Manley Stingray User Manual

MANLEY

LABORATORIES, INC.

OWNER'S MANUAL

MANLEY STINGRAY

INTEGRATED AMPLIFIER

MANLEY LABORATORIES, INC.

Web site: http://www.manleylabs.com

13880 MAGNOLIA AVE.

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

email: [e-mail]

REV. 11-2-2005

CONTENTS

SECTION PAGE

INTRODUCTION 3

MAINS CONNECTIONS 4

OPERATIONAL NOTES 5

CONNECTING YOUR STINGRAY 6&7

SIMPLE TROUBLESHOOTING 8

FRONT PANEL, LAMP, BACK PANEL 9

TUBE LOCATIONS 10

SIDE PANELS 11,12&13

OPTIMIZING YOUR SOUND SYSTEM 14&15

TUBE FAQ 16&17

REPLACING TUBES & SETTING BIAS 18

CREDITS 19

SPECIFICATIONS 20

WARRANTY 21

WARRANTY REGISTRATION 22

2

INTRODUCTION

THANK YOU!...

for choosing the Manley STINGRAY integrated amplifier for your loudspeaker driving requirements. You have
possibly chosen this product because you auditioned it in a store or heard it at a hifi show and were impressed with
the sound. It may have been the right combination of price, power, features and styling for you. It may have been
because you know the Manley Labs reputation for quality, reliability, and integrity. If any or all of these were the
reasons, you made a good choice and for that, we thank you.

The STINGRAY design evolved from our older Manley 50 Watt Monoblocks which were melded into a stereo
chassis with basically a passive preamp. The 50 Watt Monoblocks had evolved from the Manley 35W monos and
before that, the famous Tiny Triodes before that. (Yes, there were MANLEY Tiny Triodes too in the early 1990's!)
Even harkening back to the mid-1980's, the earliest Manley designs were EL84 based, and Hutch still has one of
these British-built single input with passive volume control stereo integrated EL84 amps on his test bench 20 years
later. All of these little EL84 based amps featured sweet highs and three dimensional staging and imaging. But
before it always seemed that they were a little whimpy in the bass. Why? Shouldn't be the tubes' fault.

In 1997 EveAnna Manley set out to change that history. We first attacked and refined all performance aspects of
the output transformers. After calculations and experiments, measuring and listening, we got our bass back (in big
ballsy spades) with the new output transformer design, still used today. The advantages of a passive preamp are
well known - near absolute transparency, no added noise and extreme signal path simplicity. The low amount of
global feedback used in the Stingray which has one result of increased input sensitivity lends itself well to a passive
front end. Then Paul Fargo stepped in to revise our older driver stage. This was the final icing on the Stingray audio
circuit cake, and since 1997 the basic audio flow has remained unchanged. Minor refinements to the power supply
and a few enhancements to the audio path have been over the years to the Stingray design, but overall it has been a
stable product, and one of our best sellers. In 2005 we responded to numerous customers' requests to add even
more preamp and switching features and at this point, we would consider it as crammed chock full of features and
parts as we can muster in this chassis. Enjoy!

Please read over this entertaining and enjoyable owner's manual carefully as it contains information essential to the
proper operation and maximum enjoyment of this fine instrument. Many of the remarks contained herein are
especially pertinent if the STINGRAY is to be your first long-term encounter with a vacuum tube power amplifier.
Thank you again, and please enjoy your new STINGRAY! (and the clever Owner's Manual.)

UNPACKING: Unpack the amplifier carefully by removing all the custom foam packing material and make sure
that all supplied accessories are present. Carefully examine all items for any possibility of shipping damage. All of
the tubes are already installed and should have survived the journey protected by their very own grey foam insert.
They should be standing at attention in their sockets, and should show no signs of distress such as chipped glass,
loose internal components or obvious breakage. If the amplifier is damaged or fails to operate, notify the shipper or
your dealer or us or your local authorities immediately. Or if you suspect The Shipping People threw it off the
airplane and onto your front porch whilst flying overhead at 30,000 feet, notify the shipping company without
delay and complain to them as we only guarantee this unit to be able to survive a drop of 23,487 feet or less.

Your STINGRAY was packed by Manny Q. with extreme love and each box includes the following components
and accessories:
a) 1 each, 6 foot IEC 3-conductor power cable (that you will probably replace with an expensive audiophile cord anyway.)
b) 1 each, Owner’s Manual (that we hope you will keep reading.)
c) 1 each, cheapo but perfectly functional METER for setting your bias

It is prudent to retain the shipping materials for future use, as they are custom-formed for the amplifier and
will greatly minimize the chance of shipping-related damage should you ever need to put your precious
STINGRAY in the careless hands of The Shipping People again. We have heard that certain rodents might
enjoy munching on the packing foam. We are sorry to report that we do not warranty the packing foam
against attack by mice, rats, or other hungry critters, hungry children, hungry neighbors, etc. Try glue traps
or spring-traps loaded with peanut butter to eliminate these unwelcome freeloaders from your property.

