1.
SERVICE MANUAL
PROJECT TWELVE
MONO
POWER AMPLIFIER
SPHINX Project Twelve Service Manual
Contents
1. UNPACKING .......................................................................................................................................3
2. SPHINX WARRANTY CARD ..............................................................................................................3
3. CONTACTING THE MANUFACTURER .............................................................................................3
4. THE POWER AMP AT A GLANCE.....................................................................................................4
Front panel................................................................................................................................................... 4
Rear panel ................................................................................................................................................... 5
5. TECHNICAL SPECIFICATIONS .........................................................................................................6
6. GENERAL CHECKLIST......................................................................................................................7
Optical connections ..................................................................................................................................... 7
Switching the amp on................................................................................................................................... 7
Protection mode........................................................................................................................................... 7
Cables.......................................................................................................................................................... 7
7. USING THE AMP WITHOUT PROTECTION CIRCUIT......................................................................8
Removing the protection circuit board ......................................................................................................... 8
Repositioning the protection circuit board.................................................................................................... 8
8. ADJUSTMENT PROCEDURES..........................................................................................................9
Bias.............................................................................................................................................................. 9
Offset ......................................................................................................................................................... 10
Common mode .......................................................................................................................................... 10
9. PROBLEMS AND SOLUTIONS........................................................................................................11
10. DIAGRAMS AND PARTS LISTS ....................................................................................................12
Connection diagram for testing the project 12 ........................................................................................... 13
Schematic layout of project 12 with securityprint....................................................................................... 14
Schematic layout of all relevant parts ........................................................................................................ 15
Project 12 amplifier diagram ...................................................................................................................... 16
Project 12 protection diagram.................................................................................................................... 17
PCB drawings of Project 12 ....................................................................................................................... 18
Partlist amplifier ......................................................................................................................................... 19
Partlist protection ....................................................................................................................................... 22
2
SPHINX Project Twelve Service Manual
The Sphinx Project Twelve design
1. UNPACKING
The Sphinx Project Twelve was designed for the
Before leaving the factory every Project Twelve is
ever-increasing group of quality-conscious
subjected to stringent and extensive technical and
audiophiles.
exterior quality inspections. This ensures the user
We are very proud of the tradition connected with
many years of high quality audio from a perfect-
the SPHINX name, especially concerning audio
looking product.
quality perfection.
We recommend owners to ship the Project Twelve
This service manual will help you to optimally
in its original carton.
service and repair the Sphinx Project Twelve Mono
Power Amplifier.
After unpacking the Project Twelve we therefore
recommend you carefully check it for any transport
damage.
The design is based on the long experience of the
If you find any damage and the product has not
Sphinx design team with ultra-wide bandwidth
been shipped in the original carton the ensuing
power FETs.
repair costs will not be covered by the warranty.
These have an unique and extremely wide power
bandwidth exceeding 1.5 MHz, a very high slew
rate of over 100 V/µs and an unequalled perfect
phase linearity over the complete frequency
2. SPHINX WARRANTY CARD
bandwidth.
To be entitled to any warranty repairs the owner
Six of these 100 W FETs are used to obtain
must have send the filled out warranty card to
maximum reliability.
Sphinx or a distributor where it has been registered.
The extremely low output impedance results in a
Other regulations may apply in your specific
damping factor of over 600!
country: when in doubt, please consult the proper
Together with the very 'heavy' power supply and its
authorities.
large energy buffer of 26,920 µF, this results in an
effortless sound with a very large dynamic range
and an unsurpassed transient response.
3. CONTACTING THE MANUFACTURER
Much attention has also been paid to the physical
layout, the positioning of components and the
In case of any problem not covered in this manual
internal grounding. This results in an equivalent
or if you have other questions you may contact the
input noise value of <1 µV (<-120 dBV): remarkable
Sphinx International Service Department in The
for a pre-amp, but really astounding for a big power
Netherlands (local time: GMT +1h) during office
amp with two transformers.
hours at the following numbers:
All of this means that the Project Twelve can work
Telephone [phone]
with all kind of loads from every loudspeaker: even
Fax [phone]
the most difficult ones like electrostatic and
E-mail [e-mail]
magnetostatic...
It is always very helpful and efficient if you have all
To obtain the maximum quality from this power amp
relevant information about the specific product and
it is necessary to use it with top quality audio
the problem ready.
components preferably with other Sphinx
components.
