The Adastra A4 installation amplifier provides independent stereo playback in two output zones and incorporates a mixer for two microphones and stereo audio sources. The built-in media player supports MP3 files from USB or an SD card, and FM and Bluetooth receivers are also included.

Each zone selects a source from the two stereo inputs, the front 3.5 mm input, or the media player. The microphone inputs can transmit audio to both zones, while the speaker outputs use 4 mm terminals. Protection includes thermal, overcurrent, overvoltage, and short-circuit protection.

• Type: Integrated installation amplifier
• Channels: 4
• Output zones: 2 independent stereo zones
• Amplifier technology: Class D
• Output power at 4 Ω: 4 × 200 W
• Output power at 8 Ω: 4 × 100 W
• Frequency response: 20 Hz–20 kHz ±0.5 dB
• Dynamic range: 92 dB
• THD+N distortion: <0.1%
• Microphone inputs: 2 mono 6.3 mm jacks
• Line inputs: Line 1 L+R (6.3 mm/RCA), Line 2 L+R (RCA)
• Line input sensitivity: 0.775 Vrms
• Auxiliary input: 3.5 mm stereo jack
• Auxiliary input sensitivity: 0.480 Vrms
• Input impedance: 20 kΩ (balanced), 10 kΩ (unbalanced)
• Audio sources: USB, SD card, FM receiver, Bluetooth receiver
• Bluetooth version: 2.3
• Line output: 4 RCA
• Speaker outputs: 4 mm terminals, 4 channels
• Antenna connection: F-type for the FM receiver
• Input controls: Aux, Media, Line1, Line2, Mic1, Mic2, Talkover
• Output controls: Source selection × 2, Bass × 2, Treble × 2, Ch1, Ch2, Ch3, Ch4
• Protection: Thermal, overcurrent, overvoltage, and short-circuit
• Power supply: 230 V AC, 50 Hz (IEC)
• Fuse: F5A, 250 V
• Width: 482 mm
• Height: 88 mm
• Depth: 240 mm
• Weight: 5.98 kg