Specifications
COMMERCIAL AUDIO
• 25
T
he Crown
®
660A is a very flexible, high-value six-channel amplifier for commercial and industrial
audio. It provides 4-ohm and constant-voltage outputs (70V and 100V) on channels 1 through 4,
and 4-ohm outputs on channels 5 and 6. The 660A is a part of Crown’s Commercial Audio Series, which
also includes mixers and mixer-amps. These low-cost units provide all necessary features in a simple
building-block format.
SPECIFICATIONS
Performance
Frequency Response (at 1 watt from 4-ohm tap):
70 Hz to 19 kHz ±1 dB.
Frequency Response (at line out): 20 Hz to 20 kHz
+/- 1 dB.
Power Bandwidth (at 4-ohm tap, 2 dB below
maximum 1 kHz power): 50 Hz to 20 kHz with
< 0.5% THD
Signal to Noise Ratio (ref. to rated power, master
volume at minimum): 85 dB.
DC Output Offset: < ±5 mV.
THD: Less than 0.5% at rated power at 1 kHz.
Input Sensitivity (for full output at maximum
gain): 800 mV.
Input Impedance (nominal): 100 kilohms.
Crosstalk (all controls at “10”): –70 dB at 1kHz.
Line Output Level (nominal): 1V into 10 kilohms.
AC Line Voltage and Frequency Configurations
Available:
100V 50/60 Hz.
120V 60 Hz.
220V 50/60 Hz.
230V 50/60 Hz.
240V 50/60 Hz.
Operating Temperature/Humidity: 0° C to 40° C
at 95% relative humidity (non-condensing).
Storage Temperature: –20° C to 85° C.
Front Panel Controls and Indicators
Power Switch: Push-button on-off switch. The
power switch does not affect the 24V DC auxiliary
power input.
Power Indicator: Blue LED indicates power on.
Output Signal Presence Indicator: Green LED,
one for each output channel, illuminates when out-
put signal level exceeds 100 mV (45 dB below full
power) from the 4-ohm tap.
Clip Indicators: Red LED, one per output channel.
Illuminates at threshold of audible distortion.
Master Volume Controls: One per output channel.
Detented potentiometer with knob.
Tone Controls: Bass and Treble non-detented
potentiometers on each channel. Bass ±10 dB at
100 Hz, Treble ±10 dB at 10 kHz.
Back Panel Controls and Connectors
Reset Switch: Resets the circuit breaker that pro-
tects the power supply. 220/230/240V units have a
fuse instead.
AC Power Inlet: Detachable IEC.
Amplifier Outputs Connectors: One per channel,
4-position terminal strip with COM (Common), 4
ohms, 70V and 100V terminals. Accepts up to 10
AWG terminal forks. Non-touch cover included.
Output VCA Connector: One for every two chan-
nels, 4-pin Phoenix-type connector for two VCA
control lines of +10 VDC and ground. Compatible
with Crown 1-VCAP and 4-VCAP modules.
Amp Input Connector: 3-pin Phoenix-type, high-
impedance balanced, one per amplifier channel.
Cooling
Convection cooled.
Protection
Current Limit Protection: Included.
Thermal Limit Protection: Over-temperature
thermal cutout.
DC-Fault Load Protection: Included.
Included Accessories
Power cord.
Detachable rack ears.
Screws for rack ears.
Non-touch cover for output connectors.
Phoenix-type connectors.
Spade lugs.
Optional Accessories
1-VCAP remote volume control for one channel.
4-VCAP remote volume control for four channels.
Dimensions
EIA Standard 19-inch (48.3-cm) rack mount width
(EIA RS-310-B) with rack ears, 3.5-inch (8.9-cm)
height and 12.2-inch (31.0-cm) depth behind the
mounting surface (not including non-touch cover).
4.1 inches (10.5 cm) high including feet. 13.9
inches (35.2 cm) deep from front of knobs to back
of non-touch cover.
Weight
Net Weight:
30.3 lb (13.7 kg).
Shipping Weight:
35.3 lb (16.0 kg).
Regulatory Certifications
Note: All measurements are related to 120VAC units 60
Hz in stereo mode with 8-ohm loads at 1 kHz at rated
power unless other otherwise specified. Specifications
for units supplied outside the U.S.A. may vary slightly
at different AC voltages and frequencies.