Yamaha imx644 Service Manual page 35

No. Item
18 Total harmonic distortion
STEREO INPUT 1L/R to 4A L/R
→ OUTPUT 1 L/R, 2 L/R
19 Total harmonic distortion
STEREO INPUT 4A L/R
→ RECOUT A L/R
20 Matrix indicators and MEMORY button's
indicators
21 [SIGNAL/PEAK] indicator of MONO
INPUT 1 to 6
22 Operation of volume control and check
LEVEL meter
Specification
• 0.1 % or less
• 0.1 % or less
• Confirm that the matrix indicators and MEMORY
button's indicators light as shown figure 11.
MATRIX
indicator
Lighting
Lighting
Figure 11
• Confirm that the [SIGNAL/PEAK] indicator of
corresponding channel lights RED.
* Input gain is set to MINI.
[OUTPUT 1 & OUTPUT 2 Level meters]
Confirm that the [PEAK] lights RED.
Confirm that the [-8] lights YELLOW.
Confirm that the [-14] lights YELLOW.
Confirm that the [-20] lights GREEN.
Confirm that the [-32] lights GREEN.
Confirm that the [-44] lights GREEN.
[OUTPUT 3 & OUTPUT 4 SIGNAL/PEAK indicators]
Confirm that the [SIGNAL/PEAK] indicators light
RED.
• Turn the OUTPUT volume control counterclockwise
and confirm the following things.
[OUTPUT 1 & OUTPUT 2 Level meters]
Confirm that the [PEAK] turns off first and [-44] turns
off last.
[OUTPUT 3 & OUTPUT 4 SIGNAL/PEAK indicators]
Confirm that the [SIGNAL/PEAK] indicator color
changes from RED to GREEN and then turns off.
When the OUTPUT volume control reaches at the
minimum position, confirm the following things.
[Measurement with the audio analyzer]
• -70 dBu or less (DIN-A)
• Input the 1 kHz, -1.8 dBu sine wave
to the channel to be checked.
• 22 kHz LPF
• Set the volume control of the chan-
nel to be checked as shown in fig-
ure 10.
• Input the 1 kHz, -1.8 dBu sine wave
to the channel to be checked.
• 22 kHz LPF
• Set the volume control of the chan-
nel to be checked as shown in fig-
ure 10.
• Press and hold the MEMORY [B]
button for 2 seconds or longer.
MEMORY
Lighting Lighting
• Input the 1 kHz, -16 dBu sine wave
to the channel to be checked and
confirm each channel MONO1 to
MONO6.
• All [PAD] switches: OFF
• Input the 1 kHz sine wave to the
channel to be checked so that the
output voltage becomes +18 dBu ±1
dB.
• INPUT volume controls: MIN
• Measure the output voltage with the
audio analyzer
• DIN-A
IMX644
Procedure
35