Page 2
INTRODUCTION!THANK YOU!...
for choosing the Manley DIRECT INPUT 50/50 Amplifier. Designed by David Manley, the Manley DIRECT
INPUT 50/50 Amplifier uses only the best available components, with the shortest and cleanest signal path
possible, and with the use of our own in-house CNC machine shop we can provide you with a amplifier that looks
as good as it sounds.
The circuit and the components used have been chosen carefully after years of development and refinement for
reliability, constancy and most importanly, musical, accurate, and emotional delivery of the sound. The circuit
topology is similar to other designs in the MANLEY range. This amplifier is configured for the more powerful
tetrode operation mode with a separate regulated screen supply which allows a wider range of EL34s to be used as
the screens are run at safer lower and constant voltages . We emphasize big, beefy resevoir capacitors in the high
voltage supplies giving plenty of instant energy for dynamic performance of transient peaks and bass performance
which often exceeds that of rival solid-state amplifiers. We run high voltages on the plates of the output tubes and
are thus able to run them at lower current which will result in longer life for the output tubes. Each output tube has
its own bias adjust, and the procedure for adjusting each tube's current draw is described in this manual. The
multi-sectioned output transformer has been factory set for an optimum 5 ohm load which will drive most
speakers comfortably. This amplifier with its built in selector switch, record output, and precision stepped
attenuator becomes the efficient and compact heart of a system which should bring you years of pleasure.
Thank you again, and please enjoy!
GENERAL NOTES
LOCATION & VENTILATION
The Manley DIRECT INPUT 50/50 Amplifier must be installed in a stable location with ample ventilation.
Allow a minimum of 2 inches of clearance on the top and sides of the amplifiers, such that a constant flow of air
can flow. Do not place amplifiers directly on high pile carpet or any other surface that will block the ventilation
vents underneath the amplifiers. If you have small children or pets, you should consider placing the amplifiers out
of reach to prevent damage to the amplifier or damage to your small children or pets by the amplifier as the tubes
do get hot during operation.
WATER & MOISTURE
As with any electrical equipment, these amplifiers should not be used near water or moisture. If liquid enters the
amplifier, it must be immediately returned to your dealer for servicing.
SERVICING
The user should not attempt to service the amplifier beyond that described in the owner's manual. Refer all
servicing other than biasing and tube replacement to Manley Laboratories
SPECIAL NOTES
Tubes may become loose during transit. Straighten and press down each tube before plugging the amplifier into
the mains socket. Furthermore, do not touch the tubes after the amplifier has been switched on, as the tubes
become very hot during operation and should only be handled after the power has been turned off and the tubes
have cooled.
WARNING!
TO PREVENT THE RISK OF ELECTRIC SHOCK
DO NOT OPEN THE CABINET
REFER SERVICING TO
QUALIFIED PERSONEL
