Yamaha N12 - n12 Digital Mixing Studio, Service Manual

Page: 83 / 245

83
n8/n12
• Test (Test program mode)
1. Analog characteristics
Set 0 dBu = 0.775 Vrms and 0 dBV = 1 Vrms.
1-1. Preparations
1-1-1. Load resistance
Load resistance of each output terminal is as follows:
C-R/AUX PHONES: 40 ohms (3W or more)
STEREO OUTPUT (LINE): 600 ohms
C-R OUTPUT (n8)/C-R OUTPUT A-C (n12):
600 ohms
AUX OUTPUT (n12 only): 600 ohms
STEREO OUTPUT (RCA): 10k ohms
INSERT (OUTPUT) 1-4 (n8)/1-8 (n12):
10k ohms
1-1-2. Controller settings
Unless otherwise speci fi ed, set up as follows.
• CH INPUT
GAIN Volume : MIN
PAD SW (CH1-4 (n8)/CH 1-8 (n12)) : Off
Hi-Z SW (CH4 (n8)/CH 8 (n12)) :
Off
ON SW : Off
PHANTOM (+48V) SW : Off
• MASTER Control
2TR TO ST ON SW : Off
• OUTPUT/METER Control
C-R/AUX PHONES Volume : MAX
• Control Room Monitor
Mute : Off
Controllers which are not described above can be set to any
settings.
1-1-3. Input signal
Use 1 kHz sine wave for input signal unless otherwise speci fi ed.
Speci fi cations of input signal to each input terminal is as follows:
INPUT A/B
1-4 (n8)
1-8 (n12)
INPUT
5-8 (LINE) (n8)
9-12 (LINE) (n12)
INPUT
5-8 (RCA) (n8)
9-12 (RCA) (n12)
2TR IN
System Balance Unbalance Unbalance Unbalance
Impedance 150 ohms 20 ohms * 20 ohms * 20 ohms *
* 600 ohms is available.
1-1-4. Operation mode
While holding down the [
A
] (STOP) key and [
I
] key
simultaneously, turn on the power and conduct tests in service
test mode.
1-1-5. Notice
If a result of test related to noise (distortion factor, equivalent
input noise, crosstalk, mute, residual noise, etc.) is NG, execute
factory set and then test again. Refer to
“4. Factory set pro-
cedure”
section for procedures of factory set. (Page 82)
1-2. Input system
1-2-1. Preparations
Set the n8 or n12 to AD/DA through (Input test mode) for test.
Refer to
“2-12. AD/DA through connection”
for details of
setup procedure and internal connection. (Page 78)
1-2-2. Gain (Input)
Set up ON switches as follows:
ON SW of all CH : On
Set up GAIN volumes and PAD switches as in the following table.
Unit: [dBu]
INPUT
INPUT
LEVEL
GAIN PAD
ST OUT (LINE)
L R
INPUT A
1,3 (n8)
1,3,5,7 (n12)
-16 MIN
ON -22 ± 2 –
!
q
OFF +4 ± 2 –
-60 MAX OFF +4 ± 2 *2 –
! w
INPUT A
2,4 (n8)
2,4,6,8 (n12)
-16 MIN
ON – -22 ± 2
! e
OFF – +4 ± 2
-60 MAX OFF – +4 ± 2 *2
! r
ST CH LINE
5,7 (n8)
9,11 (n12) *1
+4 MIN
–
+4 ± 2 –
! t
-26 MAX +4 ± 2
*2
–
! y
ST CH LINE
6,8 (n8)
10,12 (n12) *1
+4 MIN
–
– +4 ± 2
!
u
-26 MAX – +4 ± 2 *2
! i
ST CH RCA
5,7 (n8)
9,11 (n12)
-7.8 *3 MIN
–
+4 ± 2 –
! o
-37.8
*3
MAX +4 ± 2
*2
–
!
!0
ST CH RCA
6,8 (n8)
10,12 (n12)
-7.8 *3 MIN
–
– +4 ± 2
!
!1
-37.8 *3 MAX – +4 ± 2 *2
! !2
2TR IN L *2 -7.8 *3 – – +4 ± 2 *2 –
}
! !3
2TR IN R *2 -7.8 *3 – – – +4 ± 2 *2
*1:
Connect plugs at the same time to the ST CH LINE L/R
pair connectors. (i.e. n8: 5 (L) and 6 (R), 7 (L) and 8 (R) /
n12: 9 (L) and 10 (R), 11 (L) and 12 (R))
*2:
Check that level differences between channels are as
follows:
Tolerance
2 dB or less
*3:
-7.8 dBu = -10 dBV, -37.8 dBu = -40 dBV
1-2-3. Frequency characteristics (Input)
Set up as in descriptions marked
w
,
r
,
y
,
i
,
!0
,
!2
and
!3
in procedure
1-2-2.
Check that the levels of each output when
the frequency is 20 Hz and 40 Hz are within the range shown
below compared with the level when the frequency is 1 kHz.
Tolerance
1/-3 dB