Please also refer to the User Manual of the
Project Twelve for information about
functions not described in this manual.
It is important to familiarise yourself with the
special functions, operation and possibilities
of the Sphinx Project Twelve.
3
SPHINX Project Twelve Service Manual
4. THE POWER AMP AT A GLANCE
Front panel
1. LED: Indicates the selected function:
stand-by red
on green
protection blinking red.
2. STANDBY: To switch the component on and off.
4
SPHINX Project Twelve Service Manual
Rear panel
3. BALANCED/UNBALANCED: With this switch 6. MAINS: This is the combined mains master
you may select the balanced input (5.) or the switch (0/1) and input.
unbalanced input (8).
MAINS: To connect the power amp to a mains
4. CONTROL IN: To connect the optical cable
outlet (230 - 240 VAC).
from another Sphinx component like a pre-amp.
CONTROL OUT: To connect the optical cable 7. OUTPUT: To connect the cable from the
that goes to another Sphinx component. loudspeaker:
red +
5. BALANCED INPUT: To connect the balanced
white -
XLR cable from the pre-amp output.
8. UNBALANCED INPUT: To connect the
unbalanced cinch cable from the pre-amp
output.
Manufacturer's label: Here you'll find
important data on this component, such as
serial number and mains voltage to be used.
5
SPHINX Project Twelve Service Manual
5. TECHNICAL SPECIFICATIONS
Bandwidth 0 - 1.5 MHz (+0/-3 dB)
0 - 203,000 Hz after RF input filter
Phase response error <1° (0 - 20,000 Hz)
Gain (balanced) 29.5 dB max. (x 29.9)
( unbalanced) 29.5 dB max. (x 29.9)
Minimum Power Output (1 - 20,000 Hz, 1 W = 0 >151 W into 8 ohm (21.8 dBW), THD <0.01%
dBW) >246 W into 4 ohm (23.9 dBW), THD <0.01%
>340 W into 2 ohm (25.3 dBW), THD <0.01%
Output voltage / current, max. 36 V / 16 A
THD+N (IHF-A) <0.006% (100 W into 8 ohm, 1 - 20,000 Hz)
IMD <0.010% ( 70 W into 8 ohm)
S/N ratio (IHF-A) >120 dB
Slew rate >20 V/µs
Common Mode Rejection Ratio >30dB @ 100 Hz
Damping factor >645 @ 10 Hz
>629 @ 100 Hz
>595 @ 1 kHz
>155 @ 10 kHz
Input XLR balanced / cinch WBT unbalanced
level, nominal 1.25 V (1.9 dBV) / 1.25 V (1.9 dBV)
impedance 600 ohm / 20 kohm
Supply capacitance 26,920 µF total
Power consumption 600 W max. (5 W standby)
Power transformer, primary 230 VAC / 115 VAC
secondary 45 VAC / 3,33 A (2x)
Temperature protection 70 °C / 158 F
Maximum DC-offset +350 mV and  350 mV
Short circuit protection Measured at source resistor R31
Dimensions (h x w x d) 68 x 250 x 340 mm
Weight 6,5 kg
This unit conforms to the EMC interference regulations issued by the EU and to the CE standards.
This unit complies with safety regulation VDE 0860 and therefore with international safety regulation IEC 65.
Technical specifications may be changed by SPHINX without prior notice if technical developments make this
necessary.
6
SPHINX Project Twelve Service Manual
6. GENERAL CHECKLIST
Before you test or service the Project Twelve
Protection mode
please check the following items. They will give
If - after switching on - the red LED (1.) blinks
information about the current status of the amplifier.
rapidly (2x per second) this indicates that the
protection mode is active.
Note: The Project Twelve will become warm, so
This may be caused by one of the following
correct placement is critical. Do not position it on
problems:
top of or close to other heat-radiating equipment
(such as other power amps) or in direct sunlight.
1. The operational temperature exceeds 70 °C.
Please ensure unrestricted ventilation around
2. The output DC-offset exceeds +/- 350 mV.
the component.
3. The output is shorted (current-limiter active)
Warning!
Optical connections
The output Short-circuit protection will be
The optical CONTROL IN (4.) is light-sensitive. A
activated at output currents of over 27A. At
strong light source might therefore activate the
lower output currents (AC or DC) the amplifier
CONTROL function and switch the Project Twelve
has no direct protection. At continuous large
to Standby.
currents, the temperature protection will take
While this mode has priority the amplifier can not
over.
be activated with the Standby switch at the front
panel.
