Model 7720 Special Features

Meter switch:
The meter switch allows the meter to indicate either channels input level, either channels output level or the amount of stereo audio signal compression.

Sidechain:
This section modifies the control of the compressor with a mono audio signal introduced through the sidechain XLR input. A blue LED gives the user a visual indication that the circuit is active and that the sidechain audio is in control of the compressor, not the left and right audio inputs.

High Pass Filter:
The HPF rotary control allows the sidechain or main audio signal to be equalized to minimize lower frequency audio signals' effect on the compression character of the unit. The HPF affects the detection circuit, not the actual audio. The selector has six settings. The first setting does not introduce any filtration into the sidechain circuit. The next five settings are 60 Hz., 90 Hz., 130 Hz., 200 Hz. and 440 Hz. These selections allow a wide variety of choices. The high pass filter is designed so that the frequency selected is 3 dB down, with a roll-off of 12 dB per octave.

Ratio:
In addition to the ratio settings common to popular stereo compressors (2:1, 4:1, 10:1), the 7720 features a 1.5:1 setting. This allows the user to maintain control over the dynamics of the input signal without squashing the life out of the mix.

Non Stereo Application

In order to use the Model 7720 as mono compressor, you need only use the left channel inputs and outputs. All functions are as normal.

Power

External In-Line Power Supply : Each Model 7720 ships with an in-line power supply, type-dependent on country of operation. This is not a traditional "wall-wart" but simply an outboard AC transformer. DC filtering and regulation is accomplished inside the 7720 itself.

Model 7720 Specifications

Input impedance: 50K Ohms (Balanced)

Output impedance: 200 Ohms (Balanced)

Sensitivity: 20 dBu maximum at 1 KHz

Noise: Less than -80 dBu

Total Harmonic Distortion: <0.5% at 1 KHz, +4dBu

Maximum Output Level: 20 dBu

Frequency Response: 20 Hz – 20 KHz +/- 0.5 dB.

Net Weight: 6.6 pounds