Yamaha MU128, Service Manual

MU128

21

15.

1 kHz OUTPUT (R) SOUND

15  OUTPUT  R  1 kHz

Make sure that the proper signals are being output
from OUTPUT (R) and PHONES (R).

Use the same settings as specified in Note 4 for test
14.

Check items

OUTPUT (L) : -80 dBm or less
OUTPUT (R) : 1 kHz +/- 3 Hz, Sine wave, +3.0 dBm

+/- 2 dB (Load: 10 k ohm) Distortion
factor 0.25 % or less

PHONES (L) : -65 dBm or less
PHONES (R) : 1 kHz +/- 3 Hz, Sine wave, -4.0 dBm

+/- 2 dB (Load: 33 ohm) Distortion
factor 0.5 % or less

Ending the test
Press the [ENTER] button. You will then go to the
next test.

16. A/D INPUT HIGH

16  INPUT   HIGH

When HIGH is displayed on the side of INPUT in the
INPUT GAIN field, make sure that the signal input in
the A/D INPUT field changes according to the INPUT

VOLUME value and is output from OUTPUT. In addition,

input a signal at a specified level into the A/D INPUT
field and make sure that the level meter lamp on the
LCD is lit.

Note 5:
Insert  the  plugs into t he O UTPUT (L, R) and PHONES
terminals and measure the frequency, waveform and level
of individual signals output. Before starting the measurement,
set the master volume at maximum.

   
Check items
Input the sine wave data ---- 39.0 dBm, 1 kHz,
distortion factor : 0.1 or less --- In the A/D INPUT(L)

field

 (with the cable coming from the 

A/D

 INPUT (R)

terminal connected to the ground terminal).
When A/D INPUT VOLUME is set at maximum, make

sure 

that

 the specified values shown below are obtained

for OUTPUT (L) and (R).

OUTPUT (L)

: +4 dBm +/- 2 dB (Load: 10 k ohm)

Distortion factor 0.25 % or less

OUTPUT (R)

: -65 dBm or less

When A/D INPUT VOLUME is set at minimum,

make sure that the specified value
shown below is obtained

for OUTPUT (L).
OUTPUT (L)

: -70 dBm or less

Input the sine wave data ---- 39.0 dBm, 1 kHz,
distortion factor : 0.1 or less --- in the AD INPUT (R)
field (with the cable coming from the A/D INPUT (L)
terminal connected to the ground terminal).

When A/D INPUT VOLUME is set at maximum, make
su re tha t the spec ified  value s s hown bel ow are
obtained for OUTPUT (L) and (R).
OUTPUT (L) : -65 dBm or less
OUTPUT (R): +4 dBm +/- 2 dB (Load: 10 k ohm)

Distortion factor 0.25 % or less

When A/D INPUT VOLUME 

is set

 at minimum, make

sure that the specified value shown below is obtained
for OUTPUT (R).
OUTPUT (R): -70 dBm or less

Set A/D INPUT VOLUME at maximum. When the
inputting the sine wave data----33.0 dBm and 1 kHz in
the AD INPUT(L) field, make sure that the level meter
lamp on the LCD is lit.

Ending the test
Press the [ENTER] button. You will then go to the
next test.

17. A/D INPUT LOW

17  INPUT   LOW

When LOW is displayed on the side of INPUT in 

the

INPUT GAIN field, make sure that the signal input in
the A/D INPUT 

field

 changes according 

to the

 INPUT

VOLUME value and is output from OUTPUT.

 In

 addition,

input a signal at a specified level into the A/D INPUT
field and make sure that the level meter lamp on the
LCD is lit.

Use the same settings as specified in Note 6 for test
16.

Check items
Input the sine wave data----15.0 dBm, 1 kHz,
distortion factor : 0.1 or less---in the AD INPUT(L) field
(with the cable coming from the A/D INPUT (R) terminal
connected to the ground terminal).
When A/D INPUT VOLUME is set at maximum, make
sure that the specified values shown below are obtained
for OUTPUT (L) and (R).
OUTPUT (L) : +4 dBm +/- 2 dB (Load: 10 k ohm)

Distortion factor 0.25 % or less

OUTPUT (R): -60 dBm or less

When A/D INPUT VOLUME is set at minimum, make
sure that the specified value shown below is obtained
for OUTPUT (L).
OUTPUT (L)

:-72 dBm or less

Input the sine wave data of -15.0 dBm, 1 kHz,
distortion factor : 0.1 or less --- in the AD INPUT  (R) field
(with the cable coming from the A/D INPUT (L) 

terminal

connected to the ground terminal).
When A/D INPUT VOLUME is set at maximum, make
sure that the specified values shown below are obtained
for OUTPUT (L) and (R).
OUTPUT (L)

:-67 dBm or less

OUTPUT (R)

:+4.0 dBm +/- 22 dB (Load: 10 k ohm)