Matrix Audio MP-1 Preamplifier

The MP-1 is Matrix Audio’s flagship preamplifier – the company’s first Class A design, and the middle piece of the M Series flagship system, sitting between the MS-1 music streamer and the MA-1 power amplifier. Its job is source selection and level control, done with as little interference to the signal as possible.

A Class A core, built without compromise

A fully differential transistor input stage feeds a high-bias Class A output stage, avoiding the crossover distortion a lower-bias design would introduce, and running from a 60V low-noise supply for extra dynamic range. An output DC servo circuit holds the midpoint offset to within 1mV, and there are no coupling capacitors in the signal path, for a flatter frequency response.

The main amplification section is built from four independent, fully balanced units, two per channel handling the in-phase and inverted signal separately; even an RCA input gets converted to a balanced signal internally, so common-mode noise is suppressed regardless of which input is in use.

Six inputs, individually matched

Three pairs of RCA inputs and three pairs of XLR inputs mean up to six sources can stay connected. Each input has its own adjustable level attenuation, so switching between sources doesn’t mean a jump or dip in volume from one to the next.

Two ways out, built for bi-amping

One pair of RCA outputs and two pairs of XLR outputs can run together or independently, with separate volume control on each when run independently. Using both XLR outputs together lets two power amplifiers each take one part of the signal, for a bi-amped setup driving a speaker’s mid-high and low-frequency sections separately.

Volume without compromise

Volume runs through a resistor-array voltage divider: four control units, each built from 64 precision resistors accurate to 0.001%, switched by 32 sealed reed relays under MCU control. The relays are close to silent even when the volume is changed continuously, and the design keeps the two channels closely matched across the full 100-step range. The included RM4C remote handles day-to-day control.

Power and build

Two 60W square-copper-wire toroidal transformers supply the volume control units and the main amplification section independently, left and right channel from the source. Square copper wire gives a larger conductor surface than the round wire in a conventional toroidal transformer, for higher current capacity and lower resistance. Mundorf’s M-Lytic AG filter capacitors round out the supply.

The chassis uses Matrix Audio’s H-shaped structure: a 20mm CNC-machined aluminium plate forms the core support, with the left and right channel circuitry in separate, isolated cavities on either side.

Specifications

In the box

• MP-1 preamplifier
• RM4C remote control
• Power cable
• Trigger cable
• User manual
• Warranty card

Downloads

• Matrix Audio MP-1 user manual