Before you start connecting equipment it is always
4. Power supply voltage is wrongly connected or
wise to check whether all the mains cables of all
low (for correct voltage see underside of PJ 12)
components are disconnected from the mains
outlets!
This will prevent any damage to the loudspeakers
The protection mode will do the following things:
and amplifiers caused by incorrect wiring or
settings.
1. Disconnect the amplifier output.
2. Disconnect the amplifier input.
Connect the mains cable after you have connected
all other components in the system and have
3. Reset the bias current to 0 mA.
double-checked all connections.
The protection mode can only be deactivated by
switching the amplifier off with the Mains Switch (6.)
If you use more than one Project Twelve connect
and leave it off for at least 30 seconds.
hem all to the same mains outlet and phase.
If the amplifier is switched on again within those 30
seconds the protection mode will automatically be
Switching the amp on
activated.
Before you switch the power amp on you should
Note: This also happens if the amplifier worked
always first:
properly before switching it off!
" connect a pre-amp
" connect the pre-amp s Control Out to the power
amp s Control In
Cables
" or place the dummy plug in the Control IN
Always use loudspeaker and audio cables and
connector of the power amp.
connectors of the highest quality.
After switching the amplifier ON the red LED (1.)
Siltech cable is used throughout internally and we
will first blink slowly (1x per second) and then will
recommend using this same cable for all external
light continuously.
connections.
The amp is now in Standby mode.
If you have the choice between longer loudspeaker
Pressing the Standby-button (2.) will activate the
cables or longer audio cables, choose the latter
amplifier and the LED turns to green.
(cables between pre-amp and power amp will
cause the least signal quality loss).
7
SPHINX Project Twelve Service Manual
Repositioning the protection circuit board
7. USING THE AMP WITHOUT To reposition the protection circuit board you use
the steps from the previous  Removing the&  -
PROTECTION CIRCUIT
procedure but in reverse order.
1. Reposition the jumper from JP1 & JP2 to JP2 &
To adjust the internal controls of the Project Twelve
JP3.
the protection circuit board may be removed.
If not, the protection circuit will not be able to
This ensures that all adjustment points on the main
disconnect the amplifier s output.
board are freely visible and accessible (instead of
through small openings in the protection circuit 2. Position the board over the mounting positions
board). and stick the Balanced/Unbalanced button
through the appropriate opening in the rear
panel of the housing.
WARNING!
3. Carefully insert the rear connector into the
The amplifier may be used without the protection
corresponding main circuit board socket and
circuit.
then the front connector in it s socket.
We do not recommend this however while this
prevents the output from being disconnected in
Attention:
case of any malfunction.
Incorrectly positioned connectors may cause
damage to the Project Twelve and the pre-amp.
SPHINX is not responsible for any damage
caused by the removal of the protection
circuit or the use of the amp without the
protection circuit!
4. Fix the protection circuit board position with the
two small screws.
5. Solder the five wires to their correct positions
Removing the protection circuit board
(position #1 is the one at the rear, see also the
drawing):
The protection circuit board is mounted on top of
1) Red (+) wire from BALANCED IN
the upper main printed circuit board of the amplifier.
2) Red (+) wire from UNBALANCED IN
The drawing  Schematic layout of project 12 with
securityprint (page 14) shows the main board of 3) Black wire (ground) from BALANCED IN
the Project Twelve with the protection circuit 4) Black wire (ground) from UNBALANCED IN
including all the parts mentioned below. Use the
5) Blue (-) wire from BALANCED IN.
following steps:
6. Solder the two PTC-resistors to the circuit
1. Remove the top cover plate of the amp. It is
board.
fixed with one hex screw (M4x12) at the rear
panel
7. Replace the top cover plate of the housing and
fix it with the hex screw.
2. Remove the two small screws (M3x6) of the
protection circuit board.
3. Unsolder the five wires at the top-left corner
(Audio-IN).
4. Unsolder the two PTC-resistors (for the over-
temperature protection at 70 °C).
5. Carefully remove the circuit board (there is only
(*) If there is no Servicing Cable available you may
one way of doing this due to the mounted
make one yourself using a suitable connector.
Balanced/Unbalanced switch):
Connect the wires as follows:
a) Lift up the front side of the board so the large
" Pin 1 (and 2) = negative signal: connect to blue
connector is disconnected from the main circuit
wire from Balanced In
board.
