Dual 622 Service Manual

Service
Manual
Technical Data
Currant
Line voltage
Drive
Power
input
Power consumption
Time from start to
rated speed
Platter
Platter speed
Pitch control
Speed
control
(monitoring)
Sensitivity of
the illuminated strobe
(for 0.1 %
speed
deviation)
Total
wow and
flutter
(according to DIN
45507)
Rumble
(according to
DIN
45500)
Tonearm
Effective
length of tonearm
Offset angle
Tangential tracking
error
Tonearm
bearing friction
(related to
stylus tip)
Stylus
pressure
Cartridges
Weight
Dual
622
Edition
January 1980
AC 50 to 60
Hz
110 to
125V,
220t0
240V
electronically-controlled
direct-drive system, Dual EDS 500
Motor at playing
operation approximately 2 watts <50
mW
220 V 50 Hz:
at start 35 mA
110 V60 Hz: at Start 65 mA
at play 15 mA at play
approximately 25 mA
2- 2.5s at 33 1/3 rpm
non-magnetic, 1.4 kg, 304 mm diameter
33 1/3 and 45 rpm, electronically adjustable
Separate for both speeds,
each adjustable by means of
variable resistor, with
calibration scale;
range of regulation: 10%
with illuminated
stroboscope for
platter speeds 33 1/3 and 45
rpm, adjustable to 50
or 60 Hz
6 division markings per
minute at 50 Hz,
7.2 division markings per minute at 60
Hz,
(German Industry Standard) ±
0.05 %
WRMS ±
0.03
%
Unweighted: 50 dB
Weighted:
75
dB
Torsionally rigid
tubular aluminum
tonearm in low-friction
four-point gimbal
suspension
221 mm
24 0 4'
0.16
0 /cm
vertical <
0.07 mN
(0.007 g)
horizontal <
0.15 mN
(0.0159)
from 0 to 30
mN (0 to 3 g)
infinitely variable with 1
mN- (1/109)
calibrations from 0 to 15 mN
(0 to
1.59)
operable from
2.5
mN (0.259)
stylus pressure up.
with 1/2 inch
screw-type
attachment. These can be fitted
with the special
accessories no. 262 186
which
can be obteined from trade dealers.
ca. 5.4 kg Dimensions and
Cutout Required refer to
Installation I nstructions,.
Download from www.dual.de
Not for commerical use

Dual 622 Specifications

General

Brand	Dual
Model	622
Category	Speakers
Language	English

Summary

Technical Data

General Specifications

Covers current, voltage, drive type, power input, and consumption details.

Speed and Performance Specs

Details time to speed, platter specs, speed control, and wow/flutter.

Tonearm and Cartridge Details

Encompasses tonearm geometry, bearing friction, stylus pressure, and cartridge compatibility.

Motor Electronics and Mechanics Repair

Motor Electronics Replacement

Step-by-step guide for replacing motor electronic components and testing.

Motor Mechanics Replacement

Procedure for replacing the motor unit and associated mechanical parts.

Speed Adjustment and Control

Setting Nominal Speeds

Instructions for adjusting 33 1/3 rpm and 45 rpm speeds using controls.

Pitch Control Operation

Explains the variable speed control for fine-tuning pitch and motor speed.

78 RPM Speed Changeover

How to convert the unit to operate at a nominal speed of 78 rpm.

Stroboscope Usage

Guide on using the stroboscope for accurate speed checking and potential causes of apparent movement.

Tonearm and Suspension System

Tonearm Removal Procedures

Details on removing the tonearm assembly and its bearing for maintenance or replacement.

Tonearm Bearing Adjustment

Steps for correctly adjusting the tonearm's horizontal and vertical bearings for minimal play.

1/2 Inch Cartridge Fitting

Instructions for fitting a 1/2 inch standard mount cartridge using a conversion kit.

Anti-skating Device Function

Explanation of the anti-skating mechanism and its adjustment for compensating skating force.

Cue Control and Tonearm Automation

Cue Control Operation

How to use the lever to raise and lower the tonearm during playback.

Cue Control Plate Replacement

Step-by-step instructions for replacing the cue control plate assembly.

Automatic Tonearm Movement

Details on how control cams initiate automatic tonearm movement for record playback.

Muting Switch Function

Purpose and adjustment of the muting switch to prevent noise during automatic operation.

Operation Modes and Controls

Starting Playback

Sequence of operations for initiating playback via manual or automatic start.

Continuous Play Function

How to engage continuous playback and its behavior after a record finishes.

Stopping and Shut-off Procedures

How to stop the unit and the automatic shut-off mechanism after playback.

Fine Adjustments and Troubleshooting

Tonearm Set-down Adjustment

How to adjust the tonearm's set-down point on the record using an eccentric bolt.

Shut-off Point Adjustment

Procedure for adjusting the automatic shut-off trigger point on the segment.

Tonearm Lifting Height Setting

Steps to set the correct vertical lifting height for the tonearm.

Power Switch Adjustment

How to adjust the power switch slide for proper play.

Common Defects and Remedies

Troubleshooting guide for common issues like tonearm set-down or vertical movement problems.

Replacement Parts List

Component Part Numbers

Comprehensive list of part numbers, quantities, and descriptions for unit components.

Lubricating Instructions

Lubrication Points and Recommendations

Guidance on lubricating bearing and friction points, recommending original lubricants.