928 Mixing Console
Alignment E 3/19Edition: 07.02.01
3.3.3 Input unit stereo 1.928.250
Distortion:
• Feed test signal with nominal level (1 kHz, typ. +6 or +10 dBu)
to the LINE 1 LEFT input.
• Set the LINE GAIN potentiometer to center position (CAL.),
switch filters off, and set the fader to its 0 dB position.
• Remove the Input unit from the console and reconnect it via
the bus adapter (optionally available, order no. 1.228.332.00).
• Route the signal to Master A (ΣA).
• Connect the distortion analyzer to the PF INSERT SEND con-
nector of Master unit A left.
• Set VR1 on the Side Board (left channel) to minimum distor-
tion (typical value: <80 dB @ 1 kHz).
• Feed test signal with nominal level (1 kHz, typ. +6 dB or +10
dBu) to the LINE 1 RIGHT input.
• Connect the distortion analyzer to the PF INSERT SEND con-
nector of Master unit A right.
• Set VR2 on the Side Board (right channel) to minimum distor-
tion (typical value: <80 dB @ 1 kHz).
Level:
• Feed test signal with nominal level (1 kHz, typ. +6 dB or +10
dBu) to the LINE 1 LEFT input.
• Connect the AF voltmeter to the PF INSERT SEND connector
of Master unit A left.
• Set the level with trimmer potentiometer VR3 on the Side
Board to nominal level.
Meter PPM (JP7 set to 2-3, section 3.1.2):
• Feed test signal with nominal level (1 kHz, typ. +6 or +10 dBu)
to the LINE 1 LEFT input.
• Set trimmer potentiometer RV1 on the Main Board for 0 dB
indication on the left-channel meter.
• Feed test signal with nominal level (1 kHz, typ. +6 or +10 dBu)
to the LINE 1 RIGHT input.
• Adjust trimmer potentiometer RV2 on the Main Board for 0 dB
indication on the the right-channel meter.
Meter VU (JP7 set to 1-2, see section 3.1.2):
• Feed test signal with nominal level –6 dB (1 kHz, typ. 0 or
+4 dBu) to the LINE 1 LEFT input.
• Adjust trimmer potentiometer RV1 on the Main Board for 0 dB
indication on the the left-channel meter.
• Feed test signal with nominal level –6 dB (1 kHz, typ. 0 or
+4 dBu) to the LINE 1 RIGHT input.
• Adjust trimmer potentiometer RV2 on the Main Board for 0 dB
indication on the the right-channel meter.
Note:
Usually, a 6 dB lead is used to compensate for the lower rise
time of the VU meter (example: If the nominal level is +10 dBu,
0 VU is indicated with an input level of +4 dBu).
TONE L TONE R
RV5 RV6
J1 J2
J3
J4
1 2
3 4
5 6
RV7
RV8
NULL 1
NULL 2
J5 J6
J9
J8
RV1 RV2
METER
CAL L
METER
CAL R
J7
Main Board
1.928.250
(component side)
Side Board
1.928.253
(solder side)
J1 J2 VR1 VR2 J3 J4 J5 VR3