Description

The Digital MPA-II takes ART’s ProMPA-II design and adds built-in analog-to-digital conversion, so a single 2U rackspace unit handles preamp duty and digitizing in one pass. Each of the two channels runs on hand-selected 12AX7 tubes with switchable low or high plate voltage, giving you a range of tonal character from clean to more saturated. Variable input impedance (150 to 2400 Ohms) lets you tailor the load seen by dynamic and ribbon mics in particular, which can noticeably shift their tone and response.

Both channels include 48V phantom power and can run as dual mono or linked into stereo mode, with mid/side decoding built in for that miking technique. Metering is generous: large back-lit VU meters track output level while multi-color LED arrays show tube gain and digital levels with average or peak-hold readouts.

On the output side you get standard XLR and 1/4″ analog jacks alongside digital connectivity via S/PDIF, ADAT, or AES/EBU. A front-panel rotary control switches sample rates from 44.1 up to 192 kHz with 16-bit dithering, and two wordclock jacks with loop-through keep it synced in a larger digital rig.

Housed in a 2U steel rack chassis with a CNC-routed, black anodized aluminum face panel.

Discrete Class-A mic preamp, variable input impedance
Selectable plate voltage on dual 12AX7 tubes
Mid/side support, stereo or dual mono operation
Front-mounted instrument input with auto-selection
A/D conversion: 44.1 kHz to 192 kHz internal, 24/16-bit switchable dithering
ADAT, AES/EBU, S/PDIF digital outputs plus analog XLR/1/4″ outs
Two wordclock jacks with loop-through
Dynamic range >110dB (A-weighted), THD low, frequency response 15Hz-48kHz at normal plate voltage

This listing is for a demo unit.