Voltage Gain, 1 kHz, 1.4V sensitivity,
                       CH1,
                               30.5 dB (4/8 ohm);
                               34 dB (70V);
                               37 dB (100V).
                       CH2,
                               32.1 dB (4/8 ohm);
                               34 dB (70V);
                               37 dB (100V).
                       CH4,
                               34 dB (4/8 ohm);
                               34 dB (70V).
                       CL1,
                               30.5 dB at (4/8 ohm).
                       CL2,
                               32.1 dB at (4/8 ohm).
                       CL4,
                               34 dB (4/8 ohm).

                       AC Line Requirements:
                       Note: North American CH 1, CL 1, CH 2 and CL
                       2 units are 60 Hz only. All other models are
                       50/60 Hz. Voltages are ±10%.

                       AC Line Current,
                       CH 1 & CL 1,
                               100 Volts: 7.6 A;
                               120 Volts: 6.3 A;
                               230-240 Volts: 3.5 A.
                       CH 2 & CL 2,
                               100 Volts: 11.4 A;
                               120 Volts: 9.5 A;
                               230-240 Volts: 5.0 A.
                       CH 4 & CL 4,
                               100 Volts: 8.5 A;
                               120 Volts: 7.1 A;
                               230-240 Volts: 3.7 A.

                       AC Line Connector: Detachable 15A IEC
                       connector with country-specific plug.
                       Performance
                       Frequency Response, 20 Hz to 20 kHz at 1
                       watt,
                       CH 1, CH 2, CL 1 & CL 2: ±0.1 dB.
                       CH 4 & CL 4: ±0.25 dB.
                       Phase Response: ±15 degrees from 20 Hz to
                       20 kHz at 1 watt.
                       Signal to Noise Ratio, A-Weighted,
                       CH 1, CH 2, CL 1 & CL 2: Better than 105 dB
                       below rated 1-kHz power. 
                       CH 4 & CL 4: Better than 102 dB below rated
                       1-kHz power.
                       Total Harmonic Distortion (THD), 1 kHz at
                       rated power: 0.5% or less true THD from 20Hz
                       to 20 kHz.
                       Intermodulation Distortion (60 Hz and 7 kHz
                       at 4:1): Less than 0.1% at rated power to 30 dB
                       below rated power at 8 ohms.

               Damping Factor (8 ohm),
                CH 1, CH 2, CL 1 & CL 2: Better than 400                 from 10 Hz to 400 Hz.
                       CH 4 & CL 4: Better than 700 from 10 Hz to 400 Hz.
                       Crosstalk, 20 Hz to 20 kHz: Better than 50 dB
                       below rated power.
                       Common Mode Rejection (CMR): Better than
                       70 dB from 20 Hz to 1 kHz.

                       DC Output Offset (Shorted Input): ±10 mV Controls 
Level: A detented rotary level control for each channel
located on the rear panel.

Power: An on/off rocker switch located on the front  panel. 

Mode: A two-position switch located on the back panel which, when turned to “Stereo,” operates the amplifier as two independent channels. When “Bridge” is selected, the amplifier bridges the two output channels for twice the output voltage.

Channel Operation Switch (CH Series only): A two-position switch located on the back panel which, when turned to 4/8 Ohm, sets the amplifier to drive low-impedance speaker loads. Turning the switch to70V/100V (70V only on the CH4) sets the amplifier to drive distributed high-impedance speaker loads and inserts a 70-Hz high-pass filter into the signal chain to prevent step-down transformer saturation.

Indicators Signal: A green indicator for each channel which
flashes when a very low-level signal (>-40 dBm) ispresent at input. May be used for troubleshooting cable runs.

Clip: A red indicator for each channel which turns on when distortion becomes audible in the amplifier output.

Fault: A red indicator for each channel which indicates amplifier has muted output. Normally off. Status may be monitored remotely by plugging into  back-panel RJ11 Fault jack. 
Power: A blue indicator that turns on when the amplifier has been turned on and has power. 
Input/Output Input Connector (standard module): One Neutrik Combo connector for each channel which features a balanced ¼-inch (6.35-mm) phone jack and a 3-pin female XLR connector, in parallel with a barrier striptermination.
Input Stage: Input is electronically balanced and employs precision 1% resistors.

Input Impedance: Nominally 20 k ohms, balanced. Nominally 10 k ohms, unbalanced.

Input Sensitivity: Channel independent. Factory set t 1.4 volts for standard 1-kHz, 8-ohm power. 26-dB gain and 0.775-volt sensitivity available as a ServiceOption.
Output Connectors,  CH1 and CH2: Four-terminal touch-proof barrier block, one per channel, allows connection of load to 8-ohm, 4-ohm, 70V or 100V outputs. CH4: Four-terminal touch-proof barrier block.
CL Series: Four-terminal touch-proof barrier block.
Output Signal, 
Stereo: Unbalanced, two-channel. 
Bridge-Mono: Balanced, single-channel. Channel 1controls are active; Channel 2 should be turned down.
Protection
CH and CL Series amplifiers are protected against shorted, open or mismatched loads; overloaded power supplies; excessive temperature, chain destruction phenomena, input overload damage and high-frequency blowups. They also protect loudspeakers from input/output DC, large or dangerous DC offsets and turn-on/turn-off transients.
Options
Service Options: SST-SBSC: variable Linkwitz-Riley stereo crossover with mono-summed sub-bass outputs; SST-MX: 100-Hz Linkwitz-Riley crossover with stereo sub-bass output; SST-SX: 80-/120-Hz switchable Linkwitz-Riley crossover with mono summed sub-bass output.

 Dimensions,
Width (all models): EIA Standard 19-inch rack mount (EIA RS-310-B);
Height (all models): 5.25-inch
Depth (behind front mounting surface), CH 1, CH 2, CL 1 and CL 2: 12.25-inch CH 4 and CL 4: 16.25-inch

Weight, CH 1: 40.6 pounds;  CH 2: 48.3 pounds ;CL 1: 32.6 pounds;CL 2: 40.3 pounds;CH 4 and CL 4: 33.3 pounds