone preamp). It is possible to keep both a microphone and a line level source always connected to the PREQ2 and toggle both channels separately. You could have one channel working as a microphone preamp channel and the other as a line level amplifier for recording a direct musical instrument (bass or guitar) at the same time.
Both mic input sections have ¼-inch TS jacks for high impedance (1 mega-ohm) instrument input with a companion ¼-inch output Thru jack that simultaneously provides an isolated, buffered output—a “copy” of the instrument input signal at unity gain. In addition to providing an unbalanced signal for running long leads out to instrument amplifiers in the studio and/or stomp pedals, for live re-amplifying the Thru jack’s output signal is also active when using the XLR microphone input.
When using the instrument input TS jack, the Mäag Audio PREQ2 uses an automatic detection circuit to switch (using a relay) and route the unbalanced ¼-inch input signal to the mic input transformer. The impedance is lowered for a better match to the transformer. This detection circuit makes it is impossible for the 48-volt phantom power to ever reach the ¼-inch or XLR Line input even if already turned on.
Equalization Sections
The Mäag Audio PREQ2 has three equalizer/filters sections; the layout and control compliment are identical for both channels. The equalizer design is specifically designed for both recording and/or subtle touchup tonality changes and euphonic enhancements.
On the left side of the channel is the first control for the 2nd order, 12dB/octave high pass filter. It is fully variable using a 21-detent control to sweep from 20Hz to 200Hz. It has its own hardwired, in/out bypass switch.
Next is the Low Frequency bell-shaped equalizer section with a boost (only) control at 6dB/Octave. Frequencies are switched using a six position rotary switch and are: 10Hz (Sub) shelf, and bell-shaped curves for 40Hz, 65Hz, 100Hz, 125Hz, and 165Hz. Up to 9dB of boost is available.
Air Band®
The third band of the equalizer is the Mäag Audio Air Band shelving section with 2.5, 5, 10, 15, 20, and 40-kHz frequency choices with its own control and up to 9dB of maximum boost. Both the Air Band and Low Frequency equalizers share a single bypass push-button.
Specifications
- Noise level at the lowest gain setting is -100dB. EIN is -128dB
- Balanced XLR Output Head room is +27dbu
- The microphone transformer feeds a differential set of front-end class A discrete transistors paired with a FET input Operational Amplifier
- High and Low Gain push button switch. Low range: +20db to +42db. High range (Gain +25 Switch w/Green LED) +42db to +71db
- Switchable -20db Pad w/Green LED
- +48 Volt Phantom Power, Switchable, w/Red LED
- Phase Reversal Switch: Switches the Phase of the Balanced Output
- Green signal present LED, Red Peak LED lights at +26dbu
Mäag Audio PREQ2 Manual
