PIONEER PL-A25 (01) PDF MANUAL

1. Bring the FUNCTION LEVER to START and release it.

2. The Warren motor starts moving, and permits the sliding contacts to contact the terminals on the PRINTED CIRCUIT BOARD 22, providing the power to the phono motor. Thus, the turntable platter starts revolving.

3. With the motion of the Warren motor, the PLATE C 26 starts moving, and the PLATE 12 and the LEVER 18 are caused to turn by means of the CRANK LEVER 20 connected with the PLATE C 26.

4. The PU PLATE SHAFT 16 held between the LEVER 18 and the LEVER 17 is pushed until the LEVER 18 touches the PAWL 13 of the PLATE 14. This means that the tonearm makes a horizontal move and stops over the cueing point. The PLATE 12 keeps turning. The LEVER 17 is pushed open by the boss provided on the PLATE 12 which is turn-ing, and releases the PU PLATE SHAFT 16.

5. When the tip of the CRANK LEVER 20 connected with the PLATE 12 reaches the farthest point, the Warren motor comes to a halt. Then the tonearm starts lowering and rides in the groove a little before the Warren motor stops.

1. When the SCREW 8 provided at the end of the PU PLATE 9 starts pushing the PLATE 3, the STOPPER 1 joined to the PLATE 3 starts moving.

2. The pin provided at the back of the platter hits the tip of the STOPPER 1.

3. Everytime the pin hits the STOPPER 1, the STOPPER 1 moves back and then advances a little, and repeats this back and forth movement until the tonearm moves toward the center shaft when the record has finished. The STOPPER 1 engages the pin and moves in the direc-tion indicated by the arrow in Fig. 6.

4. When the STOPPER 1 is moved by the pin, the LEVER 6 is moved by the STOPPER SHAFT 4 and the SWITCH LEVER 27 is held by the LEVER 21. With the SWITCHING LEVER 27 held, the SWITCH A 25 is shorted, starting the Warren motor.

5. Shortly after the Warren motor starts re-volving, the LEVER 6 gets off the small pin provided at the back of the PLATE С 26, causing the SWITCH C 7 to short. With the SWITCH C 7 shorted, the scratching sound which the tonearm picks up at the very moment the stylus touches the record face is muted out.

6. The pin at the back of the PLATE C 26, after it has released the LEVER 6, pushes the LEVER 21 and disengages the LEVER 21 from the SWITCHING LEVER 27.

7. Even if the SWITCHING LEVER 27 is disengaged and the contacts of the SWITCH A 25 open the Warren motor keeps revolving with power supplied through the contact of the PRINTED CIRCUIT BOARD 22. When the Warren motor starts revolving, the PLATE 12 and the LEVER 18 also start turning. Then, the arm elevation pin is pushed up by the raised portion of the PLATE 12 which is turning. Shortly after, the LEVER 10 starts pushing the PU PLATE SHAFT 16. This means that the tonearm is returning to the arm rest.

8. When the sliding contact gets off the terminals of the PRINTED CIRCUIT BOARD 22, power supply is cut off, causing the phono motor, the Warren motor to stop, and one cycle of the automatic return of the tonearm has been completed.

9. The CAM LEVER 19 keeps pressing the microswitch by the sliding contact, sup-plying the power to the phono motor. When the sliding contact comes to the stop position with the tonearm return operation finished, the contact of the microswitch being pressed by the CAM LEVER 19 cuts off the power supply to the phono motor.

The Warren motor starts revolving when the FUNCTION LEVER is brought to CUT. Thereafter, the auto return mechanism performs the same operation as described in (7) and (8) in II for auto-matic return of the tonearm.

1. When the MANUAL AND RECORD SIZE SELECTOR is brought to MANUAL, the LEVER 18 is held between the PAWL 13 of the PLATE 14 and the CUT PIECE 11 of the subpanel.

2. When the FUNCTION LEVER is brought to START, the warren motor starts re-volving, and the PLATE 12 is also start-ed. But the LEVER 18 cannot move as shown in Fig. 9. In this condition, the PU PLATE SHAFT 16 is free to move in the curved opening. This means that the tonearm can move freely by hand.

