Manley Reference User Manual

MANLEY

LABORATORIES, INC.

OWNER'S MANUAL

THE REFERENCE

PREAMPLIFIER

MANLEY LABORATORIES, INC.

13880 MAGNOLIA AVE.

CHINO, CA. 91710
TEL: [phone]
FAX: [phone]

email: [e-mail]

http://www.manleylabs.com

CONTENTS

SECTION PAGE

INTRODUCTION 3

MAINS CONNECTIONS 4

CONNECTING YOUR PREAMPLIFIER 5

REAR PANEL 6

FRONT PANEL 7

FRONT PANEL SPECIAL FUNCTIONS (SOFT-START, phono) 8

BALANCED or UNBALANCED ? 9

TOP VIEW (Tube Locations, Fuses) 10

OPERATIONAL NOTES 11

TROUBLESHOOTING 12

SPECIFICATIONS 14

WARRANTY 15

WARRANTY REGISTRATION 16

INTRODUCTION

THANK 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 metal­film 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.

3

MAINS CONNECTIONS

Your preamplifier has been factory set to the correct mains voltage for your country. The
voltage setting is marked on the serial badge, located on the rear panel. Check that this com­plies with your local supply.

Export units for certain markets have a moulded mains plug fitted to comply with local require­ments. If your unit does not have a plug fitted the coloured wires should be connected to the
appropriate plug terminals in accordance with the following code.

GREEN/YELLOW EARTH terminal
BLUE NEUTRAL terminal
BROWN LIVE terminal

As the colours of the wires in the mains lead may not correspond with the coloured marking
identifying the terminals in your plug proceed as follows;

The wire which is coloured GREEN/YELLOW must be connected to the terminal in the plug
which is marked by the letter E or by the safety earth symbol or coloured GREEN or GREEN
and YELLOW.

The wire which is coloured BLUE must be connected to the terminal in the plug which is
marked by the letter N or coloured BLACK.

The wire which is coloured BROWN must be connected to the terminal in the plug which is
marked by the letter L or coloured RED.

DO NOT CONNECT/SWITCH ON THE MAINS SUPPLY UNTIL ALL OTHER CON­NECTIONS HAVE BEEN MADE.

4

CONNECTING YOUR PREAMPLIFIER

1. Please refer to the following page for an illustration of the back of the preamplifier.

2. There are two main outputs per channel. These get connected to the power amplifier(s) when
all ON/OFF switches are off (including the amps). One pair is standard RCA unbalanced line
outputs and the other pair are balanced XLR outputs. Use either (the unbalanced RCA's are
more"purist")(The Balanced outputs have one more stage of amplification). The Balanced
outputs are the best choice to drive a second set of amplifiers in a different room. Use both
outputs for some bi-amp applications.

3. Use the RECORD OUTs to send to your tape recorder inputs. This output is derived from the
Input Select Switches. This output is buffered (another tube is used to isolate this jack) to
preserve signal integrity regardless of the load. We can recommend that one have the tape
feed plugged into the REC OUT only when actually recording especially if there are kids or
a spouse that may use the system with less respect. The main concern is selecting "TAPE"
when the tape deck is also reflecting that input and a little gain exists. If you switch to "tape"
at the preamp, when recording or if the deck is in "input" or "source" expect the howl of
feedback. Unfortunately "purist", "foolproof" and "comprehensive" are mutually exclusive.
This is normal for purist preamps that don't have a "tape monitor" switch or "record select"
switch. One eliminates extra "stuff" that might degrade the main signal path.

4. Normal line inputs are found on RCA jack inputs and can be connected to any line level
sources such as, tuners or tape decks. Each of the RCA jacks are clearly labelled as to a
typical function. Each input is for all intents functionally and electronically the same except
for the phono inputs and CD inputs. The CD inputs have 6 dB less gain because CD players
and DACs tend to have hot outputs. The phono inputs have much more gain and a frequency
response that the RIAA "curve" specifies. Connect you turntable to the moving magnet or
moving coil inputs depending on your cartridge. Don't forget to attach the turntable ground
wire to the gold ground post located between the moving magnet jacks. If you use an external
equalized phono preamp connect it to the line input of your choice.

5. There is one pair of balanced inputs with 3 pin XLR female jacks. Some newer components
allows the choice of balanced or unbalanced connection. We recommend careful listening
to determine whether the balanced or unbalanced connection is preferable. It is usually
subtle and depends on several factors. Some professional tape machines only have balanced
outputs and these would be the appropriate inputs. You may find that you want to reduce the
output level on a pro (+4dBm) tape machine to "match" your other (-10dBm) inputs.

6. Connect the two power supply cables from the power supply unit to the preamplifier.
Remember, AC power should be OFF at the power supply for for at least 5 minutes.

7. On the power supply back panel is a standard IEC mains connector. This should be connected
to a standard mains outlet with the supplied cable. This unit has been hard-wired for the
mains voltage in your country. Are you ready for music?

8. Power up the preamplifier FIRST at the POWER SUPPLY ON/OFF switch (LED glows)
and allow it to settle for a minimum of 30 seconds before powering up your amplifiers. Select
a source, turn up the volume and sit down (or dance!). Turn off your preamplifier and source
components LAST when powering down a system. (Amps on last and first off) This prevents
amplification of turn-on transients and other noises when powering up or turning a system
off and ultimately protects the speakers.

5