Yamaha T3n, Service Manual

Page: 38 / 107

T5n/T4n/T3n
38
500 msec
Vburst
1 msec
20 msec
Oscilloscope display
ch 1 PK-PK
215V
T5n
T4n
T3n 1200 W/8
Ω
(42.04 dBu/ch)
1000 W/8
Ω
(41.24 dBu/ch)
700 W/8
Ω
(39.70 dBu/ch)
Note:
• Finish this inspection within 30 seconds.
2) Input 1 kHz high grade sine wave to the input terminal and check the distortion is 0.1 % or less when the output power
specified in the table below is obtained at output terminal.
T5n
T4n
T3n 643.5 W/8
Ω
(39.34 dBu/ch)
537 W/8
Ω
(38.55 dBu/ch)
379 W/8
Ω
(37.04 dBu/ch)
T3n:
1) Input 1 kHz sine wave to A channel input terminal, adjust the VR601 so that 0.225
±
0.005 Vrms is obtained between No.1
and No.2 terminal of CN611 when output voltage is 40 Vrms.
2) Input 1 kHz sine wave to B channel input terminal, adjust the VR602 so that 0.225
±
0.005 Vrms is obtained between No.3
and No.4 terminal of CN611 when output voltage is 40 Vrms.
Note:
• Input the signal to the input terminal of one channel to be adjusted only.
3-2-9. Distortion
1) Input 1 kHz high grade sine wave to the input terminal and check the distortion is 1.0 % or less when the output power
specified in the table below is obtained.
Fig. 2
3-2-10. Maximum output
Connect the 2 ohms 500 W resistance to the
output terminal.
Input the BURST signal as shown in fig. 2 to
the input terminal and adjust the input signal
level so that the Vburst output specified in the
table below is obtained at output terminal.
Measure the last one wave of the BURST sig-
nal with the peak to peak of the oscilloscope’s
MEASURE function.
Check the measured value is more than the
judgment value specified in the table below.
(See fig 2.)
T5n
T4n
T3n
Judgment value
215.0 V
195.0 V
175.0 V
Vburst output
220.0 V or more
200.0 V or more
180.0 V or more
Note:
• Perform this inspection within 30 seconds.
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