SPHINX PROJECT EIGHTEEN User manual

1.
USER MANUAL
PROJECT EIGHTEEN
DUAL MONO STEREO POWER AMPLIFIER

SPHINX Project Eighteen
2
1. UNPACKING.......................................................................................................................................3
2. SPHINX WARRANTY CARD ..............................................................................................................3
3. THE POWER AMP AT A GLANCE.....................................................................................................4
Front panel...................................................................................................................................................4
Rear panel ...................................................................................................................................................5
4. INSTALLATION AND CONNECTIONS..............................................................................................6
Installation....................................................................................................................................................6
Connections in general................................................................................................................................6
Connecting loudspeakers............................................................................................................................6
Connecting the inputs..................................................................................................................................6
Balanced .............................................................................................................................................................6
Unbalanced.........................................................................................................................................................6
Connecting the optical cables......................................................................................................................7
Connecting the mains power cable..............................................................................................................7
5. OPERATION........................................................................................................................................8
Power On.....................................................................................................................................................8
Power off......................................................................................................................................................8
Warnings .....................................................................................................................................................8
If you encounter problems... ........................................................................................................................8
6. CARE AND MAINTENANCE...............................................................................................................9
7. TECHNISCHE DATEN........................................................................................................................9

SPHINX Project Eighteen
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Congratulations with your purchase of the
Sphinx Project Eighteen!
You are now part of an ever increasing group of
quality conscious audiophiles using Sphinx
products.
We are very proud of the tradition connected to the
SPHINX name especially concerning audio quality
perfection.
This manual will help you to gain a maximum
amount of pleasure and quality from your new
Sphinx Project Eighteen.
The power amp handles the largest signal peaks
and transients with ease, and has no problem with
any size and sort of loudspeaker load: even the
most demanding.
These characteristics are the result of several new
technologies and components. Like for instance the
unique power supply which assures a stable and
noise free operation. The special toroid transformer
(one for each channel!) of 650 VA has the size of a
1000 VA model: safely overspecified. Thanks to the
generous energy reserve of 66,000 µF (formed by
30 capacitors in parallel) unlimited power is
available for the largest signal peaks. Furthermore
there are three completely separate power supplies
for the input section, driver section and the logic
and indicator section.
Much attention has also been paid to the physical
layout, the positioning of components and the
internal grounding. This results in a equivalent input
noise value of <1 µV (<-120 dBV!): remarkable for a
pre-amp, but really astounding for a big power amp
with two transformers.
To obtain the maximum quality from this power amp
it is necessary to use it with top quality audio
components. So preferably use it with other Sphinx
components.
Your local dealer will be able to answer any
questions concerning other Sphinx audio
components.
1. UNPACKING
Before leaving the factory every Project Eighteen is
subjected to stringent and extensive technical and
exterior quality inspections.
This ensures you will enjoy many years of high
quality audio from a perfect looking product.
Attention: The power amp weighs over 24 kg!
Never lift it out of the carton without someone
helping you.
After unpacking your Project Eighteen we therefore
recommend you carefully check it for any transport
damage.
In case of damage: please contact your Sphinx
dealer immediately and retain all packing materials
for possible proof of damage and possible claims.
Even if the component is in perfect condition you
still should keep the packing materials. If you need
to transport your Project Eighteen at a later time it
will be best protected by the original packing
materials.
2. SPHINX WARRANTY CARD
Please takes this opportunity to fill out the enclosed
warranty card now!
Follow the instructions on the card or consult your
dealer.
Please send the card as soon as possible to the
return address (within 14 days after purchase).
Please read this manual carefully before you
install or use the Project Eighteen. It is
important to familiarise yourself with the
special functions, operation and possibilities
of the Sphinx Project Eighteen.

SPHINX Project Eighteen
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3. THE POWER AMP AT A GLANCE
Front panel
1. STANDBY: To switch the component on and off. 2. LED: Indicates the selected function:
stand-by red
on green.
12

SPHINX Project Eighteen
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Rear panel
3. RIGHT OUTPUT:To connect the cable from the
right loudspeaker:
red +
white -
4. CONTROL IN: To connect the optical cable
coming from another Sphinx component like a
pre-amp.
5. BALANCED RIGHT: To connect the XLR cable
(balanced cable) from the right output of the
signal source.
6. CINCH RIGHT: To connect the cinch cable from
the right output of the signal source.
7. CINCH/BALANCED INPUT: With this switch
you may select between the inputs:
up unbalanced (6 and 8)
down balanced (5 and 9)
8. CINCH LEFT: To connect the cinch cable from
the left output of the signal source.
9. BALANCED LEFT: To connect the XLR cable
(balanced cable) from the left output of the
signal source.
10. CONTROL OUT:To connect the optical cable
going to another Sphinx component.
11. LEFT OUTPUT:To connect the cable from the
left loudspeaker:
red +
white -
12. ON/OFF: This is the mains power master
switch.
13. AC POWER: Connect the power amp with the
cord to a mains outlet (230 - 240 VAC).
The mains fuse is placed behind the cover.
14. Manufacturer's label: Here you'll find important
data of this component such as serial number
and mains voltage to be used.
345
6
7 8 9 10 11 12 13
14

