Leak TL50 Plus Owners Manual

Page 1

IL IE AIK

TL/ 50 PLUS POWER AMPLIFIER

INSTALLATION, OPERATION 5: MAINTENANCE

l. The TL/SO Plus may be fed from Leak
"Varislope III" and Point One Plus" pre-
amplifiers, or from any other suitable
source. An input of 125mV r.m.s. will

give a power output of 50 watts.

Leak pre-amplifiers are supplied with a
multiple connecting cable terminating in
an octal plug which fits the socket on the
'IL/SO Plus marked PRE-AMP" and auto-
matically makes the input connection. In
this case the input "GAIN" control should
be turned fully clockwise.

When a Leak pre-amplifier is not used the
input connections should be taken via a
screened co-axial cable to the plug fitting
the socket marked "INPUT and the GAIN"
control adjusted to suit the signal level.

2. Check that all tubes are correctly
seated in their holders and that the mark-
ings on the tubes correspond with those on
the chassis adjacent to the holders. The
amplifier will work equally well with any
of the alternative tubes listed on the
chassis.

3. The amplifier should stand on its base
in a well-ventilated position. If placed
in a case or cabinet, ventilation must be
provided. Four separate fixing feet, with
screws, are provided. These feet raise the
chassis from the mounting surlace and assist
ventilation.

4. The mains transformer is tapped for
voltages of 100, 108, 116 and 124- and the
voltage selector plug on top of the mains
transformer should be set appropriately.

5. There is a female receptacle supplied
with an AC power cord attached. This
should be plugged into the rear of the.
amplifier marked "AC mm".

6. In order that the amplifier may be
remotely controlled, we have provided two
terminals marked SWITCH" underneath the
mains transformer (see "Under Chassis"
drawing). The amplifier will not work
unless these terminals are electrically
joined. When the amplifier leaves our
factory a twin cord is joined to these
terminals; the cord passes through the
grommet marked "SWITCH CARE" and is
terminated in a flat female receptacle
which normally is plugged into the rear of
the Leak pre-amplifier marked "SWIIUI".
This enables you to switch the 'IL/SO Plus

Power Amplifier by using the switch incorp-
orated in the volume control of the Leak
pre-amplifier. If a Leak pre-amplificr is
not used, you may replace the flat female
receptacle with a switch.

7. A double socket marked AC UJ'I'LETS" is
fitted as a convenient source of power
supply for phonograph motors, self-powered
radio tuners, etc. The power taken from
this socket should be limited to 100 watts
or thereabouts. This socket is not
controlled by the amplifier switch or fuse.

B. The amplifier can be grounded by use

of the third terminal on the removable plug
portion of the AC POWER" connector. This
terminal is the one furthest away from the
guide key and its corresponding terminal on
the connector on the amplifier is marked on
the chassis by the symbol tifl . The ground
can be made to the water system or the steel
conduit casing the house wiring. No other
ground connections should be made elsewhere,
particularly when a pre-amplifier is used.

9. The loudspeaker should be connected by
a twisted pair of wires to the terminals
marked LGJDSPEAIG'TR. The loudspeaker
should not be grounded.

Do not operate the amplifier without a
loudspeaker attached.

The selector plug on the top of the output
transformer should be placed in the sockets
to give the nearest match to the advertised
impedance of the loudspeaker being used.

GENERAL NOTES (N MAINTENANCE

The circuit diagram provides a qualified
engineer with all information required for
servicing. However, the following points
may be of interest:

(a) The TL/SO Plus does not depend upon
the output tubes being a matched pair to
give the stated performance, and if one
output tube fails it is not necessary to
replace both.

(h) Should it ever be necessary to replace
the reservoir capacitor C14 note that it
must be of a type capable of handling at
least 200m ripple current. The C14 fitted
has a high margin of safety, being capable
of handling 240M.

Made in England by H. I. LEAK & CO. LTD.

BRUNEL ROAD

WESTWAY FACTORY ESTATE

LONDON. W.3

Distributed solely in the U.S.A. by

BRITISH INDUSTRIES CORP.

Printed in Enuland

80 SHORE ROAD

PORT WASHINGTON, N.Y.