" Pin 3 (and 4) = ground: connect to black wire of
b) Lift the rear side of the board to disconnect
both inputs
the other connector.
" Pin 5 (and 6) = positive signal: connect to red
Now you may remove the board.
wire of both inputs
6. Connect the input signal to the main circuit
The 6 pin connector at the main board then can be
board with the special Servicing Cable (*).
used as the signal input.
7. Reposition the jumper from JP2 & JP3 to JP1 &
JP2.
The output relay now works without control
signal from the protection circuit.
8
SPHINX Project Twelve Service Manual
8. ADJUSTMENT PROCEDURES
Bias
The Project Twelve has three adjustable settings:
With this procedure you set the proper bias level for
the power FETs. This ensures their Class A
1. Bias: to set the bias current of the power-FETs
operation at low power levels.
2. Offset: to set the minimal DC voltage for the
output
Connect the amplifier according to the drawing
 conection diagram for testing the project 12 (page
3. Common Mode: to maximise the common
13).
mode rejection of the balanced input
The input of the amplifier must be shorted (by way
of the MUTE function of the oscillator).
Re-adjustment of one or more might be necessary
due to ageing or when parts have been replaced or
repaired. " Switch the amplifier ON and wait until it has
reached the proper working temperature (this
takes an hour).
Attention:
When re-adjusting any setting please ensure that " Set the millivolt-meter to the DC-range.
there is no loudspeaker connected to the output! " Place the two measuring clips of the meter
Otherwise the loudspeaker may be seriously across one of the source resistors (R30, R31,
damaged. R39, R40, R43 or R45: see schematic at page
15).
" The level should be 10 mV DC (Ä…2 mV).
If not: adjust potmeter P2 until the level is
10 mV (P2 can be reached via the  bias
Attention:
adjustment hole in the protection circuit board).
The amplifier is able to generate high output
voltages of over + or -60 V.
Please be very careful during the adjustments!
Attention:
All source resistors must show the same 10 mV
value. If not this indicates that the FETs are not
accurately matched and their variance is too high.
After removing the top cover plate you will see the
This will cause offset- and bias-problems which can
three main sections of the amplifier:
be detected with a THD analyser as a very specific
1. The power transformer
type of distortion.
2. The main printed circuit board holding the
In that case you should replace the FET sextuplet
actual audio amplifier
with a new one (3 matched ones and their inverse
3. The protection circuit board responsible for counterparts): they can be ordered from SPHINX.
switching the Project Twelve on and off.
" Switch the oscillator on and set it to 1 kHz and a
level of 0 dBu.
" Check the distortion with a THD analyser: it
should be conform the specified values (0.006%
IHF-A @ 1 kHz).
" If this is correct the procedure is finished.
" You may now switch off the amplifier or
continue with another adjustment procedure.
9
SPHINX Project Twelve Service Manual
Offset Common mode
The Offset adjustment procedure minimises the DC The Common mode adjustment procedure
offset value of the amplifier output. This DC offset is minimises the amplification error of the (internal)
important when capacitive loads are used, such as differential amplifier.
electrostatic loudspeakers. These loudspeakers If the balanced input amplifier receives an identical
often use a very low-impedance step-up signal at the normal (+) and inverted (-) input the
transformer. The amplifier  sees this load as a output signal will be zero. This helps to reduce the
short for the DC voltage. effect of external noise signals while these will be
induced at the same level in both signal
Connect the amplifier according to the drawing conductors.
 Connection diagram for testing the project 12 The Common Mode adjustment is optimally set
(page 13). during manufacturing (the error is as low as
The input of the amplifier must be shorted (by way possible).
of the MUTE function of the oscillator).
Connect the amplifier according to the drawing
 Connection diagram for testing the project 12
Attention:
(page 13, except with both + and  input connected
Be careful not to trip the offset protection mode. It
to eachother, and use the special input connector.
will activate when the output DC offset exceeds +/-
This connector supplies both the plus (+) and
350 mV.
minus (-) input pins of the XLR with the same
This mode can only be reset by switching off the
signal.
amplifier with the Mains switch (6.) and switching it
The  balanced/unbalanced -switch on the rear panel
on again after a waiting period of at least 30
must be set to  balanced .
seconds.
Please be careful during the adjustments!
If there is no signal analyser available you may use
an oscilloscope at the output to view the waveform.
