Fosi Audio ZA3 Balanced Stereo Amplifier

The Fosi Audio ZA3 Balanced Stereo Amplifier gives compact audio systems a flexible power center for passive speakers, powered subwoofer integration, and balanced source connections. Its dual mode design lets the amplifier work as a stereo amplifier for a two-channel setup or as a mono amplifier when paired into a scalable left and right configuration.

Balanced Input Flexibility

ZA3 supports RCA, XLR, and 1/4 inch TRS input options, giving listeners multiple ways to connect DACs, preamps, streamers, and other line-level audio sources. The balanced input path is useful for systems where lower interference and cleaner signal routing matter, especially on desks, shelves, and compact component racks.

Power for Stereo or Mono Systems

With a Texas Instruments TPA3255 Class D amplifier chip, the ZA3 supports 2 to 8 speakers and rated output up to 155W x2 at 4 with a 48V/5A power supply in stereo mode. In mono mode, it delivers rated output up to 235W x1 at 4, letting users pair two ZA3 amplifiers for a dedicated left and right speaker setup.

Subwoofer Output and System Control

An active subwoofer output makes it easier to build a 2.1 channel listening system with passive speakers and a powered subwoofer. The 12V trigger input allows synchronized power control with compatible devices, reducing the need to turn each component on or off separately.

The aluminum alloy chassis, side ventilation, dust covers, and whole-body heatsink support stable operation in compact spaces. Swappable DIP8 dual op amp support also gives advanced users room to tune the amplifier to their preferred sound profile.