Solid State Logic X-Logic Series Compressor Threshold, Compressor Law, Gate Threshold, 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.

	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.

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