QSC ISA 750 2-Channel Power Amplifier, 650W at 4 Ohms

Designed as a cost-effective solution specifically for sound contractors, QSC's ISA Series features seven models including four low impedance models (ISA 280, ISA 450, ISA 750, ISA 1350) rated for 2 Ω operation, and three "Ti" versions with isolated 25, 70 and 100 volt outputs for distributed audio systems (ISA 300Ti, ISA 500Ti, ISA 800Ti). Versatile loading options and a comprehensive feature set make the ISA Series a rugged, cost-effective power solution for any permanently installed sound system.

Housed in a rugged 3U chassis, the ISA750 features rear panel gain controls for tamper resistant operation with 2 dB detents for quick and repeatable settings. Inputs include both XLR and detachable Euro-style connectors. Outputs feature covered barrier strip connectors for safety agency compliance, and for added versatility, a DataPort V2 terminated with an HD-15 connector is provided for use with DPV2-compatible signal processing accessories. Plus, selectable high-pass filters are included to protect speakers and prevent speaker transformer saturation with minimal effect on program material.

The ISA 750 also offers class H complementary bipolar output circuitry to increase system efficiency by reducing AC power draw and waste heat by 40%. Cooling is accomplished via an automatic variable speed fan, which pulls air from back to front.

Features

• Rear panel gain controls for tamper resistant operation with 2 dB detents 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 protect speakers and prevent speaker transformer saturation with minimal effect on program material
• Front panel indicators include power, signal and clip
• Stereo, Bridge, or Parallel operating modes
• Comprehensive protection circuitry including DC, infrasonic, thermal overload and short circuit protection
• 3-year warranty plus optional 3-year extended service contract

Specifications

• 8 Ohms 20 Hz - 20 kHz, 0.1% THD: 450W
• 4 Ohms 20 Hz - 20 kHz, 0.1% THD: 650W
• 2 Ohms 1 kHz, 1% THD: 1200W
• Bridged Mono 8 Ohms 1 kHz, 0.1% THD: 1500W
• Bridged Mono 4 Ohms 1 kHz, 1% THD: 2400W
• 140V or 200V 50 Hz - 16 kHz, 0.5% THD: 1600W
• Signal to Noise (20 Hz - 20 kHz): 100 dB
• Distortion (SMPTE-IM): < 0.02%
• Input Sensitivity @ 8 Ohms: 1.07v (+2.8 dBu)
• Voltage Gain @ 8 Ohms: 56.2x (35 dB)
• Output Circuitry: Class H
• Distortion (Typical):
  • 20 Hz-20 kHz: 10 dB below rated power: Less than 0.03% THD, 4 Ohms and 8 Ohms
  • 1.0 kHz and below: full rated power: Less than 0.03% THD, 4 Ohms and 8 Ohms
• Frequency Response, 10dB below rated output power: 20 Hz - 20 kHz, +0/-1dB, -3dB points: 5 Hz + 50 Hz
• Damping Factor (Direct Outputs): > 250 @ 8 Ohms
• Output Regulation: < 1.5 dB
• Input Impedance: 10 kOhms unbalanced, 20 kOhms balanced
• Input Clipping: 10 Vrms (+22 dBu)
• Cooling: Continuously variable speed fan, back-to-front air flow
• Connectors, each channel:
  • Input: Active balanced; 3-pin Euro-style detachable terminal block and XLR (pin2+)
  • 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 RedLED (1 per channel)
• Amplifier Protection: Full short circuit, open circuit, thermal, ultrasonic, and RF protection; Stable into reactive or mismatched loads
• Power Requirements: 120, 230, VAC, 50-60 Hz
• Load Protection: On/off muting; Triac crowbar: ISA 750
• Rack-mount size: 3 RU
• Dimensions: 19" x 5.25" x 15.9" (48.3 x 13.3 x 40 cm)
• Weight: 47 lbs. (21.3 kg)