STM-2X

RDL STM-2X - Switched Microphone Preamplifier - 35 to 65 dB Gain

The RDL STM-2X is a compact microphone preamplifier with remote switching capability, designed for professional AV installations requiring precise microphone signal control. It supports quiet switching of condenser microphones and provides both mic-level and line-level outputs. Ideal for systems using push-to-talk buttons or toggle switches.

The unit offers adjustable gain from 35 to 65 dB (line output) and -15 to +15 dB (mic output), and supplies 24 V phantom power compliant with IEC 61938:2013. With low noise, high headroom, and excellent off-attenuation, the STM-2X ensures clean and reliable audio performance.

Functionality

• Microphone preamplifier with switchable mic or line output
• Remote control via push-to-talk or toggle switch
• Quiet soft-switching for condenser microphones
• Adjustable gain: 35-65 dB (line), -15 to +15 dB (mic)
• 24 V phantom power compliant with IEC 61938:2013
• Off-attenuation: >100 dB at 1 kHz
• Frequency response: 50 Hz - 30 kHz (±1.5 dB)
• Low THD+N: <0.05% at 50 dB gain
• Compact form factor for space-constrained installations

Features

• Device type: switched microphone preamplifier
• Input: 500 Ω balanced, 5 kΩ unbalanced
• Outputs: 1x line level (+4 dBu, 150 Ω), 1x mic level (-45 dBu, 150 Ω)
• Phantom power: 24V DC, filtered
• Power requirement: 24V DC / 10 mA
• CMRR: >50 dB (50 Hz - 20 kHz)
• Switching time: <5 ms
• Dimensions: 17 mm (H) x 76 mm (W) x 39 mm (D)
• Operating temperature: 0°C to 50°C

RDL STM-2X is a reliable solution for AV professionals needing flexible and quiet microphone switching with high-quality amplification.