Benchmark MPA1

Clean Preamplification - Perfect for Stereo Pairs!

Benchmark designed the MPA1 to bring you two extremely transparent channels of audio. It's ideal for use with stereo pairs, ribbon microphones - and any application where you demand purity from your microphone preamplifier. The MPA1's unique stepped-input control lets you adjust gain in 38 steps, so you can adjust each of the two preamplifiers in the same way. Each step gives you 2dB, for a healthy total of 74dB of gain. And, for critical instrument miking applications, you can also expect excellent low-end phase accuracy, with Benchmark's MPA1.

• Carefully designed for purity and transparency
• Exceptional, phase-accurate low-frequency performance
• 38-position gain control for repeatable results
• Sophisticated phantom power protection

Benchmark engineered the MPA1 with transparency and purity in mind - its two channels are perfect for critical stereo-miking applications. Onboard, the input stage features 29dBu of high-voltage headroom, as well as single-stage gain control, to maximize the signal-to-noise ratio. To achieve this superb noise performance across the entire gain range, Benchmark uses precision-matched, low-noise, transistor quad-arrays, plus a servo-controlled circuit to minimize DC-offset and maximize headroom.

When you need accurate low-frequency performance, you can depend on Benchmark's MPA1 microphone preamplifier. It features a special dual-capacitor AC-coupling design, which defeats the limits of single-capacitor AC-coupling, ultimately giving you an exceptionally low corner-frequency with excellent subsonic phase accuracy.

The Benchmark MPA1 features a unique gain control circuit. It has a 38-position, switched-resistor ladder - for repeatable performance - that's set up in a continuously rotation orientation via relay control. Each step offers 2dB of gain, taking you from 0dB to 74dB of gain, without attentuation. It has an inter-channel gain precision of +/- .03dB, so you can count on the MPA1 for matched preamplification from channel to channel.

Benchmark equipped the MPA1 with protection from phantom power surges, via an ultra-fast, multi-stage protection circuit. This circuit takes advantage of the high-speed capabilities of low-capacitance Schotky diodes and the high-current capabilities of TVS diodes, to absorb the phantom power surges caused by shorts and plugging/unplugged microphones when phantom power is engaged. The circuit is pre-biased, as well, so it's isolated from the circuit when used normally, but activated if a surge occurs.

• 38-position discrete linear gain switching (2dB / step)
• Automatic gain-range switching with LED range-indicators
• 0-74dB total gain range
• Switchable 40Hz highpass filter (relay controlled - no audio through switches)
• Switchable polarity invert (relay controlled - no audio through switches)
• Independently switchable +48V phantom power
• HPA2 - Benchmark's signature high-current, 0-Ohm headphone amplifier
• 4-segment, precision LED meters (calibration-free)
• Recessed phantom switch to prevent accidental switching
• Phantom-power disable jumper for dedicated ribbon mic operation
• Phantom-protection circuitry prevents damage from phantom-power surges
• Internal, toroidal linear power supply
• High-quality gold Neutrik connectors
• Maximum input: +29 dBu
• Maximum output: +29 dBu
• Ultra-low noise/distortion: (THD+N @ 22dB Gain 10Hz-20kHz = 0.00045%)
• RF-immunity over a wide bandwidth (500kHz)
• Designed, built, and tested in Syracuse, New York, USA