The Adastra UM90 installation amplifier combines 100 V audio amplification with built-in USB playback, FM radio and a wireless Bluetooth receiver. Class D architecture and transformer output support operation on a 100 V line or with an 8 Ohm speaker load. The microphone, line and AUX inputs, as well as the USB, FM and Bluetooth sections, are controlled by the front-panel volume controls and master volume.

The mono line output and speaker outputs connect via screw terminals on the rear panel. There is also an alarm output with foghorn, siren and alert generators. Hardware is included for mounting two units side by side in a 1U 19" rack.

• Type: Integrated installation amplifier
• Output power at 100 V: 90 W
• RMS power at 24 V DC: 80 W
• Amplification technology: Class D with transformer output
• Audio sources: USB, FM and Bluetooth
• Inputs: 1 x 6.3 mm microphone, 1 x 2 RCA line and 1 x 3.5 mm AUX
• Line output: 2 x RCA, mono
• Speaker outputs: 100 V, 8 Ohms and common connection, with screw terminals
• Alarm output: Foghorn, siren and alert generators
• Power supply: 170–264 V AC, 50 Hz via IEC or 24 V DC
• Mute: 24 V relay contacts
• Harmonic distortion: < 0.4% at 1 kHz
• Input impedance: 1 kOhm for microphone and line
• Input sensitivity: -10 dB for line and -45 dB for microphone
• Signal-to-noise ratio: 80 dB for line and 75 dB for microphone
• Frequency response: 100 Hz–18 kHz
• Dimensions: 330 x 210 x 44 mm
• Weight: 3.02 kg