3

MAINS CONNECTIONS

Your STINGRAY has been factory set to the correct mains voltage for your country. (Well, that is what we

intended to do when we knew where it would be initially shipped.) The mains voltage that we built this STIN­GRAY to operate with is marked on the serial badge, located on the rear of the chassis. Check that this complies
with what comes out of your wall.

There is no voltage changeover switch! The power transformer's primaries must be either wired in parallel for 120v
operation or in series for 230v or 240v countries so be sure to check the sticker and the serial number voltage
indication for proper mains voltage. Failure to properly comply with mains voltage requirements can cause
extensive damage to the system, which of course would not be covered by the warranty. If you relocate from, say,
a 120v country to a 240v country, you will need us to rewire the Stingray's power transformer for you or get
instructions from us to perform this operation if you happen to be as good at soldering as we are, or know someone
who is. We are not telling you how to do this in this Owner's Manual because you need to pass a battery of tests for
us before we will let you play with soldering inside the amplifier. Contact [e-mail] for more
details. Note: Stingrays shipped to Japan use a special 100v power transformer.

The MAINS FUSE may be checked by first disconnecting the IEC mains cord from the power supply’s power inlet
plug. Then gently push the light grey fuseholder retainer clip located next to the IEC power socket. The fuse and
cap should spring outward toward your fingers. The fixed silver springy looking thing is NOT the fuse. Leave that
alone. The fuse is a glass or white ceramic thing with silver end-caps. Inspect the mains fuse for the proper rating;
change if necessary. Refer to the fuse rating chart in the specifications section of this manual. If you do not know
what a blown fuse looks like, you may measure for continuity across the fuse ends. If your meter reads “OL” when
you measure across the fuse, that means “Open Leads” and that would mean the fuse is blown. A blown fuse
usually indicates A Very Bad Thing occurred. If this has happened to you, try to figure out why it may have
happened. (Using a Fast Blow fuse when we have specified a SLO-BLO fuse is one reason, output tubes running
away into never-never land are another reason.) If you have no idea why a fuse might have just blown on its own,
you might want to consult with Manley Labs or your dealer for further advice as Something Very Bad might have
occured, like the power transformer might have decided to retire early.

One way this could happen is by running the wrong mains voltage into the unit. Be sure not to do that.

If you live in a strange place...

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 OR SWITCH ON THE MAINS SUPPLY UNTIL ALL OTHER
CONNECTIONS HAVE BEEN MADE. (...or else...)

4

OPERATIONAL NOTES

PREPARATION FOR INSTALLATION

Budget a suitable space in which to place the amplifier and associated interconnect and mains power cable. This
space should be free of strong external magnetic and RF fields, and reasonably removed from strong loudspeaker­generated acoustical fields. This space should also be free of excessive heat or dust and large enough to permit easy
flow of cool air to the top, bottom and sides of the amps. Do not connect the STINGRAY to the AC mains until the
other interconnections and items outlined below have been completed.

Keep other associated equipment some distance away from the amplifiers. This will help keep airflow unrestricted,
and cut down interference from radiated magnetic hum fields that can eminate from certain power supplies. Notice
that the output tube’s glass envelopes are capable of reaching high temperatures, depending on operating
circumstances. As with other equipment of this sort, it is best to keep the STINGRAY out of reach of pets or
children, or be careful to keep children and pets away from the amplifier when in use. Or train them. Not too hard.

People sometimes ask us why we don't supply a cage to protect children and pets from the scary exposed tubes. I
always answer that I grew up with a tube receiver and survived ok and a cage would look ugly. The only physical
harm that came to any of my family growing up from that tube receiver was once The Moving People dropped it on
my mother's toe and broke it. (Broke the toe, not the receiver. It worked fine for many years after that. And Mom's
toe is fine too.) And so did my little nephew who had one of my amps with scary exposed tubes from the time he
was a wee lad. He not only survived and is in college now, but when he was three years old he knew how to fire up
the whole hifi even before his mom did. So don't underestimate how smart your kids or pets are unless they are
already prone to burning themselves on light bulbs. Or just put this amp up on a tall shelf out of the way. Actually

I'd be more worried about little kids breaking my $3000 moving coil cartridge needle. Or The Cleaning People...

Before plugging in your interconnects, take a quick visual inspection of the tubes. Sometimes either through
shipping or unpacking things get jostled. Make sure all tubes are firmly in their sockets. You might also verify that
none have turned white inside. That indicates that air has leaked inside the tube (or the vacuum leaked out!).
Though it is rare, a tube is sometimes cracked or broken in shipping. It would need to be replaced before powering

up the unit. Give us a holler if this happens to you.

SWITCHING ON

The power switch is located on the back panel. You shouldn't need to turn the Stingray around or get yourself
behind it. You should be able to "feel" the rocker switch located next to the AC power cord. Flip the switch away

from the power cord to turn on the Stingray or towards the power cord to turn off the unit. Easy 'nuff.