" Switch the amplifier ON and wait until it has
reached the proper working temperature (this
" Switch the amplifier ON and wait until it has
takes an hour).
reached the proper working temperature (this
" Set the millivolt-meter to the DC-range.
takes an hour).
" Place the measurement clips of the meter over
" Switch the oscillator on and set it to 1 kHz and a
the output terminal.
level of 0 dBu.
" The level should not exceed +5 or -5 mV DC.
" Adjust potmeter P3 until the minimum level is
If not: adjust potmeter P1 until the level is within
set (P3 can be reached via the  bal. adjustment
this range (P1 can be reached via the  offset
hole in the protection circuit board).
adjustment hole in the protection circuit board).
When using a phase analyser the minimum
" Switch the oscillator on and set it to 1 kHz and a
point is reached when the output phase
level of 0 dBu.
reverses 180° re. the input.
" Check the distortion with a THD analyser: it
" Also check the setting at 10 Hz, 100 Hz and
should be conform the specified values (0.006%
10 kHz. Readjust when necessary.
IHF-A @ 1 kHz).
" If the common mode is at minimum level at all
" If this is correct the procedure is finished.
frequencies the adjustment is completed.
" You may now switch off the amplifier or
" You may now switch off the amplifier or
continue with another adjustment procedure.
continue with another adjustment procedure.
10
SPHINX Project Twelve Service Manual
9. PROBLEMS AND SOLUTIONS
Please also send (by fax or e-mail) the specific
At the moment of writing the Project Twelve has
information to the Sphinx International Service
one known specific problem.
Department (see page 3): this info can then be
If in the future you encounter any problem(s) you
added to the general database to aid others.
may enter the info in this table. This table can then
be used for future reference.
Problem Cause Solution Refer to
page&
Protection is not functioning Jumpercap is on JP1&JP2, Place jumpercap on JP2&JP3 15
properly, Amplifier is in  test -mode
Cannot adjust common mode Capacitor C2 is short-circuited, Replace capacitor C2 16
properly,
11
SPHINX Project Twelve Service Manual
10. DIAGRAMS AND PARTS LISTS
The next pages contain a complete set of schematic drawings including the associated parts lists (if applicable).
Connection diagram for testing the project 12 ........................................................................................... 13
Schematic layout of project 12 with securityprint....................................................................................... 14
Schematic layout of all relevant parts ........................................................................................................ 15
Project 12 amplifier diagram ...................................................................................................................... 16
Project 12 protection diagram.................................................................................................................... 17
PCB drawings of Project 12 ....................................................................................................................... 18
