QSC ISA450 2-Channel 260W Power Amplifier

Part of QSC's Installed System Amplifiers series, the ISA450 is a two-channel amp that drives 70-volt lines directly with 260 watts per channel. 

More about QSC’s ISA Power Amplifiers

Get professional power with Installed System Amplifiers. QSC’s ISA series is specifically designed to meet the high demands of sound system designers, contractors, and integrators around the world.

Sometimes called audio power amplifiers or power amps, power amplifiers increase the availability of electrical power to a specific source. Power amps are a versatile, yet crucial, piece of gear for anyone creating an audio setup, as they’re beneficial wherever you have a low-level signal that needs a boost. Examples of common power amp usage include entertainment and special events, home audio (theater, studio, office), instrumental performances, live concerts, portable PA, and other sound reinforcement applications.

Possibly the most common need for power amps is with passive loudspeakers: The mix-and-match nature of passive speakers and their components means that you can coordinate, scale, and personalize your audio equipment to your project’s needs—great for contractors and integrators who have specific audio parameters they’re aiming for, or for live sound setups that need to change or evolve!

Offering a variety of power amplifiers, QSC’s ISA series ensures you can find the right model that meets the specific configuration requirements of your setup. Three models feature isolated 25-, 70-, and 100-volt outputs for distributed sound systems, while four additional models boast low impedance and are rated for 2-ohm operation. Versatile loading options and a comprehensive set of features make the ISA Series a rugged, cost-effective solution for adding power to any permanently installed sound system.

QSC ISA450 Features

• 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

• ISA450 2-Channel 260W Power Amplifier1
• Three Year Warranty plus optional 3-year extended service contract1

• OUTPUT POWER PER CHANNEL, STEREO MODE, both channels driven
  • 8Ω, 20 Hz–20 kHz 0.1% THD: 260W
  • 4Ω, 20 Hz–20 kHz 0.1% THD: 425W
  • 2Ω 1 kHz 1% THD: 700W
• OUTPUT POWER, BRIDGED MONO MODE
  • 8Ω, 1 kHz 0.1% THD: 900W
  • 4Ω 1 kHz 1% THD: 1400W
• Signal to Noise (20 Hz-20 kHz)100dB
• Distortion (SMPTE-IM)Less than 0.01%
• Input Sensitivity @ 8 ohms1.07 V (+2.8 dBu)
• Maximum Voltage Gain44.7× (33 dB)
• Output CircuitryClass AB
• THX ApprovedYes
• Weight - Net36 lb (16.3 kg)
• Weight - Shipping42 lb (19.1 kg)
• Distortion (Typical) 20 Hz–20 kHz: 10 dB below rated powerLess than 0.03% THD, 4 ohms and 8 ohms
• 1.0 kHz and below: full rated powerLess than 0.03% THD, 4 ohms and 8 ohms
• Frequency Response 10 dB below rated output powerISA 280, 450, 750 and 1350: 20 Hz–20 kHz, +0/-1 dB; -3 dB points: 5 Hz and 50 kHz
• Damping Factor with 8Ω Load (direct outputs)Greater than 200; ISA 1350 greater than 250
• Output Regulation (isolated outputs)Less than 1.5 dB
• Input Impedance10 kΩ unbalanced, 20 kΩ balanced
• Input Clipping10 V rms (+22 dBu)
• CoolingContinuously variable speed fan, back-to-front air flow
• Connectors, each channel
  • Input: Active balanced; 3-pin Euro-style detachable terminal block and XLR (pin 2+)
  • Output: Covered barrier strips
  • DataPort V2: HD-15 connector
• Controls
  • Front: AC switch
  • Rear: Ch. 1 and Ch. 2 gain knobs, 10-position DIP switch
• Indicators
  • PWR-ON: Green LED; SIGNAL: Green LED (1 per channel);
  • CLIP: Red LED (1 per channel)
• Dimensions (HWD) inches5.25 x 19 x 15.9 / 3RU
• Dimensions (HWD) mm133 x 483 x 400 / 3RU
• Amplifier Protection
  • Full short circuit, open circuit, thermal, ultrasonic, and RF protection;
  • Stable into reactive or mismatched loads
• Power Requirements120 or 230 VAC, 50–60 Hz
• Load ProtectionOn/off muting; Triac crowbar: ISA 750, 1350, and 800Ti; AC coupling: ISA 280, 300Ti, 450, and 500Ti