Skip to product information
1 of 2



The ISA-280 Commercial Power Amplifier from QSC is a 3-RU rackmount power amplifier designed specifically for sound contractors. It can be used as a low-impedance solution rated for 2-Ohm operation at 430W per side, or 8-Ohm operation at 185W per side. The versatile loading options, feature set, and protection circuitry, in addition to the built-in HD-15 DataPort V2 DSP interface capability, ensures a high-value, cost-effective solution for budget-minded installations.

The ISA-280 is housed in a rugged all-metal chassis that features rear-panel gain controls for tamper-resistant operation and 2 dB detents for quick and repeatable settings. The inputs include both XLR and detachable Euro-style connectors, and the outputs feature covered barrier-strip connectors for full safety agency compliance.

More Information


  • Rear panel gain controls for tamper resistance; 2-dB detents allow for quick and repeatable settings.
  • XLR and detachable Euro-style input connectors
  • DataPort V2 for use with DPV2-compatible signal processing accessories (XC-3, SF-3, LF-3) and DSP-3/DSP-4 (with external power supply)
  • Independent defeatable clip limiters for reduced distortion
  • Selectable high-pass filters (30 Hz or 70 Hz) protect speakers and prevent speaker transformer saturation with minimal effect on program material
  • Front panel LED indicators include power, signal, and clip
  • Covered barrier strip output connectors for safety agency compliance
  • Automatic on-demand variable-speed fan: quiet normal operation, with maximum cooling when needed
  • Rear-to-front air flow helps keep equipment racks cool
  • Stereo, bridge, or parallel operating modes
  • Comprehensive protection circuitry including DC, infrasonic, thermal overload, and short circuit protection

Technical Specification

Tech Specs

  • Number of Channels:2
  • Power Class:Class AB
  • Watts/Side @ 8 ohms:185W
  • Watts/Side @ 4 ohms:280W
  • Watts/Side @ 2 ohms:430W
  • Watts Bridged:600W @ 8 ohm, 830W @ 4 ohm
  • 70V/100V Output:1500W
  • Inputs:2 x XLR, 2 x 3-pin Euroblock
  • Outputs:1 x Barrier Strip
  • Data I/O:DataPort V2 (DSP control)
  • Cooling System:Variable Speed Fan
  • Filters:Yes
  • Frequency Response:20Hz-20kHz
  • THD:<0.03%
  • Overload Protection:Full short circuit, open circuit, thermal, ultrasonic, RF
  • Rack Spaces:3U
  • Power Source:Standard IEC AC plug
  • Height:5.25"
  • Depth:15.9"
  • Width:19"
  • Weight:36 lbs.
View full details