Solid State Logic X-Logic Series User Manual

Page 43

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Page D-5

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.

5K01**

5K01**

2

3

1

2

3

1

0V

+

0V

+

To measuring
equipment

From unit

under test

1

2

1

Resistor tolerance should ideally be 0.01%
Absolute level measured will depend upon the input
impedence of the measuring equipment.

1.
2.

Note

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