Garrard rp 2 owners manual

Page 1

July 1970

RP2/l

DISK REPRODUCERS RP2/l AND RPZ/IB

General Description

Disk reproducer RPZ/l is a twin-turntable
reproducing desk which can be used to replay
coarse-groove pressings and disks up to 13 inches
in diameter at 78 r.p.m., or for fine-groove mono
at either 33} r.p.m. or 45 r.p.m. Pickup cartridges
of the turnover type are used, mounted on pickup
arms RPZB/l to which are coupled optical pickup
position indicators on the turntable units RPZC/l.
These units are built around the Garrard trans-
scription motor Type 301, and incorporate quick-
starting arrangements.

A general view of the reproducer is given in
Fig. l. The equipment is housed in a wooden
desk-type cabinet CT3/3, the upper surface of
which is filled by the two turntable units; a hinged
lid is fitted which covers both units. A script-rest
is hinged to the lid along its upper edge; the lower
edge is coupled to the lid stay in such a manner
that the rest is thrust forward to a convenient
position when the lid is raised.

The sloping front of the cabinet is filled by a
desk panel PAS/21A, hinged at its lower edge so
that it can be opened (as shown in Fig. 2) for
maintenance purposes. The panel carries twin sets
of controls and indicating devices, headphones
jacks, two amplifiers AMIG/l (one for each
turntable unit), and a combining unit RPZA/l.

A shelf inside the cabinet, level with the bottom

of the desk panel, supports the power supply and
control unit RPZA/Z.

The lower part of the front of the cabinet is a
removable panel, carrying the double-pole mains
isolator of the reproducer near its upper left-hand
corner. On the inner surface of the panel are
mounted two mains outlets. One of these, a
standard 3-pin S-amp type, supplies the RPZA/Z;
the other, a three-pin D. & S. type, supplies the
second desk when two or more desks are installed
together. This second mains outlet is not controlled
by the mains isolator. The reproducer is connected

to the main . supply and earth by a three-way
flexible lead.

RPZ/l

Differences in Type RP2/lB

The RP2/lB enables stereo as well as mono
fine-groove recordings to be played monophoni-
cally. The two turntable units have modified
pickup arms fitted with pickup cartridges dilierent
from those used in the RP2/l. A twin-channel
pickup amplifier, Type AM16/6, is included to
compensate for the lowéer sensitivity of the pickup
cartridges.

The pickup cartridges are not suitable for

' playing 78 r...pm disks and the turntable units

have been made inoperative at this speed.

As well as the added AM16/6 amplifier, the
RP2/1B includes the following units modified
relative to those in the RP2/l:

Two RPZB/ 1B pickup arms,

Two RP2C/ 1B turntable units,

One RP2A/2A power supply and control unit,
One PAS/21B desk panel,

Two AM16/ 1A reproducing amplifiers,

One RPZA/ IA combining unit.

Rubber pads are added to the CT 3/3 cabinet to
serve as supports for the turntable units.

Turntable Unit RP2C/l (Figs. 1 to 6)

The turntable unit is built on a 3/16-inch alu-
minium alloy motor plate on which the transcription
motor is mounted. The motor is modified by the
drilling of a number of additional holes and the
enlargement of some existing ones to enable
various components of the unit to be mounted
on it, as well as on the motor plate.

The unit is supported resiliently on plywood
corner pieces of the cabinet CT3/3 by four conical
springs (item 29) attached to studs on the underside
of the motor plate. These studs project downward
thrOugh holes in the corner pieces and have
extensions which form legs (30) on which the
turntable unit can he stood when necessary.

To provide quick starting, a stroboscopic disk
(10) on which the record is placed is supported a
little above the turntable, and the turntable (already
rotating) can be raised when required so that it
lifts and turns the stroboscopic disk and record.

Page 2

RP2/l

In the RPZC/l. this arrangement is motor~operated.
The motor employed (33) is a Plessey tuning
motor Type 2521/4, referred to as the control
motor in this Instruction. The control motor
and some of the circuit components associated
with it are mounted on the control motor bracket
(34) attached to the underside of the motor plate.
A separate control plate (7) to the right of the
motor plate carries the Stop/Starr key (6) by which
the control motor is operated. When the key- is

thrown, the control motor is started; it is stopped, '

after .a length of run sufficient to complete the
raising or lowering of the turntable, by one of the
two cam-operated microswitches (26, 28) on the
control motor bracket.