RUNNING

It is not recommended that you leave your Stingray always switched on. This only wastes electricity and tube life.
Do you leave your lights on when you are not home? The Stingray reaches peak operating condition in

approximately 30 minutes. Break-in from new is about a week although some people report it takes much longer.

TUBE LIFE

As with all tubes, their quality degrades with age. This is due to decreasing cathode emission, a natural process
found in all tubes. We recommend that you have your amplifier checked every 4-5 years, depending on usage. An

excessive increase in noise level or very unstable output tube bias can indicate the need to replace a tube.

5

CONNECTING YOUR STINGRAY

Setting up this integrated amplifier is rather easy. Please refer to page 8 for a diagram of the
back of the Stingray.

1. You will be connecting power last and turning the system on after all other connec­tions are made to prevent ugly noises as wires are connected and to prevent possible
damage to the amps and speakers. In general, it is best to make any connections
with the power off or the volume control turned all the way down. With all tube
amps, you MUST have speakers (or a load box) properly connected to the speaker
terminals before power is turned on. Without a speaker, the voltage swings can be
large enough to possibly cause an electrical arc inside a tube, tube socket or trans­former and this may damage the amp. Solid state amps can usually be fine with a
no-load condition but most of the time don't tolerate a short circuit. Most tube amps
will tolerate a short for a little bit, but we try to avoid this. OK?

2. Before plugging in your interconnects, take a quick visual inspection of the tubes.
Sometimes either through shipping or unpacking things get jostled. Make sure all
tubes are firmly in their sockets and standing straight up. You might also verify that
none have turned white inside. That indicates that air has leaked inside the tube (or
the vacuum leaked out!). Though it is rare, a tube is sometimes cracked or broken in
shipping. It would need to be replaced before powering the amp.

3. On rectangular chassis it is easy to specify front, back, sides etc - but on the 6 sided
Stingray we should adopt a convention and call the sides that have the RCA inputs
and input switching as Left-Back and Right-Back. We provide 4 left inputs on the
Left-Back and 4 right inputs on the Right-Back. We realize splitting left and right
this way with individual input select switches may be a problem for some - sorry.
We did it this way because a good percentage of people rely on only one source
95% of the time and because it provides you with the maximum stereo separation
and best signal flow.

4. Plug in your interconnects, one at a time, from each source, ie; CD, Tuner, AUX,
then connect each input to the appropriate RCA jack on the Stingray. All RCA jacks
are clearly labeled as to a typical function. Each input is functionally and
electronically the same - only the labels are different. You may have to separate or
split interconnects an extra 12 inches if they are the "paired" type or slide the loop
that holds the pair together back so they will make the spread. If you need to
connect a turntable (vinyl!) you will need a separate phono preamp to raise the level
from the tiny signal from the cartridge, and apply the RIAA EQ curveso it will
become a regular line level signal. The Manley Steelhead is a lovely choice for this
application, for example.

6

5. Connect the speaker leads to the terminals on the top far left and far right of the Stingray.
Be sure that the RED (+) positive terminal is connected to your positive (+) wire and the
NEGATIVE (-) (white or black) terminal is connected to your (-) Negative wire. Connect
the opposite ends to the speakers also RED (+) to RED (+) and Negative(-) to Negative(­). This insures that your speakers will be "in-phase". All too often people accidently
connect their speakers out-of-phase and it do sound strange. We have even seen this
happen in hi-fi trade shows and record company executive offices. There is always some
indication on the wire to help get "polarity" right but it may be as subtle as a "ridge" on
the insulation or different colored conductors. Most high quality speaker interconnects
are clearly labeled and/or color coded. Be sure that these connections are firm and solid.
We do not recommend using pliers or a wrench to tighten the terminals because one can
easily overtighten or mar the finish of the binding posts. Good finger tightening is usually
the best. No need to be an ape.

6. Before proceeding to the next step (power!) check that the On/Off switch is Off and the
volume is turned all the way down (anti-clockwise). Now connect the IEC power cable to
the back of the Stingray and then the other end to your mains wall socket.

7. Turn on the On/Off switch and let the Stingray "warm-up" for a few minutes. You should
be seeing the tubes begin to glow a bit. None should turn bright red - that would indicate
a problem. Let us start off checking with a favorite CD. Be sure that both input select
switches (Back-Left & Back-Right) are set to CD. Put the CD in PLAY and slowly turn
up the Volume - You should be getting sound from both speakers. If not, turn the power
off and check your connections from CD to Stingray and Stingray to Speakers.
Sometimes we don't get an interconnect pushed in enough for good contact. Power up
and try again. If you have sound, sit back and enjoy. Try your other inputs by turning the
input selectors to each source.

Sometimes if the switches haven't been used for awhile, the silver can tarnish a bit on the

internal switch contacts. Just switching them back and forth a few times rapidly will clear
this up. Excercise those switches once in a while.

7