Description
The ST-VP1 is a dedicated voice-over and paging module designed to switch and blend a voice source with a music source. It provides user-controlled FADE or CUT transitions between two inputs to achieve consistent and repeatable fade levels. The unit is optimized for broadcast and installed-audio paging environments where low noise and predictable fades are required.
Key features include selectable fade-under or hard-cut switching, adjustable fade depth and rate, and soft audio switching for noiseless operation. The module supports a single adapted paging/voice input and a separate music input, each optimized for the intended source material. Operation can be manual or automated when integrated with compatible RDL ST-ACR controllers to enable automatic paging sequences.
Performance is engineered for clarity and low distortion, with music frequency response specified at 10 Hz to 20 kHz and voice response at 30 Hz to 20 kHz. THD+N for both inputs is below 0.01 percent and mute attenuation exceeds 65 dB for music and 80 dB for voice. Noise floor is specified at less than -85 dB relative to +4 dBu output and headroom exceeds 18 dB above +4 dBu.
Connectivity uses professional balanced +4 dBu input and output levels while permitting unbalanced connections where required. Gain is unity for either input when used with balanced signals, preserving downstream dynamics and level alignment. Fade rate is user adjustable across defined ranges and fade depth for the music input is adjustable from 3 dB to 40 dB to suit various program materials.
Typical applications include paging systems in retail or campus environments, voice-over announcements in production or playback facilities, and public address systems that require smooth transitions between background music and live speech. The ST-VP1 ensures announcements remain intelligible while maintaining musical ambience when required. Its controlled fade parameters enable consistent results across repeated announcements and operators.
Installation is straightforward and the module is engineered for reliable operation in ambient environments from 0 C to 55 C. It requires a ground-referenced 24 Vdc supply at 45 mA and ships in a compact cardboard package. The ST-VP1 combines precise fade control, low noise performance, and simple integration for professional paging and voice-over workflows.