3. The PLATE 12 is now in the position of play. Move the tonearm horizontally over the point at which you want to start the record and place the stylus gently in the groove. The tonearm will return to the arm rest exactly in the same manner as described in II. When the tonearm is moved off the arm rest, the PU PLATE SHAFT 16 pushes the LEVER 10 slight-ly, and if the tonearm is moved further, the SPRING LEVER (See Fig. 9.) acti-vates and pulls the LEVER 10 back to make the PU PLATE SHAFT 16 free to move in the curved opening.

1. Move the MANUAL AND RECORD SIZE SELECTOR to MANUAL, with the ARM LIFTING LEVER set to UP. The ARM LIFTING LEVER can be set to UP after the MANUAL AND RECORD SIZE SELECT-OR is moved to MANUAL.

2. Bring the tonearm over the point where you want to start the record. The PLATE 12 is in the PLAY position, but the ELEVATION BAR “A” is raised by the ELEVATION SHAFT, and pushe the ELEVATION SHAFT GUIDE PIN. This means that the tonearm is kept off the record face. (Fig. 5)

3. If the ARM LIFTING LEVER is moved to DOWN, the tonearm starts to ride in the desired groove.

a. Maladjustment of arm elevator

Possible cause: Elevator arm is not level with the panel. Tonearm pipe hold touches the elevator arm.

Remedies: See IV on page 9. Correct the position of the elevator arm.

Possible cause: Adjusting screw is loos.

Remedies: See I on page 8.

Possible causes:

a. The SCREW 8 at the end of the PU PLATE 9 is not properly adjusted. (The screw is screwed in too far.)

b. LEVER 27 is not locked in the LEVER 21.

c. Contact of SWITCH 25 is poor.

d. LEVER 10 does not snap back.

Remedies:

a. See V on page 10.

b. Repair the tip of the LEVER 21.

c. Adjust the contact of the switch, or replace.

d. See III on page 9.

Possible cause: The SCREW 8 at the end of the PU PLATE 9 is not properly adjusted. (The screw is screwed in inadequately.)

Remedy: See V on page 10.

Possible causes:

a. PRINTED CIRCUIT BOARD 22 is not properly mounted.

b. Warren motor is not properly mounted or is not secured tightly.

c. Dirt surface of the sliding contacts.

d. The contact of the sliding contacts is poor.

Remedies:

a. Correct the position of the PRINTED CIRCUIT BOARD 22.

b. Correct the position of the PRINTED P.C.D.22.

c. Clean the contact surface, or replace.

d. PLATE C 26 should be adjusted to provide better contact. Be sure to perform (c) and (d) after loosening the 2-mm screw on the PRINTED CIRCUIT BOARD 22.

Possible causes:

a. Elevation arm is adjusted too high.

b. Stylus pressure is too small.

c. Lead wires for tonearm are too tight.

Remedies:

a. See IV on page 9.

b. Adjust the counterweight properly to obtain the op-timum stylus pressure.

c. Bring out lead wires a little from the vinyl shielding. Be extremely careful when making this adjustment.

Possible causes:

a. Some or all of the six 2-mmscrews are secured too tightly.

b. Tension of the elevation spring is too weak.

c. Malfunction of elevation machanism (other than a and b above)

Remedies:

a. Loosen the screw(s).

b. Replace the spring.

c. Replace the elevation assembly.

Possible causes:

a. Some or all of the six screws are secured too loosely.

b. Tension of the elevation spring is too strong.

c. Malfunction of elevation mechanism

Remedies:

a. Tighten the screw(s).

b. Replace the spring.

c. Replace the elevation assembly.

Possible causes:

a. Selector cam is deformed.

b. Calking on the cam is loosened.

c. Drive belt is elongated.

d. Shape of the tip of the belt shifter is not proper.

Remedies:

a. Fit one E-washer under the cam.

b. Replace the cam.

c. Replace the belt.

d. Bend the tip of the belt shifter slightly downward with pliers.

Possible causes:

a. Contact of SWITCH C 7 is dirty.

b. SWITCH 7 is not properly mounted.

Remedies:

a. Clean the contact face.

b. See VI on page 10.

When the tonearm does not ride in the cueing groove properly, adjustment can be made by turning the adjustment screw (seen in the panel hole) with a screwdriver.