Partlist amplifier ......................................................................................................................................... 19
Partlist protection ....................................................................................................................................... 22
12
SPHINX Project Twelve Service Manual
Connection diagram for testing the project 12
Oscillator
Frequency
x
THD
Amplitude
y
time/div
gnd
out1 out2
gnd
inp1 inp1
inp2 THD out inp2
(+) (-) (+) (-)
N.C. N.C.
Project Twelve
A
A
Voffset
13
SPHINX Project Twelve Service Manual
Schematic layout of project 12 with securityprint
Small connector (audio in)
Pin 1
Positive BALANCED IN (red)
Pin assignment
pin 1
Pin 1 - input Pin 4 gnd
Positive UNBALANCED IN (red)
Pin 2 - input Pin 5 + input
Ground BALANCED IN (black) pin 6 Pin 3 gnd Pin 6 + input
Bal. screw
Ground UNBALANCED IN (black)
Negative BALANCED IN (blue) Pin 5
Security Print
screw
Large Connector
Large connector Pin Voltage
Pin 1 5 V Pin 7 0 V Pin 13 2 V Pin 19 0 V
Pin 2 -2 V Pin 8 0 V Pin 14 0.7 V Pin 20 2 V
Pin 3 -60 V Pin 9 0 V Pin 15 60 V Pin 21 0 V
Pin 4 0 V Pin 10 0 V Pin 16 0 V Pin 22 0 V
Pin 5 -15 V Pin 11 0 V Pin 17 0 V
Pin 6 0 V Pin 12 15 V Pin 18 0 V
Project Twelve main board
14
Small connector
Input wires
Offset
Attached to heatsink
PTC-connector
PTC-connector
Attached to heatsink
BIAS
Pin 1
Pin 22
SPHINX Project Twelve Service Manual
Schematic layout of all relevant parts
P3
R31 R43
Source resistor Source Resistor
P1
Offset
R40 R39
Source resistor Source resistor
Biasing
P2
R30
R45
Jp1
Source resistor Jp2 Source resistor
Jp3
15
Com. mode
SPHINX Project Twelve Service Manual
Project 12 amplifier diagram
GND
C129 C130 C131 C132 C133 C134 C135
60.5V R22
2R2
C11 C12 R7 R8 R16
C141 C141 C140 C139 C138 C137 C136
220uF/100V 100nF 820R 820R 56R
+ + + + + + +
C112
5mA 70mA 100mA 100mA 100mA 100mA C220nF/250V
R15 R17 R48
59V 59V 470R / 2W
GND Q6
Q539R 39R
R6 2SA970 GND
120K
2SA970 C5
100 pF
9.3V Q2 Q3 R49
Q10 R25 470R / 2W
2SC2705
2SC1775 2SC1775
22R
C3 R5 Q12 R28 R37 R41
1uF 22K R14 2SC4382 100R 100R 100R
18K C4
1.4mA 1.4mA
100nF
M14 M17 M19
GND
Q1 opto+ 2SK1529 2SK1529 2SK1529
D6
R1 D1 D2 R4
1N4007 16
Sig1+ D3
1K 18K ZY15V
Sig2+
2SK389
C2 R2 R18
220pF 18K 3K3 R30 R38 R43 R44
P1
0.22R 0.22R 0.22R 22K
200R opto-
P2
L1
R24 R27
5V 3.93V 1
R3 C6 1K 56R/2W EE-K-021
GND 604R 200R 100nF
Q9 A GND
R9 R10
2SC2240 R33
22R 22R R31 R40 R45
3.75mA R19 0.22R 0.22R 0.22R
10R/5W
220R
B D4
P3 ZY15V
R32 R34
100R
47R/2W 10R/5W
Sig1- M15 M18 M20
2SJ200 2SJ200 2SJ200
Sig2- R46 3.75mA D7
2.75mA
604R 1N4007
C7 C8
C1 R11 GND 47nF 330nF
1nF 1K R29 R38 R42
R26 2 R50
GND 68R 68R 68R
Agnd1 470R / 2W
22R
Agnd2 R13 Q13 GND
Q4 22K 2SA1668
GND
Q11
Q7 GND
Q8 2SA1145
2SC2240
2SC1775
R51
GND 2SC2240 5mA 70mA 100mA 100mA 100mA 100mA
C114 C113 C115 C116 C117 C118 C119 470R / 2W
+ + + + + + +
D1 C111
+
R12 C9 R20 R21 220nF/250V
C15 C14 475R 100nF 300R 300R
R23
220uF/100V 100nF
2R2
-60.5V
C126 C125 C124 C123 C122 C121 C120
GND
Opto+
Bias 1 +60V
2SC1775
17 1
R35 Q16
Opto1 a
A
RL1
220R
D17
R36 D2 REL1
C19
1N4007
100R 1N4148
1N 14
b
B
GND Opto-
16
2.95W
4.15W
Sub.
4.15W
2.95W
1.87V
C10
100uF/16V
+
+
+
+
+
+
+
+
+
+
+
+
+
+
SPHINX Project Twelve Service Manual
