Roland JD-XA, Service Notes

34

Jul. 2015

JD-XA

5. VCF2 Check

This verifies the circuit of VCF2 (Transistor Ladder Filter).

+————————————————+
|A1-VCF2: CUT Min|
|Press [ENTER]   |
+————————————————+

1.

Verify that the frequency of the signal shown in the figure is lower than 

20 Hz

.

fig.test-a-5-1.eps

2.

Press 

Enter

.

A screen like the one shown below is displayed.

+————————————————+
|A1-VCF2: CUT Max|
|Press [ENTER]   |
+————————————————+

3.

Verify that the frequency of the signal shown in the figure is higher than 

8 kHz

.

fig.test-a-5-2.eps

4.

Press 

Enter

.

A screen like the one shown below is displayed.

+————————————————+
|A1-VCF2: RES Min|
|Press [ENTER]   |
+————————————————+

5.

Verify that no signal is output, and then press 

Enter

.

Execution advances to the check of the next wave form.

6.

For 

A2-VCF2

, 

A3-VCF2

 and 

A4-VCF2

, verify in the same way as steps 

1

through 

5

.

7.

Press 

 to advance to the next test item.

6. VCF3 Check

This verifies the circuit of VCF3 (State Variable Filter).

+————————————————+
|A1-VCF3: CUT Max|
|Press [ENTER]   |
+————————————————+

1.

Verify that a signal like the one shown in the figure is output.

fig.test-a-6.eps

2.

Press 

Enter

.

A screen like the one shown below is displayed.

+————————————————+
|A1-VCF3: CUT Min|
|Press [ENTER]   |
+————————————————+

3.

Verify that no signal is output, and then press 

Enter

.

Execution advances to the check of the next wave form.

4.

For 

A2-VCF3

, 

A3-VCF3

 and 

A4-VCF3

, verify in the same way as steps 

1

through 

3

.

5.

Press 

 to advance to the next test item.

7. Routing Check

This verifies the signal flow of each oscillator and filter.

+————————————————+
|A1-Routing1:  ON|
|Press [ENTER]   |
+————————————————+

1.

Verify that a signal is output, and then press 

Enter

.

2.

For 

A1-Routing2

 through 

9

, verify in the same way as step 

1

.

* Wave forms are different for each routing.

At last, when 

Enter

 is pressed, a screen like the one shown below 

appears.

+————————————————+
|A1-Routing10:OFF|
|Press [ENTER]   |
+————————————————+

3.

Verify that no signal is output, and then press 

Enter

.

4.

For 

A1-Routing11

 and 

12

, verify in the same way as step 

3

.

5.

For 

A2-Routing1

 through 

A2-Routing12

, verify in the same way as steps 

1

 through 

4

.

6.

For 

A3-Routing1

 through 

A3-Routing12

, verify in the same way as steps 

1

 through 

4

.

7.

For 

A4-Routing1

 through 

A4-Routing12

, verify in the same way as steps 

1

 through 

4

.

8.

Press 

 to advance to the next test item.