SHARP RP-2626H Stereo Turn Table Instruction Manual

SHARP RP-2626H Stereo Turn Table

In the interests of user safety, the set should be restored to its original condition, and only parts identical to those specified to be used.

SPECIFICATIONS

Specifications are subject to change without prior notice.

DESIGNATION OF PARTS

DISASSEMBLY
RE an Aea 7oe th Amnina Disconnect all leads connected to the back of the unit.

1. Remove fourteen (14) screws retaining the bottom cover. (Refer to Figure 3—1)
2. Mechanical parts removal. (Refer to Figures 13-1 and 15—1)

Check the preset voltage before connecting the mains plug to a mains outlet. If the setting is different from your local supply mains voltage, the selector must be reset as follows. Rotate the selector with a screwdriver, aligning the arrow mark to your local voltage number.

Note
Since this set uses a DC motor, the Operation is regardless of whether a household power supply is 50Hz or 60Hz.

MOUNTING OF PHONO-CARTRIDGE ON HEAD-SHELL

1. Referring to Figure 3-3, connect the cartridge to the 2. Provide a distance of 50mm between the stylus end and head-shell by use of Jeads.
2. (Refer to Figure 3—4)

BEHAVIORS OF CONTROL CIRCUIT
This control circuit is a frequency generator servo type so this detected output is considered frequency, thereby: detecting the output of the dynamo synchronizing with the motor controlling the speed of a disk to be used.

Refer to Figures 4-1, 4—2 and 5-1.

1. FREQUENCY GENERATOR
   The frequency generator consists of a 72-pole magnet, 36-tooth multi-gap head, and coil and it creates sine waves of 20 Hz and 27 Hz respectively when an LP disk and EP disk are played.

2. AMPLIFIER CIRCUIT
   The amplifier circuit is of a 2-stage differential type and it amplifies the output of the frequency generator to produce a square wave of 50% duty cycle. Semi-variable resistor VR1 (330 ohm B) is to adjust the square wave so that its duty cycle becomes 50%: this is because the output of this circuit will be permitted to be multiplied by the frequency multiple circuit.

3. FREQUENCY MULTIPLE CIRCUIT
   The frequency multiple circuits are to differentiate conversion output and non-conversion output (the two are of the square wave) obtained | from the said id amplifier circuit to create pulses each having a swifter rising and narrow width.

4. REFERENCE VOLTAGE CIRCUIT
   The reference voltage circuit produces a reference voltage that determines the rotation number of the motor, in which the output of the voltage-regulated circuit is resistor-divided to be made a constant voltage. A variable resistor is provided to permit the voltage-division ratio to be varied, thereby the motor’s rotation number being variable. Waveforms of the Circuits (with DC 20 V) (The points are identical to those indicated in the annexed ‘“‘Circuit Diagram’ Figure 5—1.)

5. COMPARATOR CIRCUIT
   The comparator circuit consists of a differential comparator circuit and switching transistor and it is to compare the level of the saw tooth wave 4) and that of the reference voltage to each other so that there will be on-off pulses available. off-pulse is obtained when ‘the height of saw tooth wave is lower than the level of reference voltage while on-pulse when the former is higher than the latter: a variation of the frequency (that of the motor’s rotation number) is converted into an average variation of the output pulse.

6. LOW-PASS FILTER
   The low-pass filter is a 2-stage CR primary low-pass filter that is to have the output pulse of the comparator circuit be smoothed.

7. AMPLIFIER CIRCUIT
   The amplifier circuit is to amplify the output of the low-pass filter to apply it to the hall device.

8. POSITION DETECT CIRCUIT
   The position-detecting circuit serves to detect the N-pole or Spole of the rotor magnet using a hall device so that it can determine the sequence by which 4 drive coils will be given a current one after another. Meanwhile, the voltage applied to the hall device is regulated by the control circuit described in steps 1) to 8) above, and the output voltage of the hall, device is varied according to a variation of the rotation number of the motor.

9. DRIVE CIRCUIT
   The drive circuit is the one that amplifies the output of the hall device to have a current run in the drive coil.

10. FEEDBACK CIRCUIT
    The feedback circuit carries out a negative feedback operation from the drive circuit to the amplifier circuit thus letting the entire operation of the control circuit be more stabilized.

