The PS Engineering PMA4000 is a compact panel-mounted audio selector and 4-place intercom system designed for general aviation aircraft. It combines audio switching, intercom functions, and a built-in speaker amplifier in a single unit.

It allows switching between two COM transceivers and two NAV receivers, and includes multiple unswitched audio inputs for alerts such as GPS, autopilot disconnect, or warning systems. The integrated IntelliVox® voice-activated intercom system automatically handles squelch without manual adjustment, improving clarity and reducing cockpit noise interference.

The unit supports multiple intercom modes (ISO, ALL, OFF), enabling either pilot isolation or full cockpit communication. It also includes automatic fail-safe audio routing so that in the event of power loss, the pilot remains connected directly to the aircraft radio system.

Designed for small panel footprint installations, it is commonly used in light aircraft and experimental aircraft where space-saving integrated audio management is required.

Key features include:

PS Engineering part number: PMA4000 (P/N 11942)
Panel-mounted audio selector + 4-place intercom
Supports 2 COM and 2 NAV audio sources
Built-in speaker amplifier
IntelliVox® automatic voice-activated intercom
ISO / ALL / OFF intercom modes
Fail-safe direct pilot-to-radio connection on power loss
Multiple unswitched audio inputs (alerts, GPS, autopilot)
Compact form factor for small instrument panels
FAA TSO-C50c approved audio system