; 8th Street Music - QSC RMX 850
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300w Per Channel @ 4ohms Power Amplifier

Product Code 1703

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The RMX Series amplifiers give you clean, dynamic power with the legendary QSC sound quality and reliability that pros depend on. The RMX Series deliver unmatched performance at a new breakthrough price.

Muscular Power Plant
The power supply is the heart of an amplifier, converting raw AC power from the wall to clean DC for the audio circuitry. The RMX uses a powerful high-current toroidal transformer and ample filter capacitance to ensure generous energy reserves. This makes a critical difference in sound quality, allowing the amp to effortlessly punch out high-level transients, even when driving abusive 2-ohm speaker loads.

Superior Performance
RMX amplifiers deliver true studio-quality sound. A full, complementary output circuit using the highest-grade linear output devices delivers ultra-low distortion (<0.05% THD) and a ruler-flat frequency response. SMT (Surface Mount Technology) triples small-signal component density, enabling us to pack up to 2400 watts of power in a chassis only 2 rack spaces and less than 16 in. deep. And, unlike other designs, RMX output devices are direct-mounted to the heat sink for optimum thermal coupling and cooling.

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The RMX Series is packed full of professional features that increase performance and flexibility:

Independent defeatable clip limiters reduce distortion without sacrificing peak performance.

Selectable low-frequency filters boost system response, protect speakers, and ensure low-end tightness by more precisely matching the amplifier's range to the loudspeakers.

Barrier strip, XLR, and 1/4 in. balanced inputs plus Speakon and binding post outputs provide easy connections.

Low-noise variable speed fans with rear-to-front air flow keep amplifiers and racks cool.

Proven Reliability
With over 30 years of building amplifiers for the largest touring companies and venues around the world, you can count on QSC's reputation for designing the most reliable amps available.

Technical Description

Stereo Mode
(EIA: both channels driven)
8 ohms EIA 1 kHz 0.1% THD: 200W
4 ohms EIA 1 kHz 0.1% THD: 300W
2 ohms EIA 1 kHz 1% THD: 430W

Bridge Mono Mode
8 ohms EIA 1 kHz 0.1% THD: 600W
4 ohms EIA 1 kHz 1% THD: 830W

Signal to Noise (20 Hz-20 kHz): 100 dB
Distortion (SMPTE-IM): Less than 0.01%
Input Sensitivity @ 8 ohms: 1.15v (+3.4 dBu)
Voltage Gain: 31.6x (30 dB)
Output Circuitry: AB
Current Consumption (1/8 power pink noise at 4 ohms @ 120VAC,
both channels driven; multiply current by .5 for 230V units.): 5A
Weight (Net): 35 lbs. (15.9 kg)
Distortion (typical):
20 Hz-20 kHz: 10 dB below rated power: Less than 0.03% THD 4 and 8 ohms
1.0 kHz and below: full rated power: Less than 0.03% THD 4 and 8 ohms
Frequency Response:
20 Hz-20 kHz, ± 0/-1 dB, -3 dB points: 5 Hz-50 kHz
Damping Factor (1 kHz and below): Greater than 300 at 8 ohms
Input Impedance: 10 K ohms unbalanced, 20 K ohms balanced
Input Clipping: 10 Vrms (+22dBu)
Cooling: Continuously variable speed fan, rear-to-front air flow

Connectors (each channel):
Input: Active balanced; barrier strip, XLR, and 1/4 in. (6.3 mm)
TRS tip and XLR pin 2 positive
Output: "Touch-proof" binding posts and Neutrik Speakon
Front: AC switch, Ch. 1, and Ch. 2 gain knobs
Rear: 10-position DIP switch
PWR-ON: Green LED SIGNAL: Yellow LED (1 per channel)
CLIP: Red LED (1 per channel)
Amplifier Protection: Full short circuit, open circuit, thermal, ultrasonic, and RF protection. Stable into reactive or mismatched loads.

Load Protection: Turn-on/off muting, AC coupling (850, 1450), triac crowbar (2450, on each channel)

19 in. (48.3 cm) rack mounting, 3.5 in. (8.9 cm) tall (2 rack spaces),
15.9 in. (40 cm) deep (rack mounting to rear support ears)
Power Requirements: 100, 120, 230 VAC, 50-60 Hz

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