Solid State Logic X-Rack E Series LF EQ Maximum Gain, Output Balance, ‘Balance’ Adaptor

X-Rack Owner’s Manual

K.4.2

K.4.3

	4.	Switch BLK in and re-adjust LMF Frequency for maximum level.
	5.	Adjust VR16 for +18dBu ±0.25dB.
	6.	Reset LMF Gain to its centre indent position and release the BLK switch.
LF EQ – Maximum Gain		Re-check the audio level meter for 0dBu.
	1.	Ensure that the BLK switch is released.
Adjustment:
	2.	Set LF Gain to maximum and select LF BELL. Set the audio oscillator for
		80Hz and adjust LF Frequency to find the maximum level on the audio
	3.	level meter.
		Adjust VR17 for +15dBu ±0.25dB.
	4.	Switch BLK in and re-adjust LF Frequency for maximum level.
	5.	Adjust VR18 for +18dBu ±0.25dB.
	6.	Reset LF Gain to its centre indent position, release the BLK switch and de-
Output Balance		select LF BELL. Re-check the audio level meter for 0dBu.
		Calibrated audio oscillator, audio level meter and a ‘balance’ adaptor (see
Equipment Required:
Test Signal:		below).
		1kHz sine wave at +24dBu.
Input and Output:		Oscillator to the Input of the channel being tested, Output to the level
Unit Setup:		meter via the ‘balance’ adaptor.
		Ensure that all front panel switches are off and all controls are set fully
Adjustment:		anti-clockwise.
		Connect the test equipment to the each channel in turn and adjust VR19
		(BAL) for minimum level (< 55dBr).

‘Balance’ Adaptor		0V	1				3	–
For the output balance adjustment, a ‘balance’
adaptor such as that illustrated here will be				5K01**		1
required. This adaptor consists of a pair of	From unit	+	2				2		To measuring	2
close tolerance resistors in an in-line cable and	under test		3		**	1		+
				5K01
is used to sum together a balanced output in		–					1	0V	equipment
order to correctly adjust the level balance of the
measured output; perfect balance should result	Note 1.	Resistor tolerance should ideally be 0.01%
in complete signal cancellation.
	2.	Absolute level measured will depend upon the input
		impedence of the measuring equipment.

Page K-6