The BAE 1073 Mic/Line Preamp/EQ is a single-channel, 19-inch rack-mounted microphone and line-level preamplifier and equaliser, delivering 80 dB of all-Class A, transformer-balanced gain, built with entirely hand-wired circuitry and an external high-current PSU. Designed as a faithful reproduction of the legendary 1073 module, it matches the original in layout, componentry, and sonic performance, making it a premium signal path choice for professional studios.
Circuit Design and Components
Engineered with meticulous attention to the original 1970s design, the BAE 1073 integrates St. Ives (Carnhill) input and output transformers, Elma rotary switches, and Canford cabling—critical elements responsible for its renowned tonal characteristics. The unit’s hand-wired circuitry ensures low-noise, high-headroom operation with superior dynamic range. The preamp offers all-Class A discrete amplification throughout the signal path, with no ICs or surface-mount devices, preserving the sonic integrity favoured in classic analogue recordings.
Inputs, Outputs and Front Panel Functions
The front panel features a Hi-Z direct input, ideal for instruments such as electric guitars and basses, along with switches for engaging 48 V phantom power for condenser microphones. On the rear, the unit includes balanced XLR connections for mic input, line input, and +4 dBu output, enabling seamless integration into modern and vintage studio setups. The output level control can act as a fader, particularly useful when recording directly to tape or other line-level destinations.
Equalisation Section
The EQ section offers a high degree of tonal shaping flexibility. The high-frequency band provides a fixed 12 kHz shelving curve with ±16 dB of boost or cut. The low-frequency shelving band allows selection among 35 Hz, 60 Hz, 110 Hz, and 220 Hz, with the same ±16 dB range. The midrange section is a fixed-Q peaking filter with selectable centre frequencies of 360 Hz, 700 Hz, 1.6 kHz, 3.2 kHz, 4.8 kHz, and 7.2 kHz, and a ±18 dB gain range. An 18 dB/octave high-pass filter can be engaged at 50 Hz, 80 Hz, 160 Hz, or 300 Hz to eliminate unwanted low-end rumble or proximity effect.
Power Supply and Performance
The external oversized power supply delivers four times the current required by the unit, ensuring absolute headroom and transient clarity while avoiding voltage sag or sonic compromise. This design choice directly enhances tonal consistency and ensures the preamp performs at peak specification regardless of external power fluctuations.