The Adastra UM Series is a range of ultra compact 100V mixer-amplifiers available in 30W, 60W, and 90W output variants, designed for small to medium public address installations where space is limited but a capable, self-contained unit is still needed.

Despite their compact footprint, each UM Series unit packs in a Class-D amplifier, an FM tuner, a Bluetooth 5.0 receiver with programmable ID, and a USB audio player — all controllable from the front panel via dedicated volume controls for the mic, line, and media player sections, plus an overall master volume.

The housing is sized so that two units can be mounted side by side in a single 1U 19" rack space using the supplied hardware, making the UM Series a practical choice for installations where rack space is at a premium or where two separate areas need amplification within a compact setup. It also accepts 24 Vdc power via rear screw terminals alongside standard mains input, supporting installations with backup power requirements.

• Ultra Compact Housing: Two units fit side by side in a single 1U rack space, saving valuable rack room in smaller installations or where multiple amplifiers are needed.
• Built-in FM, Bluetooth & USB: An integrated media player covers FM radio, Bluetooth 5.0 wireless streaming, and USB audio playback without requiring any external source equipment.
• Class-D Amplifier: Energy-efficient Class-D design with transformer output keeps the unit lightweight and cool-running, even in confined rack spaces.
• 100V or 8 Ohm Output: Switchable between 100V line and 8 Ohm operation via rear screw terminals, covering a range of speaker configurations.
• Flexible Inputs: A 6.3 mm mic jack, dual RCA line input, and 3.5 mm aux input cover the most common connection types needed in a small PA setup.
• 24V Mute Contacts: Rear-panel relay contacts allow the output to be muted via an external 24V signal, supporting integration with alarm or alert systems.
• Dual Power Supply: Accepts mains 170–264 Vac (IEC) or 24 Vdc via screw terminals, giving flexibility for installations with backup power.

Specifications

• Brand: Adastra
• Model: UM30 / UM60 / UM90
• Output Power (RMS): 30 W / 60 W / 90 W (variant dependent)
• Amplifier Class: Class D with transformer output
• Speaker Outputs: 100V / 8 Ohms / COM (screw terminals)
• Line Output: 2 × RCA (mono)
• Inputs: 1 × mic (6.3 mm jack), 1 × line (2 × RCA), 1 × aux (3.5 mm)
• Input Sensitivity: -10 dB (line) / -45 dB (mic)
• Input Impedance: 1k Ohms (mic/line)
• Audio Sources: FM tuner, USB player, Bluetooth 5.0 receiver
• Bluetooth Version: 5.0 (programmable ID)
• Frequency Response: 100 Hz – 18 kHz
• THD: <0.4% @ 1 kHz
• SNR: 80 dB (line) / 75 dB (mic)
• Mute: 24V relay contacts
• Mains Power Supply: 170–264 Vac, 50 Hz (IEC)
• DC Power: 24 Vdc (screw terminals)
• Rack Mounting: Two units side by side in 1U 19" rack (hardware supplied)
• Dimensions (W × H × D): 249.0 × 44.0 × 210.0 mm
• Weight: 2.35 kg (30W variant)

What You Get

• 1 x Amplifier
• 1 x Power Lead
• 1 x Rack Mounting Hardware