Project 12 protection diagram
+15V +5V R209
IC201
+5V +5V 18 LED red
7805
560R
1 3 C209
12 Vin Vout
1µ5/16V C211
R223 R201 19
100n
4k7
390R
R202 GND
C204
C201 + C203 C210 GND GND
NTC1+ R210
4k7 20 LED green
100n 100n
10µ/25V
560R
R224 C203 100n
6 390R 100n C212
R208
7 NTC1- 100n
4k7
8
GND C208
9 +5V GND
16 R211
10 GND X1 IC282
11
1n 15 560R
R203 X2
GND 6 D201
5 4k7 RB0 C213
17 7 OPTOUT
R204 RA0 RB1 100n
18 8
NTC2+ RA1 RB2
-15V 1 9
4k7 RA2 RB3
2 10 +5V
RA3 RB4 GND
C206 3 11
REL1B RA4 RB5
SIG-1 100n 12
RB6
SIG-2 NTC2- 4 13 R212
SIG- /MCRL RB7
100k
GND
PIC16C71
R2 R205 R206
Q201
AGND_1 2k2 +63V 15 +5V
C214
OPTIN
INP1 10k 47k R235
AGND 100n
INP3 1k
R207 GND
R3 C207
4k7
22k2 100n GND
R213
SIG+_1 R234 R217
V++MCLR RB6 RB7 Vss 17 STANDBY
4k7 4k7
SIG+ GND 560R
SIG+1
R214
SIG+2 21 C215
REL1C 2k2
100n
R218
STANDBY C220 C218
R1 10k
100n 100n Q203 14 RELAY
314R
22 BC807 GND
R215
Q202
GND R219
SHA-2XWIS +5V BC879
4k7 2k2
OVER CUR. D202
R216
S1.2 1 C216
2k2
100n
R229 1N4148
4k7
U200A C217
S1.1
3 100n
D204 GND GND
1
2 R225
R230 1N4148
GND 1k
390R GND
DC detection LM324 U200C Q204
R222 R221
10 BC807
16 +5V
8 R226
10k 10k
9 4k7
+ C219
D207 R220 U200E
REL1A
U200B
330µ/6V3 4
5V1 1M GND R231 D203
5 GND LM324
MT2 6V
390R D205 LM324 BYD77
7
11
6 U200D
D206 1N4148
GND 12 R227 R228
5V1 -15V
LM324
14 1k 1k
R232 -15V
13
10k
GND
GND LM324
R233
4k7
-15V
17
+
GND
2
14
5
VCC
GND
SPHINX Project Twelve Service Manual
PCB drawings of Project 12
Because there is a significant image-quality loss during the conversion of the drawings, the PCB-drawings are
located in seperate files.
These files are in PDF-format (Adobé Acrobat 3.0 Reader).
" Pj12Main.PDF for Mainboard
" Pj12Protect.PDF for Protectionboard
18
SPHINX Project Twelve Service Manual
Partlist amplifier
Designator Part Type Description
C1 1nF Capacitor
C10 100uF/16V Capacitor
C11 220uF/100V Capacitor
C111 220nF/250V Capacitor
C112 C220nF/250V Capacitor
C113 1000uF/100V Capacitor
C114 1000uF/100V Capacitor
C115 1000uF/100V Capacitor
C116 1000uF/100V Capacitor
C117 1000uF/100V Capacitor
C118 1000uF/100V Capacitor
C119 1000uF/100V Capacitor
C12 100nF Capacitor
C120 1000uF/100V Capacitor
C121 1000uF/100V Capacitor
C122 1000uF/100V Capacitor
C123 1000uF/100V Capacitor
C124 1000uF/100V Capacitor
C125 1000uF/100V Capacitor
C126 1000uF/100V Capacitor
C129 1000uF/100V Capacitor
C130 1000uF/100V Capacitor
C131 1000uF/100V Capacitor
C132 1000uF/100V Capacitor
C133 1000uF/100V Capacitor
C134 1000uF/100V Capacitor
C135 1000uF/100V Capacitor
C136 1000uF/100V Capacitor
C137 1000uF/100V Capacitor
C138 1000uF/100V Capacitor
C139 1000uF/100V Capacitor
C14 100nF Capacitor
C140 1000uF/100V Capacitor
C141 1000uF/100V Capacitor
C141 1000uF/100V Capacitor
C15 220uF/100V Capacitor
C19 1N Capacitor
C2 220pF Capacitor
C3 1uF Capacitor
C4 100nF Capacitor
C5 100 pF Capacitor Styroflex
C6 100nF Capacitor
C7 47nF Capacitor
C8 330nF Capacitor
C9 100nF Capacitor
D1 LED LED
D17 1N4007 Diode
D2 1N4148 Diode
D3 ZY15V Zener diode
D4 ZY15V Zener diode
D6 1N4007 Diode
D7 1N4007 Diode
19
SPHINX Project Twelve Service Manual
Designator Part Type Description
L1 EE-K-021 Coil
M14 2SK1529 Transistor
M15 2SJ200 Transistor
M17 2SK1529 Transistor
M18 2SJ200 Transistor
M19 2SK1529 Transistor