SPHINX Project Eighteen
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4. INSTALLATION AND CONNECTIONS
Installation
Attention: The power amp weighs more than 24
kg!
So make sure you place the Project Eighteen on a
stable and sturdy support.
Never 'stack' two power amps on top of each other.
The Project Eighteen will become warm so correct
placement is critical. Do not position it on top of or
close to other heat radiating equipment (such as
other power amps) or in direct sunlight.
Please ensure the unrestricted ventilation
around the component.
If you need to use the amp in a closed cabinet or on
a bookshelf you absolutely provide unrestricted
ventilation around the component.
To prevent any possible interference keep power
supply cables away from all audio cables.
If all these conditions will be met the Project
Eighteen shall perform to the extremely high
standards it is designed for.
Connections in general
Before you start connecting equipment it always is
wise to check whether all mains power cables of all
components are disconnected from the mains
outlets!
This will prevent any damage to the loudspeakers
and amplifiers caused by incorrect wiring or
settings.
Always use loudspeaker and audio cables and
connectors of the highest quality.
Siltech cable is used throughout internally so we
recommend using this same cable for all external
connections.
If you have the choice between longer loudspeaker
cables or longer audio cables, choose the latter
(cables between preamp and power amp will cause
the least signal quality loss).
Connecting loudspeakers
We recommend using a double pair of cables if this
is possible with the loudspeakers used (one pair for
the highs and another for the lows).
In most cases you will hear a substantial
improvement in the sound quality (but: be careful to
prevent shorted connections).
Your dealer can recommend the best cables and
connection methods.
Connect the red RIGHT OUTPUT terminal (3.) to
the red or '+' terminal of the right loudspeaker.
Connect the black RIGHT OUTPUT terminal (3.) to
the black or '—' terminal of the right loudspeaker.
Connect the left loudspeaker in the same way to the
LEFT OUTPUT terminals (11.)
When using unterminated cables please check
carefully if there are no 'loose ends' cause a short
between the '+' and the '—' of the terminals on amp
and loudspeakers!
Connecting the inputs
Make sure you connect L and R properly. Most
cinch cables use Red for the Right channel and
White or Black for Left.
All cinch connectors on the Project Eighteen's rear
panel have a red centre for the right channel and a
white one for the left channel.
The XLR connectors are marked BALANCED
RIGHT and LEFT.
When making the connections please refer to the
descriptions for parts 3. up to 13. on page 5.
The Project Eighteen has two input types
Balanced
To the BALANCED LEFT and RIGHT(600 Ω) inputs
you connect the corresponding outputs from the
pre-amp.
Unbalanced
The unbalanced inputs CINCH LEFT and CINCH
RIGHT (20 kΩ) can be used for any unbalanced line
level signal (like from a pre-amp).
Use only one type of input. The switch (7.) on the
rear panel lets you select between the type of
inputs.
Note: Do not place a so-called 'shorting connector'
in the unused input.

SPHINX Project Eighteen
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Connecting the optical cables
The Project Eighteen has an optical jack connector
for CONTROL IN and CONTROL OUT.
When the CONTROL IN of the Project Eighteen has
been connected to the CONTROL OUT of another
Sphinx component you don't have to switch the
Project Eighteen with ON/OFF switch (12.). The
power amp will automatically select Stand-by mode
as soon as the other component is set to stand-by.
In 'stand-by' mode the bias current of the power
amp is set to a lower level which drastically
decreases the temperature and power
consumption. On top of that it significantly
increases the life span of the component.
The power amp also warms up more speedily so
you will be able to enjoy it's maximum performance
without significant delay.
When the CONTROL OUT of the Project Eighteen
has been connected to the CONTROL IN of another
Sphinx component (which most likely will be another
power amp) this component will be selected to
stand-by by the Project Eighteen's stand-by mode.
Ensure proper connection of the optical cables
(from CONTROL OUT to CONTROL IN), otherwise
the LED next to the STANDBY button (1) on the
front panel may remain green although the stand-by
mode is activated.
If the Project Eighteen is placed in strong direct
sunlight the stand-by mode might be self-activated.
In that case you should place the supplied dummy
connector in the CONTROL IN (4.) jack (but only if
this is not being used).
We strongly recommend against placing the
component in direct sunlight though.
Connecting the mains power cable
Before you connect the cable please check
whether the mains voltage indicated on the
manufacturers label on the rear panel is the
same as your local mains voltage.
If not: please contact your dealer and do not
connect the component to the mains.
Connect the mains cable after you have connected
all other components in the system and have
double-checked all connections.

