Inspections & Mechanical Check Point （ - Yamaha Silent Cello SVC110 Service Manual

SVC110/SVC110S
I
INSPECTIONS
1. Preparations
1-1 Unit Setting
Unless otherwise specified, the controls and switches are to be set as follows.
AUX VR
VOLUME
POWER switch
REVERB switch
The [PHONES] and [LINE OUT] terminals are to be terminated with the following resistors.
PHONES
LINE OUT
1-2 Measuring instruments and jigs
The following measuring instruments and jigs are used for inspection.
Measuring instruments : low-freqency oscillator, level meter.
Jigs
2. Inspections
Items
Output level 1 PHONES (L)
PHONES L PHONES (R)
Output level 2 PHONES (L)
PHONES R PHONES (R)
Output level 3 LINE OUT (L)
LINE OUT L LINE OUT (R)
Output level 4 LINE OUT (L)
LINE OUT R LINE OUT (R)
Output level 5
PHONES (L/R) : -21.5 ±2 dBu
PICKUP INPUT
(1 kHz)
Output level 6
PHONES (L/R) : -18.5 ±2 dBu
PICKUP INPUT
(12 kHz)
Output level 7
PHONES (L/R) : -17.5 ±2 dBu
PICKUP INPUT
(120 Hz)
Output level 8
PHONES (L/R) : -24 ±4 dBu
PICKUP INPUT
(60 Hz)
Noise level
PHONES (L/R) : Less than -60 dBu
PHONES (L/R)
Noise level
LINE OUT (L/R) : Less than -60 dBu
LINE OUT (L/R)
Noise level
LINE OUT (L/R) : Less than -60 dBu
LINE OUT (L/R)
* Check by the sense of hearing.
RM (ROOM) : Reverberation time 1.5 sec.
REVERB MODE HL 1 (HALL1) : Reverberation time 1.5 sec.
HL 2 (HALL2) : Reverberation time 2.0 sec.
14
: Maximum
: Maximum
: ON (REV OFF mode)
: RM
: 150 ohms
: 10 k-ohms
* Use a flat filter when measuring the noise level.
: AC adaptor (PA-3C), powered speaker, stereo sound source (such as a CD player), headphones.
Specification
: -5 ±2 dBu
: Less than -60 dBu
: -60 dBu or less
: -5 ±2 dBu
: -4.5 ±2 dBu
: Less than -60 dBu
: Less than -60 dBu
: -4.5 ±2 dBu
Applied signal and settings
AUX IN L : -20 dBu/1 kHz, sine wave
AUX IN R : -20 dBu/1 kHz, sine wave
AUX IN L : -20 dBu/1 kHz, sine wave
AUX IN R : -20 dBu/1 kHz, sine wave
Apply a 1 kHz -30 dBu sine wave signal
to the CN1 1st pin of the MA circuit board.
Apply a 12 kHz -30 dBu sine wave signal
to the CN1 1st pin of the MA circuit board.
Apply a 120 Hz -30 dBu sine wave signal
to the CN1 1st pin of the MA circuit board.
Apply a 60 Hz -20 dBu sine wave signal
to the CN1 1st pin of the MA circuit board.
Apply ground to the CN1 1st pin of the MA
circuit board.
(Connect pin 1 and pin 2.)
Play the strings using the fingers, then stop
the vibration of the strings and check the
reverberations.
[
0 dBu=0.775 Vrms
Set the unit as specified in 1-1
POWER SW : ON (Reverb off)
REVERB SW: RM
POWER SW : REV.ON
REVERB SW: RM
Set the unit as specified in 1-1
and the [POWER] switch to the
[REV.ON] position; set the
[REVERB] switch to the appropriate
position.
]