Overview

The Tube MP/C (PreAmplifier/Compressor) is a multi-purpose tool for audio engineering and recording. Two independent circuits featuring a tube-based analog preamplifier and a VCA-less compressor with optical gain reduction control are housed in one, convenient desk-top chassis.

Used as a mic/line preamp or as a DI (direct) box, the Tube MP/C is designed to work seamlessly with any recording, sound-reinforcement, or electronic instrument setup. A R T’s Tube MP/C circuitry is a hybrid design utilizing the latest, most advanced, solid-state and tube technology.

The preamplifier’s active balanced solid-state input provides extremely low noise and excellent common mode rejection. The ¼-inch high impedance input prevents loading of any connected device making the Tube MP/C perfect for DI or line level applications. The preamplifier’s second stage 12AX7a tube runs on a regulated DC voltage providing an additional 20dB of gain.

The compression circuit features a VCA-less design and utilizes optical electronics (Vactrol) coupled with a 12AX7a vacuum tube gain stage for superior musical performance.

Optional ART SM1 stand mount securely attaches the Tube MP/C to any microphone stand for live stage or studio applications is available.

Key Features

• Tube-based mic/line preamplifier with up to 80 dB of gain
• Hand-selected 12AX7a tube
• Optical (VCA-less) compressor circuitry = transparent dynamics control
• 1/4-inch unbalanced inputs and outputs
• XLR balanced inputs and outputs
• Transformer isolated XLR output
• Selectable output range for Line/Instrument interface levels
• LED meters for Tube Warmth, Gain Reduction and Output level
• +48V phantom power
• Phase reversal switch
• Selectable release time settings
• > 90dB dynamic range
• Custom extruded aluminum chassis

Specifications

• Frequency Response: 30 Hz – 60 kHz +/- 1 dB balanced output, 20 Hz – 60 kHz +/- 1dB 1/4″ output
• Total Harmonic Distortion: <0.1% @ max gain
• CMMR: > 60 dB @ max gain
• Equivalent Input Noise: -128dBu typical (“A” wtd., Shorted XLR balanced input, gain @ max)
• Input Impedance: 1M Ω 1/4″ input, 5K Ω XLR input
• Input/Output Connections: Input: XLR balanced or 1/4″ balanced. Output: 1/4″ unbalanced XLR balanced, transformer isolated.
• Maximum Gain: +80 dB (balanced in-out, +64dB (unbalanced input, balanced output)
• Maximum Input Level: unbalanced (Inst): +15 dBu, balancd (mic): +10 dBu
• Maximum Output Level: +19 dBu (Line mode)
• Output Impedance: XLR: <600 Ω, 1/4″: <300 Ω
• Low Cut Filter: -3 dB @ 70 Hz, 6dB/Octave
• Phantom Power: Switch selectable, +48Volts DC, filtered, current limited
• Chassis Type: All aluminum black anodized with integral rubber sides
• Power Requirements: 9VAC @ 1000mA (external)
• Attack Time: <1 ms (limit), 20 ms (comp.)
• Release Time: 150ms (fast), 20ms – 3s Program dependant (Auto)
• Tube Type: Hand selected 12AX7a
• Compressor Slope: 2:1 (Comp.) / 11:1 (Limit)
• Dimensions: 1.75″H x 5.9″ W x 6.5″ D (44.5mm x 150mm x 165mm)
• Weight: 2.9 lbs (1.32 kg)
• Notes: 0dBu = 0.775V rms
• Weight includes power supply and packaging