RDL HR-MP2A Dual Microphone Preamplifier

Dual Microphone Preamplifier

The HR-MP2A is a dual channel microphone preamplifier with line-level outputs. Each section provides identical rear-panel signal connections and front-panel controls.

Each preamplifier is equipped with a front-panel INPUT PAD switch that allows the operator to attenuate the input signal by 15 dB prior to the preamplifier input stage, increasing the maximum input level from +5 dBu (attenuator out) to greater than +20 dBu. A POLARITY switch provides signal polarity reversal if needed. The GAIN control provides continuous adjustment between 20 dB and 60 dB. A CLIP LED flashes if a signal peak is within 3 dB of clipping. The trigger threshold of the CLIP LED is 17 dB above a normal +4 dBu output.

The HR-MP2A offers exceptional input headroom, wide flat frequency response and extremely low noise with very high common-mode signal rejection. Total harmonic distortion and crosstalk are below the noise floor, allowing the HR-MP2A to be operated as a stereo preamplifier or as two separate mono preamplifiers.

Each preamplifier provides two balanced line-level output formats: Detachable terminal block and 1/4" TRS. A separate summing amplifier provides a combined mono output on a line-level detachable terminal block. Balanced outputs may be wired unbalanced. The rear panel also provides a detachable terminal block and a power input jack to connect 24 Vdc power.

The HR-MP2A is constructed in a durable half-rack-width shielded metal enclosure for free-standing use or for mounting in an RDL rack adapter, available separately.

Features:

• Two Independent Microphone Preamplifiers
• Balanced XLR Microphone Inputs
• Independent Controls for Each Preamplifier
• Front-Panel 20 to 60 dB Gain Control
• Switch-selectable 48 Volt Phantom
• Switch-Selectable 15 dB Input Pad
• Switch-Selectable Polarity Reversal
• Switch-selectable 48 Volt Phantom for Both Preamplifiers
• CLIP Indicators for Peaks 3 dB Below Clipping
• Balanced Line-Level Outputs
• Each Output Allows Balanced or Unbalanced Connection
• Each Preamp Output on 1/4" TRS or Detachable Terminal Block
• Separate Summed Output 1 + 2 on Detachable Terminal Block

Specifications:

• Inputs (2): XLR (3 pin, rear panel,1=GND, 2+, 3-)
• Input level (for +4 dBu output): -56 dBu to 0 dBu (maximum gain without pad, minimum gain with pad)
• Maximum Input Level: >+5 dBu (input pad disabled), +22 dBu (input pad enabled)
• Input Impedance: < 1 kΩ balanced
• Phantom power: Switchable (both preamplifiers) 48 V phantom (IEC 1938: 1996-12)
• Input pad (2): 15 dB nominal (1 per preamplifier)
• Outputs (5): Each preamplifier (rear-panel): Detachable terminal block, 1/4" TRS Mono sum (rear-panel): detachable terminal block
• Output level: +4 dBu balanced, -4 dBV unbalanced; +24 dBu maximum balanced
• Output Impedance: 150 Ω balanced
• Channels: 2 (1 and 2; may be used for stereo or as two separate mono preamplifiers)
• Gain Trim (2): 20 dB to 60 dB (front panel adjustable; one for each preamplifier)
• Frequency Response: 10 Hz to 70 kHz (+/- 0.5 dB)
• THD: Below noise floor
• CMRR: > 80 dB (50 Hz to 5 kHz)
• Residual Noise (below +4 dBu output): <-85 dB (20 Hz to 20 kHz, 40 dB gain, 150 Ω source); <-70 dB (20 Hz to 20 kHz, 60 dB gain, 150 Ω source)
• Crosstalk: Below noise floor
• Indicators (3): POWER LED (blue), CLIP (2, red)
• Power Requirement: 24 Vdc @ 165 mA (190 mA with phantom), Ground-referenced
• Mounting: Rack-mount using optional rack adapters such as HR-RA2; or operate free-standing (feet included)
• Dimensions: Height: 1.7 in, 4.3 cm; Length: 8.6 in, 20.6 cm; Depth: 4.59 in, 11.66 cm