CIRCUIT MOTION WHILE THE ROTATION NUMBER IS VARIED
Circuit Motion while the Rotation Number is varied In which, Ny > No > N3

ADJUSTMENT OF THE MECHANISM

AUTO READ-IN ADJUSTMENT
(Refer to Figure 6—1) Before the set leaves the factory, the descending position of the stylus has been adjusted properly but it may be, however, that under automatic play mode, the stylus top end cannot descend on the starting groove correctly because of the adjustment having been deviated due to vibration during the transportation or if a disc record outside the specification is used. If the descending position of the stylus is not correct, adjust the screw provided at the bottom of this unit. When the stylus descends outside the record periphery, rotate the screw toward ‘IN’. While, when it descends inside the starting groove of the record, rotate the screw toward ‘OUT’. The motion of one graduation of the screw can change the descending position by 1.5mm.

STYLUS POSITION ADJUSTMENT
(Refer to Figure 6—2) In the auto return auto lead-in operation or cueing-up Operation, the stylus tends to scratch a record disk surface if its setting height is lower than usual, or it may not descend exactly on the disk surface or hit the dust cover if the height is higher than normal. Therefore, follow the following procedures to ensure the rated stylus position. Positionally arranged the eccentric pin groove of the seesaw fever to direct to its longitudinal direction. See the photo.

Set the cueing lever at ‘the “’ Up ” position and rotate the nut of the elevation shaft to provide a clearance or approx. 4mm between the stylus top and the disk surface. Place the unit in ‘‘auto lead-in’’ mode to allow the tonearm to come to above the disk surface, then stop the tonearm and adjust the eccentric pin of the seesaw lever so that a distance between the stylus top and the disk surface becomes 8 an mm (at the time, keep. the cueing lever at “Down” position).

AUTO RETURN ADJUSTMENT
(Refer to Figure 6—3) Turn the screw clockwise when the return motion is too fast (before the end of the performance) and turn it counterclockwise when the arm doesn’t return even when it has come near the
label on the record.

ALIGNMENT OF THE CIRCUIT

FREQUENCY MULTIPLE ADJUSTMENT
(Refer to Figures 7—1 and 8-3) 6-bed wave timeConnect the oscilloscope to pins 25 (GND) and 27 Adjust the semi-variable resistor (VR1) so that good waveform is indicated in Figure 7—1.

DRIVE CIRCUIT ADJUSTMENT

1. HALL DEVICE (Refer to Figures 7—2 and 8—2)ET, OS VILE
2. Connect the oscilloscope to the pins 25 (GND) 0.13V and 28 (+). NWY\WIWI)Y SSO VR1 ‘Frequency Multiple Circuit Adjust.
3. Adjust the semi-variable resistor (VR1104) so that Bed! mover ‘ VR2 ‘Turntable Speed Adjust (83—1/3rpm) good waveform indicated in Figure 7-2.

COIL CURRENT
(Refer to Figures 7—3 and 8—2) VR101: Stroboscope Frequency Adjust

1. Connect the oscilloscope to the pins 25 (GND) Vs -V=0.08V (EP) and 28 (+).
2. Adjust the semi-variable resistors (VR6 and 7) so that a good waveform is indicated in Figure 7-3.

ADJUSTMENT OF THE MOTOR’S ROTATION

(Refer to Figures 8-1 and 8—2) (Refer to Figure 8—2) The revolutional speed of the turntable minutely varies according to 1.

Connect the frequency counter to the base of the transistor to the hour during the day, therefore, take the following process- (Q101) and ground. | duress to obtain an exact speed.

Adjust the semi-variable resistor (VR101) so that the Turn the speed fine adjustment knob clockwise or anti-frequency counter indicates 120 Hz.

clockwise to adjust so that the stripe pattern of a stroboscope provided at the platter looks stationary.

When the stripe pattern is moving in the turning direction of the platter, this shows that the rotational speed of the turntable is faster than specified. In this case, adjust it by turning the speed fine adjustment knob toward ‘s’.

when the stripe pattern is moving against the turning direction of the platter this shows that the turntable rotates slower than as specified. In such a case, adjust it by turning the speed fine adjustment knob toward ‘f’. When the servo-control! P.W. board or other electrical parts MEd. are replaced for repairing, adjust the turntable speed in the following manner.

Set the speed fine adjustment knobs (VR4, VR5) to the central position. Adjust the semi-variable resistors (VR2, VR3) so that the stripe pattern of a stroboscope provided at the platter looks like stationary. VR2 wees en oe8 For 33-1/3 r.p.m. Adjust VRS 4444.04 For 45 r.p.m. Adjust (Specifications or wiring diagrams of this model are subject to change for improvement without prior notice.)

REPLACEMENT PARTS LIST

HOW TO ORDER REPLACEMENT PARTS”
To have your order filled promptly and correctly, please furnish the following information.

1. MODEL NUMBER
2. PART NO.
3. REF. NO.
4. DESCRIPTION

PARTS LIST

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