Palatine IL 60067
Products > Preamplifiers > MPX-4D

  Price: $2860.00

The Sytek MPX-4D Digitally-Controlled Four-Channel Microphone Preamplifier, finest in the world of professional audio.


With modern techniques, the MPX-4Aii's transformerless input design rivals and even surpasses the best transformer-input designs that were the standard in the industry earlier. This is especially true in low-level input applications to achieve extremely low noise floor, minimum distortion, wide bandwidth and linear phase response. This approach can be obtained a warm sound, crystal clear and fast response, getting a step closer to the human ear characteristics.

Each MPX-4D unit uses a Class A, auto-bias bridge configuration, hybrid input stage preamplifier based on hand-selected transistors for the lowest of noise, and the lowest possible base-spreading resistance and collaterally matched for perfect balance, and biased at the precise levels that make them maximally insensitive to thermal drift. As a result, no offset crowding occurs, and the dynamic range remains wide open. Because of the wide gain-bandwidth parameters of these specially-selected transistors, and the super-low impedance characteristics, and the vanishing circuit reactance, the impulse response is optimum, and phase-delay distortion undetectable. Gain adjustments are made with balanced differential-mode cancellation, preserving the excellent DC offset characteristics, without altering the loop feedback characteristics from their optimal configuration.

A need... no longer just a luxury: Digital Remote Control
It has become a 21st-century standard to have controls available from either the front panel or via a computer interface. The MPX-4D brings you just that. The quality of sound remains indistinguishable from our analog designed fixtures.


A premium quality gain control is followed by three rugged but nimble pushbutton controls for each of the MUTE, PHASE, and 48V (Phantom Power) functions.
The MUTE control allows the individual preamplifier section to be silently switched out of service.
The PHASE control allows the inversion of signal polarity.
The 48V control switches on phantom power, necessary when using condenser microphones.
Additionally, each preamplifier section has a Peak indicator, set at -8dB before clipping the signal output.

Digital control:
A high resolution optical encoder for changing the gain is displayed on a 1/4" dot matrix LED display calibrated in relative dB of gain for each of the four channels.

Burr-Brown op amps

The MPX-4Aii is available with Burr-Brown operational amplifiers in any or all channels. The Burr-Brown op amp is a high-quality amplifier that results in a warmer, tube-like response in contrast to the clean, ultra-fast response of our standard amp. We commonly ship a configuration with Burr-Brown op amps in channels 3 and 4.


Preamplifier topologyTransformerless Hybrid Design
Input Levelnominal -60 to -10 dBm
Gain+65 dB range (ref. input)
Maximum output24dBm loaded 600 ohms
E.I.Noise-134dBu (S.I.=50ohms) -129dBm(S.I.=150ohms)
THD+Noise0.0015 % at 60dB gain (@ 1kHz)
Signal-to-Noise Ratio> 100 dBm
Bandwidth10Hz-85 kHz +/- 0.25 dB
CMRR>100db at 100Hz
Phase Lin10 Hz - 20 kHz +/- 0.1 deg
Phantom P.S.+48V at 10ma (we can customize this for you)
I/O connectionsAuto-sense balanced/unbalanced XLR
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