M20 2SJ200 Transistor
Opto1 OPTO COUPLER Opto Coupler
P1 200R Variable resistor
P2 200R Variable resistor
P3 100R Variable resistor
Q1 2SK389 Transistor
Q10 2SC2705 Transistor
Q11 2SA1145 Transistor
Q12 2SC4382 Transistor
Q13 2SA1668 Transistor
Q16 2SC1775 Transistor
Q2 2SC1775 Transistor
Q3 2SC1775 Transistor
Q4 2SC1775 Transistor
Q5 2SA970 Transistor
Q6 2SA970 Transistor
Q7 2SC2240 Transistor
Q8 2SC2240 Transistor
Q9 2SC2240 Transistor
R1 1K Resistor
R10 22R Resistor
R11 1K Resistor
R12 475R Resistor
R13 22K Resistor
R14 18K Resistor
R15 39R Resistor
R16 56R Resistor
R17 39R Resistor
R18 3K3 Resistor
R19 220R Resistor
R2 18K Resistor
R20 300R Resistor
R21 300R Resistor
R22 2R2 Resistor
R23 2R2 Resistor
R24 1K Resistor
R25 22R Resistor
R26 22R Resistor
R27 56R/2W Resistor 2W
R28 100R Resistor
R29 68R Resistor
R3 604R Resistor
R30 0.22R Resistor 5W
R31 0.22R Resistor 5W
R32 47R/2W Resistor 2W
20
SPHINX Project Twelve Service Manual
Designator Part Type Description
R33 10R/5W Resistor 5W
R34 10R/5W Resistor 5W
R35 220R Resistor
R36 100R Resistor
R37 100R Resistor
R38 0.22R Resistor 5W
R38 68R Resistor
R4 18K Resistor
R40 0.22R Resistor 5W
R41 100R Resistor
R42 68R Resistor
R43 0.22R Resistor 5W
R44 22K Resistor
R45 0.22R Resistor 5W
R46 604R Resistor
R48 470R / 2W Resistor 2W
R49 470R / 2W Resistor 2W
R5 22K Resistor
R50 470R / 2W Resistor 2W
R51 470R / 2W Resistor 2W
R6 120K Resistor
R7 820R Resistor
R8 820R Resistor
R9 22R Resistor
RL1 REL1 Relay
21
SPHINX Project Twelve Service Manual
Partlist protection
Designator Part Type Description
C201 10µ/25V Electrolitic capacitor
C203 100n MKT capacitor
C203 100n MKT capacitor
C204 100n MKT capacitor
C206 100n MKT capacitor
C207 100n MKT capacitor
C208 1n MKT capacitor
C209 1µ5/16V Electrolitic capacitor
C210 100n MKT capacitor
C211 100n MKT capacitor
C212 100n MKT capacitor
C213 100n MKT capacitor
C214 100n MKT capacitor
C215 100n MKT capacitor
C216 100n MKT capacitor
C217 100n MKT capacitor
C218 100n MKT capacitor
C219 330µ/6V3 Electrolitic capacitor
C220 100n MKT capacitor
D201 OPTOUT optical output
D202 1N4148 DIODE
D203 BYD77 DIODE
D204 1N4148 DIODE
D205 1N4148 DIODE
D206 5V1 ZENER DIODE
D207 5V1 ZENER DIODE
IC201 LM7805 Voltage regulator
IC282 PIC16C71 Microcontroller
Q201 OPTIN optical output
Q202 BC879 Transistor
Q203 BC807 Transistor
Q204 BC807 Transistor
R1 314R Resistor
R2 2k2 Resistor
R201 4k7 Resistor
R202 4k7 Resistor
R203 4k7 Resistor
R204 4k7 Resistor
R205 10k Resistor
R206 47k Resistor
R207 4k7 Resistor
R208 4k7 Resistor
R209 560R Resistor
R210 560R Resistor
22
SPHINX Project Twelve Service Manual
Designator Part Type Description
R211 560R Resistor
R212 100k Resistor
R213 560R Resistor
R214 2k2 Resistor
R215 2k2 Resistor
R216 2k2 Resistor
R217 4k7 Resistor
R218 10k Resistor
R219 4k7 Resistor
R220 1M Resistor
R221 10k Resistor
R222 10k Resistor
R223 390R Resistor
R224 390R Resistor
R225 1k Resistor
R226 4k7 Resistor
R227 1k Resistor
R228 1k Resistor
R229 4k7 Resistor
R230 390R Resistor
R231 390R Resistor
R232 10k Resistor
R233 4k7 Resistor
R234 4k7 Resistor
R235 1k Resistor
R3 22k2 Resistor
REL1 MT2 6V Relay
S1 SHA-2XWIS Switch
U200 LM324 Quad OPAMP
©1998 Audioscript BV
Version: 3-09-1998
23