Roland DigitalDelay DD-3 Service Notes page 13

Jun. 2010
4. MODE Test
1.
Make the connections as shown in the figure below, then start the unit in
the normal usage state.
(Set the E.LEVEL and D.TIME controls to MAX and center the F.BACK
control.)
fig.test-2-2.eps
PSA-
ADAPTOR
2.
Turn the MODE control to S. 50ms, M. 200ms, and L. 800ms, and verify
that the delay time changes.
3.
Adjust the MODE control to HOLD and switch on the pedal, and verify
that a sampling sound is produced.
5. DIRECT OUT Test
1.
Make the connections as shown in the figure below, then start the unit in
the normal usage state.
fig.test-5.eps
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ADAPTOR
2.
Adjust the E.LEVEL, F.BACK, and D.TIME controls to MIN and the
MODE control to S. 50ms.
3.
Depress the pedal to make the CHECK LED light up.
The effect is switched on.
4.
Input a suitable signal from the signal generator, and verify that sound is
heard from the speaker.
5.
Insert a plug into the DIRECT OUT jack, and verify that the audible
sound stops.
6.
Disconnect the plug from the OUTPUT jack.
7.
Input signals like those shown below from the signal generator, and
verify that the output signals are at the corresponding values.
* Set the filter on the noise meter to Flat or DIN audio.
Input signal
80-Hz sine wave at 3.5 dBm
8,000-Hz sine wave at -21.5 dBm
Guitar etc.
Output signal
3 dBm±1.0 dBm
-22 dBm±1.0 dBm
6. BYPASS Test
1.
Make the connections as shown in the figure below, then start the unit in
the normal usage state.
fig.test-6.eps
2.
Depress the pedal to make the CHECK LED go dark.
The effect is switched off.
3.
Input signals like those shown below from the signal generator, and
verify that the output signals are at the corresponding values.
* Set the filter on the noise meter to Flat or DIN audio.
Input signal
80-Hz sine wave at 3.5 dBm
800-Hz sine wave at -1.5 dBm
1,600-Hz sine wave at -11.5 dBm
8,000-Hz sine wave at -21.5 dBm
7. LED and Battery Operation Test
1.
Insert a battery into the unit, make the connections as shown in the figure,
then start the unit in the usual usage state.
fig.test-7-e.eps
Stabilized power supply
2.
Adjust the MODE control to a setting other than HOLD.
3.
Set the output voltage of the stabilized power supply to 9.0 V.
4.
Depress the pedal to make the CHECK LED light up.
5.
Set the output voltage of the stabilized power supply to 7.0 V.
6.
Verify that the CHECK LED dims.
7.
Disconnect the stabilized power supply.
8.
Verify that the CHECK LED lights up brightly.
9.
Depress the pedal several times, and verify that the CHECK LED
repeatedly lights up and goes dark.
10. With the CHECK LED illuminated, disconnect the plug from the INPUT
jack.
11. Verify that the CHECK LED goes dark.
DD-3(T)
PSA-
ADAPTOR
Output signal
3 dBm±1.0 dBm
-2 dBm±1.0 dBm
-12 dBm±1.0 dBm
-22 dBm±1.0 dBm
PLUG etc.
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