Yamaha QL5 Manual page 16

QL5/QL1
INSPECTIONS
1. Preparation
1-1. Measuring Instruments
Use measuring instruments which can measure the inspection
items accurately with confi dence.
Input impedance of the measuring device should be 100 kΩ or more.
• System Two
Multi-Volt Meter
Filter (12.7 kHz, –6 dB/OCT)
Level meter
1-2. Parameters
Unless otherwise specified, the parameter settings are as
follows.
• Set the WORD CLOCK to INT 48 kHz.
• Set the "+48 V MASTER" to ON.
• Turn on only the channel being measured.
PAN :
GAIN :
FADER :
PHONES LEVEL :
• 0 dBu = 0.775 Vrms
• 0 dBFS = 0 dB, full scale
• The oscillator output impedance should be 150 Ω.
• Measure the noise level with a 12.7 kHz, –6 dB/octave low
pass fi lter.
(For measurement, use the average values and not effective
values.)
When using the Audio Precision Audio Analyzer System
Two and 2700 series, set the Detector Reading Rate to 4/
sec.
• Correct the distortion measurement with an 80 kHz, –18
dB/octave low pass fi lter.
For analog output inspection, add or change parameter
settings as follows.
• For maximum output measurement, unless otherwise
specifi ed, output 0 dB from the internal oscillator.
• Set the analog output loads as follows:
OMNI OUT:
PHONES:
1-3. Updating the Program
If the main program is not the latest version, it is required to
update it to the latest version.
* For the latest version, download the latest program from the
YSISS home page and save it in the USB memory device.
(1) How to check the version of the main program
Press the [SET UP] button on the LCD screen and the current
version will be shown in the "SETUP" page screen.
(2) How to update the program
For the program updating procedure, refer to the "UPDATING
FIRMWARE". (See page 154.)
116
CENTER
MIN
NOMINAL (0 dB)
MAX
600 Ω
8 Ω
1-4. Initialization
For initialization, turn on the power while pressing the B [SEL]
switch and execute "INITIALIZE ALL MEMORIES".
(See page 155.)
1-5. Fader Calibration
For the procedure of calibrating faders, refer to "FADER
CALIBRAION". (See page 159.)
1-6. Color Bar Calibration
For the procedure of calibrating the color bar, refer to "COLOR
BAR AND CH NAME LCD CALIBRATION". (See page 161.)
1-7. CPUQL circuit board MRAM Backup Check
Check that "Memory Error! Current Memories were Initialized"
does not appear on the LCD screen when the power is turned
on.
2. ANALOG IN/OUT Characteristic Inspection
2-1. QL5: INPUT 1-16 → OMNI OUT 1-16
QL1: INPUT 1-8 → OMNI OUT 1-8
Parameters:
QL5: Input the analog signal from INPUT (XLR) of CH 1-16
and measure the signal output from OUTPUT of CH 1-16.
Assign OMNI IN CH 1-16 to OMNI OUT 1-16.
QL1: Input the analog signal from INPUT (XLR) of CH 1-8
and measure the signal output from OUTPUT of CH 1-8.
Assign OMNI IN CH 1-8 to OMNI OUT 1-8.
A. GAIN MIN
1 Gain
Input Frequency Input Level
1 kHz +10 dBu
2 Distortion
Input Frequency Output Level
1 kHz +22 dBu
3 Noise level
Parameters: Short the CH IN to be measured with 150 Ω.
Permissible Range
–80 dBu or below
4 Residual noise
(QL5: OMNI OUT 1-16 / QL1: OMNI OUT 1-8)
Parameters: QL5: Set INPUT CH 1-16 to OFF.
QL1: Set INPUT CH 1-8 to OFF.
Permissible Range
–88 dBu or below
Prescribed Output Level Permissible Range
+4 dBu +4±2 dBu
Permissible Range
0.01 % or below