1. Check to see if the auto return mechanism is mounted properly.

• Move the PU PLATE SHAFT 16 slow-ly by hand and see if it moves in the center of the curved opening. If it does not, adjust the position of the auto return mechanism.

2. Set the MANUAL AND RECORD SIZE SELECTOR to 30 cm position and bring the ARM LIFTING LEVER to DOWN.

3. Start moving the tonearm by bringing the FUNCTION LEVER to START and let it ride on the record face.

4. See if the tonearm rides in the cueing groove properly. If not, make an adjust-ment by turning the adjust screw as follows:

• Turn the screw clockwise if the tone-arm tends to ride inside of the cueing groove.
• Turn the screw counterclockwise if the tonearm tends to ride outside of the cueing groove.

5. If desired, repeat steps (2) and (3) several times and then set the MANUAL AND RECORD SIZE SELECTOR to 17 cm position or 25 cm position and see if the tonearm rides in the proper groove.

If the clearance at the time the SPRING 24 and the PLATE 3 is engaged is not proper, the PLATE 3 cannot be released from the reset LEVER 2, preventing the tonearm from mak-ing an accurate return.

1. Bring the FUNCTION LEVER to START and move the PLATE 12 to the play posi-tion. Be sure to pull the power cord from the outlet.

2. See if there is a clearance of about 0.5 ~ 1 mm between the PLATE 3 and the tip of the RESET LEVER 2.

3. Move the STOPPER 1 by hand and lock the LEVER 27 to the LEVER 21. The PLATE 3 engages the reset lever.

4. If necessary, bend the spring with pliers so that the clearance between the PLATE 3 and the tip of the SPRING 24 is about 1~ 1.5 mm. Refer to Fig. 13.

If the RETURN LEVER 10 has not been snap-ped back, it cannot push the PU PLATE SHAFT 16 at the tonearm returning operation, causing the tonearm (off the record face) to fail to return to the arm rest (under this condition, the tonearm can be brought back to the arm rest by hand.)

If necessary, bend the portion marked A in Fig. 1 so that the RETURN LEVER 10 can contact the cut piece of the subpanel quicker.

A. ADJUSTMENT OF THE LEVEL OF THE ELEVATOR ARM

If the elevator arm is not level with respect to the panel, it may cause the tonearm to ride in a point inside or outside of the cueing point.

• When the elevator arm is tilted as in Fig. 14, push the tip of the elevator arm downward to make it level with the panel.
• When the elevator arm is tilted as in Fig. 15, push the tip of the elevator arm up to make it level with the panel.

B. ADJUSTMENT OF HEIGHT OF THE ELEVATOR ARM

(1) If the height of the elevator arm is not correct, it may cause the stylus to skip on the record face.

Adjust the height of the elevator arm so that the tonearm pipe rests in the middle of the sloping portion of the elevator arm with a clearance of about 0.5 mm between the pipe and the arm rest as shown in Fig. 17.

NOTE: If the adjustment screw on the elevation shaft is improperly tightened, it cause the tip of the elevator arm to tilt in C or D direction as shown in Fig. 16 and the tonearm may not ride in the cueing groove or it may ride on the elevator arm.

If the SCREW 8 at the tip of the PU PLATE 9 extends too far and push as the PLATE 3 too soon, it may cause the tonearm to start returning before the recrod has finished.

If the screw is too short and thus does not push the PLATE 3 the tonearm is not able to start automatic return operation. Adjust the SCREW 8 so that it may start pushing the PLATE 3 when the tonearm tracing the groove reaches a point about 6.5 cm from the center shaft.

If the contacts of the SHORT SWITCH C 7 are not properly adjusted, a scratching sound may be reproduced at the very moment the Stylus touches the record face. Make the adjustment of the contact in the following steps.

BRING THE FUNCTION LEVER TO START

The warren motor starts revolving and when the PLATE 12 reaches PLAY position, the motor comes to a halt.

Make an adjustment with a head screw-driver so that the bakelite plate touches the REST LEVER 6 as the warren motor stops. Also make an adjustment so that there is a gap of 0.5 mm between the contacts as shown in Fig. 19.