The DSPPA DA4125 is a four-channel Class-D power amplifier delivering 120W per channel on 70V or 100V lines, built into a 1U rack chassis. It suits schools, mosques and offices that need four separately controlled sound zones.
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The DSPPA DA4125 is a four-channel Class-D power amplifier rated at 120W per channel, with 70V and 100V speaker outputs. It fits a single 1U slot in a 19-inch rack. Schools, mid-size mosques and offices use it to split a building into four independent zones, each with its own speakers and its own level.
DSPPA DA4125 key specifications
Total output is 480W across four channels. Every channel has a dedicated volume knob on the front panel, so the courtyard can run loud while the admin wing stays quiet.
- 4 x 120W channels on a 70V or 100V line.
- Frequency response: 80Hz to 15kHz (±3dB).
- THD below 0.3% at 1kHz; signal-to-noise ratio above 80dB.
- Channel separation above 70dB, so one zone does not bleed into the next.
- Input sensitivity: 775mV on the balanced inputs.
Priority inputs for bells and paging
Next to the standard balanced line input, the rear panel carries a balanced priority input and a 100V priority input. When a priority signal crosses its threshold, the amp mutes the normal input and passes the announcement. Music returns 2 to 3 seconds after the page ends. A balanced line output lets you feed a second amplifier over a longer cable run with less noise if the system grows.
Mains or 24V battery power
The DA4125 runs on 180 to 250V AC and also accepts a 24V DC feed from a backup battery system, with rated output reduced by 3dB on DC. Power draw is 653W at 220V AC and 398.4W at 24V DC; idle draw is 63.5W. Active PFC, a switch-mode power supply and a temperature-controlled fan keep it efficient inside a closed rack.
Protection and status LEDs
Protection covers power-on, over-temperature, DC on the output and short circuits on the speaker line, backed by a voltage limiter. Five front LEDs show protect, limit, signal, clip and 70V mode, so a technician can read every channel at a glance.
Typical projects in Saudi Arabia
- Schools: one channel each for classrooms, courtyard, admin and sports hall, with the morning broadcast and class bell on the priority input.
- Mosques: main prayer hall, women's section and outdoor horn speakers on separate channels.
- Offices and clinics: background music in reception and corridors, plus paging that reaches every department.
- Lecture and training rooms: one channel per room, so each trainer sets a level without affecting the others.
Pairing with speakers and a mixer
A 70V/100V line lets you hang many speakers on one cable. Keep the total of the speaker taps on each channel below 120W; ten ceiling speakers tapped at 10W, for example, add up to 100W and leave headroom. The inputs are line level only, so add a preamp or mixer such as the DSPPA MP9811P for microphones and music sources.
DA4125 or DA4250?
Both models share the same 1U chassis, inputs and 7kg net weight. The difference is power and draw: the DA4250 delivers 250W per channel (1000W total) and pulls 1240W from the mains, while the DA4125 delivers 120W per channel (480W) and pulls 653W. Pick the DA4250 when a zone needs more than 120W of speakers. If every zone stays under 60W, the 4 x 60W DA4060 is enough.
Frequently Asked Questions
Does the DA4125 have microphone inputs?
The official datasheet lists line-level inputs only (balanced and priority). Connect microphones through a preamp or mixer such as the DSPPA MP9811P.
How many speakers can one channel drive?
It depends on the tap setting. Keep the total below 120W per channel, for example ten ceiling speakers at 10W or three horn speakers at 30W.
Will it run from batteries during a power cut?
Yes. It accepts a 24V DC supply; rated output drops by 3dB and power draw is 398.4W on DC, per the datasheet.
Specifications
- Model: DA4125
- Series: DSPPA DA Class-D series (DA2125 / DA2250 / DA2500 / DA4060 / DA4125 / DA4250)
- Type: Class-D digital power amplifier
- Channels: 4
- Rated output per channel: 120W
- Total rated output: 480W (4 × 120W)
- Speaker output: 70V / 100V with real-time selector switch
- Input sensitivity: 775 mVRMS (0 dBV, all balanced inputs); 100 VRMS (100V unbalanced input)
- Signal-to-noise ratio: Above 80 dB (at 100 VRMS output)
- Input impedance: 60 kΩ (balanced); 20 kΩ (balanced priority); 100 kΩ (100V unbalanced)
- Channel separation: Above 70 dB (1 kHz)
- Frequency response: 80 Hz to 15 kHz (±3 dB, normal operation)
- THD: Below 0.3% (1 kHz, normal operation)
- Slew rate: Above 29 V/µs
- Priority threshold: Above 10 mVp (balanced priority input); above 1000 mVp (100 VRMS priority input)
- Rear inputs and outputs: Balanced line input (3-pin HT-3.81), balanced priority input (3-pin HT-3.81), 100 VRMS unbalanced priority input (2-pin HT-3.81), balanced line output (3-pin HT-3.81), 70V/100V speaker output on covered 7.62-4P socket
- Priority behaviour: A priority signal above threshold mutes the normal balanced input, which returns 2 to 3 s after the signal drops below threshold
- Front panel: Volume knob per channel, power switch with indicator, 5-unit LED status display
- Indicators: PRO, LIM, voltage limit, SIG, 70V gear
- Protection: Power-on, high temperature, DC, short circuit, plus voltage-limit circuit
- Amplifier stage and PSU: Class-D stage with switch-mode power supply and active PFC
- Cooling: Temperature-controlled fan speed, rear air outlet
- Power supply: AC 180-250V, 50/60 Hz; DC 24V (rated output -3 dB)
- Power consumption: 653W (AC 220V); 398.4W (DC 24V)
- Static power consumption: 63.5W (AC 220V); 62.4W (DC 24V)
- Chassis dimensions (excl. feet): 483 × 435 × 44 mm (1U)
- Feet: 4 removable soft plastic feet, 6.5 mm
- Net weight: 7 kg
- Mounting: 19-inch rack, 1U, or flat surface
Features
- 4 channels x 120W: split a building into four zones, each with its own front-panel volume knob.
- 70V/100V output with selector switch: run many speakers on one cable over long distances.
- Two priority inputs (balanced and 100V) with 2 to 3 s auto-return: bells and pages cut in, then music comes back on its own.
- 24V DC input alongside 180-250V AC: keep announcements running from backup batteries during a power cut.
- 1U chassis, 44mm high: takes a single slot in a 19-inch rack.