SPHINX Project Eighteen
8
5. OPERATION
Connect the mains cable of the Project Eighteen to
an mains outlet.
Only after you have connected all other
components, you may switch the Project Eighteen
on with the ON/OFF switch (12.) on the rear panel.
From now on you should switch the power amp on
and off with the STANDBY button (1.) on the front
panel or the STANDBY button of another Sphinx
component connected to the optical CONTROL IN
jack.
This way all circuits will remain at working
temperature and the audio quality will be 100 %
within 15 minutes after activating. On top of that it
considerably increases the life span of the
component.
The Project Eighteen is in stand-by mode and the
LED (2.) shows a red indication.
Power On
You switch the Project Eighteen on with the
STANDBY button: the LED becomes green.
If you activate the power amp for the first time or
after a long period of non-use with the power 'off'
the amp will be at maximum performance after one
hour.
From stand-by mode it only takes around 15
minutes.
Power off
You switch the Project Eighteen off (stand-by) with
the STANDBY button (1).
Only if you will not be using the amp for a long
period (e.g. during holidays) we recommend
switching the amp off with the ON/OFF switch (12.).
Because in stand-by mode the Project Eighteen's
power consumption is still around the 70 W mark.
Warnings
1. Never put two amps on top of each other.
2. The component should not be subjected to
moisture of fluids.
3. Do not touch the component and the
loudspeaker outputs in particular with moist
hands: this powerful amp can output voltages in
excess of 36 volt.
4. Before removing the top panel, you should
disconnect the mains cable and wait at least 30
minutes (because the power supply remains at
the maximum voltage for a long time). Removing
the top panel does void your warranty though:
the panel should therefore only be removed by
an official Sphinx service engineer!
5. Before disconnecting a loudspeaker or audio
cable, please switch of the component with the
ON/OFF switch (12.)
6. An AC extension cord should never be used
wholly or partly coiled: this poses a severe fire
risk!
If you encounter problems...
If after power on the protection circuits detect
something wrong the Project Eighteen will
immediately switch to stand-by: the LED indication
will be red.
In almost all occurrences the problem has to do with
the loudspeaker cables.
Check every single one and solve the problem.
If you can't find the problem or the cause is
definitely not the cables, please contact your Sphinx
dealer.
Should for some reason the mains fuse be
destroyed you should replace it with a new one of
exactly the same type and rating:
5x20 mm
250 VAC / 6 A / slow
The fuse sits behind the cover in the mains
connector (13.).
Never use a fuse of a different rating: this could
lead to serious damage and may cause fire!

SPHINX Project Eighteen
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6. CARE AND MAINTENANCE
Clean the exterior with a soft, lint-free, anti-static
cloth. Do not use force while wiping the surface.
To remove difficult stains use a few drops of
detergent on a moist cloth, sweep carefully and
wipe dry afterwards.
If some scratching might occur, please first consult
your Sphinx dealer. He can give you advice about
possible solutions.
Do not use polishing or cleaning agents: they
may damage the sensitive acrylic finish.
Do not use aerosol cleaning agents.
Most contain solvents which might actively react
and damage the acrylic finish.
7. TECHNICAL SPECIFICATIONS
Bandwidth 0 - 100,000 Hz (+0/-1 dB, with input filter)
Phase response error <1° (0 - 20,000 Hz)
Gain 30 dB max.
Minimum Power Output (1 - 20,000 Hz) >2x 160 W into 8 ohm (22.0 dBW), THD<0.01%
>2x 280 W into 4 ohm (24.5 dBW), THD<0.01%
>2x 420 W into 2 ohm (26.2 dBW), THD<0.01%
Output voltage / current, max. 36 V / 43 A
THD+N (IHF-A) <0.01% (1 W into 8 ohm, 1 - 20,000 Hz)
IMD <0.01% (100 W into 8 ohm)
S/N ratio (IHF-A) >120 dB (1 W into 8 ohm)
Common Mode Rejection Ratio >80 dB (@ 100 Hz)
Slew rate >50 V/µs
Damping factor >2000 (1 - 20,000 Hz)
Input cinch: unbalanced / XLR: balanced
level, nominal 1.25V ( 1.9 dBV) / 1.25 V ( 1.9 dBV)
impedance 20 kohm / 600 ohm
Supply capacitance 132,000 µF total
Power consumption 1500 W max. (70 W standby)
Dimensions (h x w x d) 143 x 482 x 452 mm
Weight 24 kg
This unit conforms to the EMC interference regulations from the EU and to the CE standards.
This unit complies with safety regulation VDE 0860 and thus with international safety regulation IEC 65.
Technical specifications can be changed by SPHINX without prior notice if technical developments make this
necessary.
©1999 Audioscript BV