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CONTENTSINTRODUCTION3
MAINS CONNECTIONS4
CONNECTING YOUR PREAMPLIFIER5
REAR PANEL6
FRONT PANEL7
FRONT PANEL SPECIAL FUNCTIONS (SOFT-START, phono)8
BALANCED or UNBALANCED ?9
TOP VIEW(Tube Locations, Fuses)10
OPERATIONAL NOTES11
TROUBLESHOOTING12
SPECIFICATIONS14
WARRANTY15
WARRANTY REGISTRATION16 SECTION PAGE
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INTRODUCTIONTHANK YOU!...
for choosing the Manley Laboratories "The Reference Preamplifier". Designed by David Manley, the
Reference Preamplifier uses the best available parts with the shortest, cleanest, active signal path
possible. This Preamp is the most expensive and high quality in our range of preamps. Manley is very
highly regarded for power amplifiers and pro recording equiment but often forgotten for preamps.
Why? Simply never had a review of one. Nothing published, no ads and no USA showrooms. It is
true that essentially the same circuits have received top honors and reviews in the Reference D to A
converter and some of the professional recording products. Our complements for discovering a real
winner that the media has never even tried.
To complement our best sounding line driver to date, we used every technique to preserve
separation and audio integrity. We used a 24 position gold contact sealed Grayhill switch with metal-
film 1% 1/2 watt resistors for a superior audio attenuator. The Input Select Switches are separate as
are the mirror-image gold plated elastically suspended printed circuit boards. The RECORD output is
buffered to prevent loading. The tube regulated power supply is in a separate chassis (as you know) to
prevent noise and hum. The elegant front panel finish is a high purity plated gold that complements
the electronics both visually and in its long lasting outstanding quality.
We build two versions - one with line inputs only and the second with a unique fully
differential floating phono preamp stage. This manual is intended for both products - so if you have
the line version just skip over sections that deal with phono. Please take a few moments to read
through this manual, there may be features and information about this preamplifier which you should
familiarise yourself with.
Thank you again, and please enjoy!
GENERAL NOTES
IMPORTANT SPECIAL NOTES - READ THIS - DO THIS
The circuit boards are designed to be mechanically vibration isolated. It uses 4 elastic rings that
suspend the printed circuit boards. For shipping, the factory screws down the circuit boards to prevent
shipping damage - These need to be unscrewed. Without taking off any top or bottom perforated cover
- look at the bottom of the preamp. You should see 4 small silver colored Phillips screws. These are
towards the center and not along the edge. Remove these 4 screws ! The printed circuit will spring
up about 1/2 inch and rest. This helps prevent mechanical vibrations from affecting the sensitive
tubes. Save the screws (4-40 size). You should re-screw them (gotta open the top) for shipping
LOCATION & VENTILATION
The Reference Preamplifier must be installed in a stable location with ample ventilation. It is
recommended, if this unit is rack mounted, that you allow enough clearance on the top and bottom of
the preamp such that a constant flow of air can flow through the ventilation slots. This is especially
true for the phono version which uses 12 tubes internally. We also recommend that the preamplifier be
placed at least 10 inches away from the power amplifier(s) to reduce hum pick-up. It should also not
be placed mounted on a speaker cabinet because vibrations can shorten tube life, cause microphonics
and degrade performance. As with any electrical equipment, this preamplifier should not be used near
water or moisture. It is not designed for outdoor use.
SERVICING
The user should not attempt to service the preamplifier beyond that described in the owner's manual.
Refer all servicing other than tube replacement to Manley Laboratories.
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