The DSPPA DMA250U is a 250W digital mixer amplifier and the most powerful DMA60U-series model that keeps both 70V and 100V outputs. Two chimes, a siren trigger and an EMC input sit alongside USB, Bluetooth and FM, which makes it a natural fit for school PA, offices and larger restaurants.
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The DSPPA DMA250U packs 250W into an 88 mm tall chassis with 70V, 100V and 4-16 ohm outputs. That makes it the most powerful DMA60U-series model to keep a 70V tap, so a school or office with older 70V speakers can upgrade the amplifier without rewiring. DSPPA also gave it the chime, siren and emergency tools that school PA systems rely on.
DSPPA DMA250U for school announcements
A school day has morning assembly, announcements between lessons and the occasional urgent alert. The DMA250U handles all three:
- Chime 1 and Chime 2 on the front panel, adjustable from level 0 to 15, to get students' attention first.
- A SIREN input triggered by a short circuit from a remote button or another panel, with a separate alarm output.
- An EMC input at 350mV sensitivity that accepts a pre-recorded message from another device.
- A MUTE input for silencing the system remotely.
Who gets heard first
DSPPA sets the priority as MUTE, then EMC, alarm and chime at equal level, then MIC1, then all other inputs. When the deputy head speaks into MIC1, music or radio drops back. An emergency message overrides even the microphone, and chimes are suppressed during an alarm so tones never overlap.
Inputs and sources
MIC1 is on the front; MIC2 and MIC3 are balanced on the rear with switchable 48V phantom power, and MIC3 can be flipped to AUX2 with a selector. Add AUX1, an AUX OUT and built-in Bluetooth, USB and FM, and you can play the national anthem, a recitation or any track from a phone. Each source has its own volume, plus bass and treble at ±10dB. A segment display shows the active source, and power-off memory keeps your settings after an outage.
Power and backup
The rear panel has an AC voltage selector and a DC 24V input labelled 18A for a backup DC supply. It operates from -10 to 50°C at 20-80% humidity and measures 430 x 330 x 88 mm.
Where the DMA250U fits in Saudi Arabia
- Primary and intermediate schools: classroom, corridor and yard speakers on a 100V or 70V line.
- Offices and government departments: staff paging and reception music.
- Large restaurants and small event halls: phone playback with a mic for announcements.
- Mid-size warehouses: paging over horn speakers with a siren alert.
DMA250U, DMA120U or DMA350U?
The DMA120U offers 120W with the same inputs and 70V/100V outputs in a 280 mm wide, 4.6 kg box, right for a shop or clinic. The DMA250U roughly doubles that to 250W and adds an AC voltage selector. The DMA350U steps up to 350W with an output-mode switch, but drops the 70V tap and offers 4-16 ohm and 100V only. Choose the DMA250U when your speakers total between 120W and 250W, or when you need to keep a 70V line.
Frequently Asked Questions
Is the DMA250U suitable for school PA?
Yes. It has two chimes, a siren trigger and an EMC input, plus USB, Bluetooth, FM and 70V/100V outputs for classrooms and the yard.
Will it drive 70V speakers?
Yes. The DMA250U offers 70V, 100V and 4-16 ohm outputs and is the most powerful model in the series that keeps a 70V tap.
Can it run from a 24V supply?
There is a DC 24V input labelled 18A for a backup supply. The DC output is not published for this model, so confirm it before designing a backup system.
Specifications
- Model: DMA250U
- Series: DMA60U Series (DMA60U to DMA650U)
- Rated output (AC): 250W
- Speaker output: 4-16Ω, 70V, 100V (constant voltage)
- Microphone inputs: MIC1 front, MIC2 and MIC3 balanced on rear
- AUX inputs: 2 (AUX2 shared with MIC3 via selector switch)
- Emergency input: 1× EMC input
- Line output: 1× AUX OUT
- Phantom power: +48V for MIC2/MIC3, rear switch
- MIC1 / MIC2 sensitivity: 10mV ±1mV
- AUX1 / AUX2 / EMC sensitivity: 350mV ±50mV
- MIC frequency response: 120Hz-12kHz (±3dB)
- AUX frequency response: 80Hz-15kHz (±3dB)
- THD: <1%
- SNR (A-weighted): AUX ≥75dB, MIC ≥71dB
- Tone controls: Bass and treble ±10dB (±2)
- Built-in sources: USB, Bluetooth, FM radio (with FM antenna socket)
- Chimes and alarms: Chime 1 and Chime 2 (level 0-15), SIREN short-circuit trigger with alarm output, MUTE short-circuit trigger
- Priority: MUTE > EMC = Alarm = Chime > MIC1 > others (no chime during alarm)
- Control and display: Segment display, IR remote control, power-off memory
- AC power supply: 50/60Hz, with AC voltage selector
- DC input (rear-panel label): 24V / 18A
- Rear-panel switches: AC voltage selector, phantom switch, AUX2/MIC3 selector, MIC gain, alarm gain
- Operating temperature: -10 to 50°C
- Relative humidity: 20% to 80%
- Dimensions (D × W × H): 430 × 330 × 88 mm
Features
- 250W with 4-16 ohm, 70V and 100V outputs: covers classrooms, corridors and the yard on one line and works with existing 70V speakers.
- Chime 1 and Chime 2, level 0-15: an attention tone before announcements or the morning assembly.
- SIREN short-circuit trigger with alarm output: fire the siren from a remote button or another panel, ahead of mic and music.
- EMC emergency input at 350mV: takes a message from another device and overrides everything except MUTE.
- AC voltage selector and an 18A DC 24V input: run on mains or from a 24V backup supply.