Mixer Amplifiers

A mixer amplifier is a single unit that mixes microphones and music sources and amplifies the result to drive speakers directly. The Adastra UA Series 953.183UK, for example, has 3 switchable mic/line inputs, an RCA line input and a 3.5mm Aux input feeding a 30W amplifier with 100V line or 8 ohm output.

A power amplifier just amplifies a signal that has already been mixed, while a mixer amplifier has its own inputs, volume and tone controls, so microphones and music players plug straight in. A mixer amplifier suits a single room or a zoned shop or office; a separate mixer and power amplifiers suit larger systems that need more channels.

Yes, if many speakers share long cable runs, as in shops, schools and offices; where a few speakers sit close to the amplifier, low-impedance output is enough. Many Adastra models do either: the UM Series 953.176UK switches between 100V line and 8 ohms, and the RM-series 953.225UK has 100V outputs plus an optional 4-16 ohm output.

Yes, on models with a Bluetooth receiver. The Adastra DM-Series 953.109UK pairs with a smartphone or tablet for wireless playback, and the MM240 953.030UK and RM-series 953.225UK receivers have a unique serial ID, which helps tell units apart where several are installed. The UM Series 953.179UK has Bluetooth with a programmable ID.

Use a zoned mixer amplifier. The Adastra V-series 953.251UK feeds two independent zones, with a rotary selector per zone to choose its source, and the A14 953.414UK has two independent audio players for two zones. The RM406 953.160UK covers six zones from its 6 x 40W class D section, for multi-room systems.

Through a priority or VOX function on the microphone channel, which turns the music down when someone speaks. The TOA A-2120D attenuates the other inputs under MIC-1 priority, the Adastra RM406 953.160UK has variable mic priority with a chime function, and the UX Series 953.014UK has an optional Vox priority function on its microphone input.

Yes, where it has emergency mute contacts. The Adastra UA Series 953.183UK and 953.189UK have 24V fire alarm mute contacts, the RM-series 953.227UK has 24V emergency mute contacts, and the 953.244UK has an emergency evacuation connection through fire alarm panel contacts, so the music stops when the alarm sounds.

Yes, on a channel with phantom power. The Adastra MM240 953.030UK, 953.163UK and RM406 953.160UK have switchable +20V phantom power, and the TOA A-2240D supplies +21 V on MIC1 for condenser microphones. Dynamic microphones do not need phantom power, so leave it switched off for them.

Yes, many can. The Adastra RM-series 953.225UK is 19in rack-mountable, the UM Series 953.176UK is supplied with hardware to mount two units side by side in a 1U 19in rack space, and the UA Series 953.189UK has rack hardware that can also fix a single unit against a wall or under a worktop.