Apart from the quick-starting arrangements,
the turntable motor is operated by means of its
own Oil/Of, 78/45/33 and line speed adjustment
controls. A switch wafer (38) is ganged to the
78/45/33}. control to operate pilot lamps in a lamp
housing and, in conjunction with a microswitch in
the pickup head, to Operate an alarm circuit if an
attempt is made to run the equipment with an
inappropriate combination of turntable speed and
pickup stylus. Fine adjustment of the turntable
speed is facilitated by the stroboscope disk (10)
which is pierced with a series of holes for each of
the three standard speeds, and illuminated by a
neon lamp (G.E.C. Button Tuneon) supported in
an S.E.S. holder (3'!) fixed in the motor plate near
the front of the unit, below the edge of the disk.
The neon lamp is supplied from the 50-82 a.c.
mains (via a resistance-capacitance network in the
power supply and control unit).

The pickup position indicator employs an optical
display system. A glass slide, supported by .a
sealeholder (31), is attached to the lower end of the
pickup arm spindle. The image of a moving scale
is projected from this arrangement onto a frosted
panel (1) beside the turntable Speed indicators.
The projector lamp (39) is a G.E.C. 12-volt, 24-watt
type, Cat. F/3.

A sloping-fronted sheet-metal box (the lamp
housing) extends across the greater part of the
width of the motor plate, to the rear of the turn-
table. It is held by two screws through its upper
surface, tapped into the ends of pillars (8) mounted
on the motor plate. On the sloping front of the
housing, over suitable apertures, is fastened an
index frame containing the frosted perspex panel
('1) on which is displayed the projected image of the
moving glass slide of the pickup position indicator.

July 1970

The index frame also contains three smaller panels
(2) inscribed 33, 45 and 78, and a further small
panel (3) coloured red. The four small panels are
all illuminated at appropriate times by pilot lamps
(40); the lamps behind the numbered panels are
operated by the switch wafer (38) ganged to the
78/45/32; control of the motor unit, and the lamp
behind the red panel by the auxiliary contacts of the
fader associated with the turntable unit. The faders
(Type PN/12M1) are mounted on the desk panel
PA8/21A. The supply to the pilot lamps behind the
numbered panels and to the projector lamp of the
pickup position indicator is controlled by a micro-
switch (35) on .a bracket mounted on the underside
of the motor unit and actuated by one of the
moving parts of the turntable motor On/ 017 control.
The supply to the lamps is made when the control
is set to On. The function of the switch when the
control is set to 013' is described later.

The lamp housing covers the base of the pickup
arm RPZB/ 1, and is pierced with an inverted
L-shaped slot to enable the housing to be fitted
and removed, and the arm rotated about its pivot.
A pickup raise/lower mechanism is fitted at the
right-hand end of the housing, consisting of a
spindle, stipported in a spindle housing, carrying at
one end a knurled hand wheel (4) and at the other
an eccentrically mounted ballrace which, over part
of the cycle of rotation of the spindle, presses on a
plate (44) attached to the overhanging rear end of
the pickup arm and thus raises the stylus from the
turntable. The handwheel is fitted with a weight,
so that the mechanism has a top dead centre
position oecuring between the Up and Down
conditions of the pickup arm. A stop is fitted which
gives a definite location of the handwheel for the
Up condition.

A pickup rest of thick perspex and a post
providing stowage for a 45~r.p.m. adaptor (25) are
mounted on the upper surface of the motor plate.

A circuit diagram of the RPZC/l is given in
Fig. 6. The connections to the unit are via a
flexible lead terminating in a 33-way male Painton
connector (21) Type 313272 which mates with one
of a pair of corresponding female connectors Type
311531 on the chassis of the power supply and
control unit. 0n the turntable unit, the lead
terminates at three tag strips and a terminal block
on a tag board (36) mounted on brackets attached
to the underside of the motor unit, near the front
edge. The terminal block carries the mains connec-
tions to the turntable motor and the stroboscope