X-Rack Dynamics Module

D.4.3 Compressor Threshold

 

 

 

 

 

 

 

 

Adjustment:

1.

Connect the level meter to the Output and set the oscillator level for

 

 

–28.35dBu.

 

2.

Measure the DC voltage at test point TP14 relative to 0VA and adjust VR9

 

 

(COMP_THOLD) for 0V ±10mV.

D.4.4 Compressor Law

 

 

 

Adjustment:

1.

Set the oscillator level for +20dBu.

 

2.

Connect the level meter to the Output. Check for +20dBu ±0.5dB.

 

3.

Set the compressor ratio control fully clockwise and press in the

 

 

compressor FST ATT and PK switches.

 

4.

Adjust VR10 (COMP_LAW) for a level of 14dBu ±0.1dB.

 

5.

Reset the compressor ratio control fully anti-clockwise.

D.4.5 Gate Threshold

 

 

 

Adjustment:

1.

Set the oscillator level for +10dBu and connect the level meter to the

 

 

Output.

 

2.

Set the gate/expander to ‘gate’ by releasing the EXP switch, set the gate

 

 

range and gate threshold controls fully clockwise.

 

3.

Adjust VR8 (GATE_THOLD) so that the gate just switches on.

 

4.

Check this adjustment by changing the oscillator level a little. Re-adjust

 

 

VR8 if necessary so that the gate just opens when a +10dBu signal @ 1kHz

 

 

is applied.

D.4.6 Output Balance

 

 

 

Equipment Required:

 

Calibrated audio oscillator, audio level meter and a ‘balance’ adaptor (see

 

 

below).

Test Signal:

 

1kHz sine wave at +24dBu.

Input and Output:

 

Oscillator to the Input of the channel being tested, Output to the level

 

 

meter via the ‘balance’ adaptor.

Unit Setup:

 

Ensure that all front panel switches are off and all controls are set fully

 

 

anti-clockwise.

Adjustment:

 

Connect the test equipment to the each channel in turn and adjust VR13

 

 

(BAL) for minimum level (< 55dBr).

D.4.7 ‘Balance’ Adaptor

For the output balance adjustment, a ‘balance’ adaptor such as that illustrated here will be required. This adaptor consists of a pair of close tolerance resistors in an in-line cable and is used to sum together a balanced output in order to correctly adjust the level balance of the measured output; perfect balance should result in complete signal cancellation.

 

1

 

3

 

 

0V

 

 

 

 

 

1

 

 

 

From unit

2

5K01**

 

 

 

+

 

 

 

To measuring 2

under test

 

1

2

+

 

3

5K01**

 

equipment

 

 

 

1 0V

Note 1. Resistor tolerance should ideally be 0.01%

2.Absolute level measured will depend upon the input impedence of the measuring equipment.

Page D-5

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Image 43
Solid State Logic X-Logic Series Compressor Threshold, Compressor Law, Gate Threshold, 7 ‘Balance’ Adaptor, D-5