Roland DigitalDelay DD-3 Service Notes page 12

Jun. 2010
1. Measurement of Current Consumption
1.
Make the connections as shown in the figure, then start the unit in the
Test Mode.
(Connect the OUTPUT and INPUT jacks using an audio cable.)
fig.test-1-e.eps
PSA-
Ammeter
ADAPTOR
2.
Verify that current consumption is 35 mA or less.
2. Volume and AD/DA Test
1.
Make the connections as shown in the figure, then start the unit in the
Test Mode.
(Connect the OUTPUT and INPUT jacks using an audio cable.)
fig.test-3.eps
PSA-
ADAPTOR
2.
Turn the E.LEVEL control to near the nine o'clock position, and verify
that the CHECK LED lights up.
3.
Turn the E.LEVEL control to near the eleven o'clock position, and verify
that the CHECK LED goes dark.
4.
Turn the E.LEVEL control to near the one o'clock position, and verify
that the CHECK LED lights up.
5.
Turn the E.LEVEL control to MAX and verify that the CHECK LED goes
dark.
6. Carry out steps 2 through 5 for the F.BACK and D.TIME controls as well.
When the D.TIME control is turned to MAX, the AD/DA test is carried
out automatically. The CHECK LED lights up steadily if the test results
are OK, or flashes if the results are not OK.
12
3. Noise Test
1.
Make the connections as shown in the figure, then start the unit in the
Test Mode.
fig.test-4-1.eps
2.
Connect the noise meter to the OUTPUT jack, and verify that residual
noise is -93 dBm or less (DIN audio) or -95 dBm or less (JIS A).
3.
Connect the amp-equipped monitor speaker to the OUTPUT jack.
4.
Subject the unit to impact (by dropping it from a height of about 5 cm),
and verify that no abnormal noise is heard from the speaker.
5.
Depress the pedal several times, and verify that no switching noise occurs
and that no wires are pinched between the switch and the pedal.
6.
Depress the pedal to make the CHECK LED go dark.
The effect is switched off.
7.
Connect the noise meter to the OUTPUT jack, and verify that residual
noise is -100 dBm or less (DIN audio) or -102 dBm or less (JIS A).
8.
Disconnect the plug from the OUTPUT jack and connect the noise meter
to the DIRECT OUT jack.
fig.test-4-2.eps
PSA-
ADAPTOR
47kΩ short PLUG
9.
Verify that the CHECK LED is dark, then verify that residual noise is -104
dBm or less (DIN audio) or -106 dBm or less (JIS A).
DD-3(T)
PSA-
ADAPTOR
47kΩ short PLUG