PROLOOP D5: class-D loop driver for supplying rooms of up to 300 m² with inductive audio signals

Highly reliable, resistant against short circuits and with great audio quality: The »PROLOOP D5« provides middle-sized rooms with stable inductive signals. Comfortable controls enable the user to take full benefit of the versatility this system offers regarding its use various rooms and deployment conditions.

The combo-XLR-3 in-port as well as a further phoenix contact are invidually configurable:
a) as audio-in (balanced)
b) as microphone-in (unbalanced)

A 12-V phantom power feed can be activated for the supply of condenser microphones.

The Automatic Gain Control (AGC) guarantees a constant field strength, a exemplary high stability in sound volume and good sound reproduction. A monitor port allows a dirct connection with further loop amplifiers.


  • Easy to use
  • High current output: 5,8 A RMS
  • Resistant housing
  • Compact build / requires lesser rack space
  • Low heat generation
  • Active protection against short circuits
  • Combo-XLR-3 input and
  • input via phoenix contact, configurable for:
    • microphone (phantom power)
    • audio source
  • Input for 100V-signals, transformer-decoupled
  • Automatic Gain Control (AGC), loop current control
  • 6,3mm headphone jack for monitoring audio signals
  • Adjuster for metal loss compensation
  • Suitable for setting up Low-Overspill-Systems
  • 19 inch rack mounting material included


Power supply: 90-265 V AC 50/60 Hz,
Passive protection: Fuse 3,15A T
Maximum area: 300 m² according to IEC 60118-4
###Loop output  
Max. current: 5,8 A RMS / 16,4 A peak-peak
Max. tension: 34 V RMS / 48 V peak-peak
---Active protection against short circuits  
Automatic Gain Control (AGC): Maintains a constant level of the audio signal
Frequency range: 100-5000 Hz ( ± 3 dB)
Distortion: < 1% at rated power output, 1 kHz
Connector: 1 Neutrik NL4 speakON-socket, layout 1+/1-
Headphones: Headphone output (on front face), jack plug socket 6,3 mm
---2x Slave Out with 0° and 90° phase shift, 6,3mm jack plug socket  
FAULT-output: Device status via potential-free switch contact, not earthed (NO / NC)
INPUT 1 and 2: 0,5 mV to 100 mV / 10 kOhm (MIC) or 25 mV to 4 V / 10 kOhm (LINE) phantom power configurable, Combo-XLR-3 socket (INPUT 1), Phoenix contact (INPUT 2)
---12V toggable phantom power  
INPUT 3: 100V-Input for connecting PA-systems
---Slave In, 6,3mm jack plug socket  
###Automatic Gain Control (AGC)  
Dynamics: up to 36dB
###Controls and indicators  
---Loop current adjustment via rotary control  
---Amplification control for INPUT 1, 2 und 3 via rotary control  
---Adjuster for the reduction of metal loss  
Indicators: Loop OK (LED, red)***Protect (LED, red)***Clip (LED, red)***ON / OFF (LED, blue)***AGC/Compression (2 green LEDs, 1 orange and 1 red LED)***Loop current (2 green LEDs, 1 orange and 1 red LED)
Size: 45 x 215 x 220 mm (H x B x T)
Mounting: 19 inch rack fixtures, included
Colour: black
Item no.: A-4280-0
Weight: 1,5 kg


A-4280-0, a42800, 4280