Yamaha BBT 500H, Service Manual, Page: 32 / 56

BBT500H
32
1. Application
This specification provides a condition,a method,and a standard for checking BBT500H.
2. Measurement Condition and Note.
2 - 1.Keep in mind that input power supply AC voltage change with destination. it mistakes,parts may break.
2 - 2. AC VOLTAGE
J 100V+/-5V
U 120V+/-5V
H 230V+/-5V
2 - 3.Speaker outputs serves as operation by BTL(BRIDGE)connection.Separate the ground of measuring
instruments(oscilloscope,voltmeter etc)from the ground of a power supply cord.
2 - 4.Connect a speaker load resistance after the functional check (LED,SW,VR)of preamplifier, and eletrical
check.and check speaker output.
Use load resistance is 2 500W.
2 - 5.Set up position of each VR and SW like following.
In case of no appoints,Check in this state.
INPUT LEVEL → MAX
SOUND TYPE → FLAT
COMP → MIN
GAIN → MAX
MASTER → MAX
BASS → Center
LOW MID → Center
MIDDLE → Center
HIGH MID → Center
TREBLE → Center
OUTPUT → MIN
FX LOOP LEVEL → +4dB
PHONE LEVEL → MAX
LINE SOURCE → PRE EQ
SP SIM → LINE
OUTPUT LIMITER → ON
2 - 6.In case of no appoints,input signal is sine wave and its frequency is 1kHz.
Input impedance of measuring devices must be over 1M .
3. A method of checking
3 - 1.A method of start to checking
POWER ON while push HOLD SAVE 5 and FUNCTION.Then start LED check automatically.
3 - 2.LED check
a. All LED of FRONT PANEL light two times.
b. LED light in turn like following.
Lighting change carried out one by one on the right from left side of a panel.After that,surrounding
LED of a switch lights up to the circumference of the right.
c. All LED light three times and LED display indicates "2.".
3 - 3.SW check
a. Check the position of LINE SOURCE,SP SIM,OUTPUT LIMITER.
LINE SOURCE : PRE EQ
SP SIM : LINE
OUTPUT LIMITER : ON
b. Push FUNCTION while LED indicates "2.".Then LED indicates "2.0".Check the indication of
LED "2.1" → "2.2" → "2.3" → "2.4" → "2.5" → "2.6L" when push MANAL,HOLD SAVE1,in turn.
HOLD SAVE 2,
〜
HOLD SAVE 5 in turn.
TEST PROGRAM AND INSPECTIONS