Technical data
Frequency range	20 Hz - 20.000 Hz (-3dB)
Power consumption	12,6 W
Noise level	MIC: better than 65dB; LINE: better than 87dB
Total harmonic distortion	MIC: better than 0.1% at 1 kHz; LINE: 0.05% at 1 kHz
Height units	2 HE
Inputs	MIC/LINE 1-4: -50 dBu (2.45 mV), 5 kOhm, symmetrical; MIC/LINE 1-4: -10 dBu (245 mV), 15 kOhm, symmetrical; LINE 5-6: -10 dBu (245 mV), 15 kOhm, symmetrical; PAGING: -10 dBu (245 mV), 10 kOhm, symmetrical
Power supplies	230 V mains power (50/60 Hz) and 24 V DC (emergency power supply)
Dimensions (W x H x D)	483 x 88 x 260 mm; 2 HE
Outputs	REC OUT: 0 dBu (775 mV), 3 kOhm, unbalanced MONITOR: 0 dBu (775 mV), 200 Ohm, unbalanced
Crosstalk attenuation	MIC: 60dB, LINE: 70dB
19" rack mounting

The MXP-604 A from RCS Audio-Systems is a 4-channel mixing preamplifier with integrated 6-in-4 audio matrix, designed for flexible signal distribution in multi-zone sound systems. It enables routing of up to six input signals to four independent outputs, allowing different zones to be controlled individually. Particularly noteworthy is the compatibility with digital talk stations of type MXM-104 and VLM-100 A, which enable central control of announcements in selected zones.

Matrix Function and Inputs
The mixing preamplifier features a 6-in-4 matrix, allowing inputs to be flexibly routed to outputs. Inputs 1 to 4 are MIC/LINE combo inputs and can be switched between microphone and line input levels via a switch. These inputs feature a gain control, switchable phantom power, and have priority over inputs 5 and 6. Each input has its own volume, treble, and bass controls, a signal LED, and a zone selection switch. Inputs 5 and 6 are RCA line inputs and are also equipped with volume control, EQ, and zone selection. The paging input (Tel.-Paging) is connected via screw terminals and has the highest priority in the system, including the option to trigger a gong (2- or 4-tone) before the announcement.

Outputs and Monitoring
LED level indicators monitor the output signals, visually displaying the output level status. Additionally, a recording/monitor output is available, implemented via RCA and 6.3 mm jack socket. This output allows recording of a selected channel and includes a volume control and zone selection.

Technology Explained Simply
The frequency range of the MXP-604 A is 20 Hz to 20,000 Hz (–3 dB), enabling full reproduction of the human hearing range. The total harmonic distortion is better than 0.1 % at 1 kHz for microphone inputs and 0.05 % at 1 kHz for line inputs, indicating high signal purity. The noise level is better than 65 dB for microphone inputs and better than 87 dB for line inputs, indicating good signal-to-noise ratio quality. Crosstalk attenuation is 60 dB for MIC and 70 dB for LINE inputs, ensuring minimal signal interference between channels. The REC OUT and MONITOR outputs are unbalanced and deliver a signal of 0 dBu (775 mV) with an internal resistance of 3 kOhm and 200 Ohm, respectively.

Compatibility and Accessories
The MXP-604 A is compatible with digital talk stations MXM-104 and VLM-100 A, which connect to the device via dedicated connectors. The VLM-100 A talk station allows selection of zones for announcements and includes a volume control. The MXM-104 talk station enables remote control of four speaker circuits and also supports the all-call function. The connections for these talk stations are provided on the device, with the MXM-104 connecting via an optional receiver module RR-40.

Mounting and Installation
The mixing preamplifier is designed for 48,3 cm ( 19 inch ) rack mounting and occupies 2 height units (2 HE). Dimensions are 483 mm (width) × 88 mm (height) × 260 mm (depth). Power supply is either 230 V AC (50/60 Hz) or 24 V DC, enabling use in emergency power systems. Power consumption is 12.6 W. The rear of the device features connectors for inputs, outputs, power supply, and talk stations. Installation is in a standard 48,3 cm ( 19 inch ) rack, with power supply and signal cabling to be performed according to technical specifications.

Advantages in Operation
Operation of the MXP-604 A is particularly suitable for safety-critical applications, as it can be powered by mains voltage or 24 V DC (emergency power supply). The integrated 6-in-4 matrix enables flexible signal distribution, allowing different zones to be controlled independently. The ability to connect digital talk stations extends functionality and enables central control of announcements. LED level indicators and individual output settings ensure precise monitoring and control of the system. The combination of high noise level, low total harmonic distortion, and high crosstalk attenuation ensures high-quality signal transmission.