Oakley 5U User manual

Oakley Sound Systems
5U Oakley Modular Series
MOSPhaser
Voltage Controlled Phaser
PCB Issue 1
Builder's Guide
V1.5
Tony Allgood
Oakley Sound Systems
CARLISLE
United Kingdom

The 1U wide panel design for the MOSPhaser for MOTM format systems. The fpd file for this panel can
be found on the project webpage.
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Introduction
This is the Pro ect Builder's Guide for the issue 1 MOSPhaser 5U module from Oakley Sound.
This document contains a basic introduction to the board, a full parts list for the components
needed to populate the boards, and a list of the various interconnections.
The main pro ect webpage can be found at:
http://www.oakleysound.com/MOSPhaser.htm
For general information regarding where to get parts and suggested part numbers please see
our useful Parts Guide at the pro ect webpage or http://www.oakleysound.com/parts.pdf.
For general information on how to build our modules, including circuit board population,
mounting front panel components and making up board interconnects please see our generic
Construction Guide at the pro ect webpage or http://www.oakleysound.com/construct.pdf.
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The MOSPhaser PCB
This is the issue 1 Oakley MOSPhaser behind a natural finish Schaeffer panel. ote the use of the
optional Sock4 socket board to facilitate the wiring up of the sockets.
I have provided space for the four main control pots on the PCB. If you use the specified
16mm Alpha pots and matching brackets, the PCB can be held firmly to the panel without any
additional mounting procedures. The pot spacing is 1.625” and is the same as the vertical
spacing on the MOTM modular synthesiser and most of our other modules.
The design requires plus and minus 15V supplies. The power supply should be adequately
regulated. The current consumption is about 35mA for each rail. Power is routed onto the
PCB by a four way 0.156” MTA156 type connector or the special five way Synthesizers.com
MTA100 header. You could, of course, wire up the board by soldering on wires directly. The
four pins are +15V, ground, earth/panel ground, -15V. The earth/panel connection allows you
to connect the metal front panel to the power supply’s ground without it sharing the modules’
ground line. More about this later.
The PCB has four mounting holes for M3 bolts, one near each corner. These are not required
if you are using the three 16mm pot brackets.
The board size is 143mm (high) x 77mm (deep).
The board has been laid out to accept connection to our Sock4 socket board. This small board
speeds up the wiring of the eight sockets and reduces the chances of mistakes.
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Issue 1 MOSPhaser Parts List
For general information regarding where to get parts and suggested part numbers please see
my useful Parts Guide at the pro ect webpage or http://www.oakleysound.com/parts.pdf.
The components are grouped into values, the order of the component names is of no particular
consequence.
A quick note on European part descriptions. R is shorthand for ohm. K is shorthand for kilo-
ohm. So 22R is 22 ohm, 1K5 is 1,500 ohms or 1.5 kilohms. For capacitors: 1uF = one
microfarad = 1000nF = one thousand nanofarad.
To prevent loss of the small ‘.’ as the decimal point, a convention of inserting the unit in its
place is used. eg. 4R7 is a 4.7 ohm, 4K7 is a 4700 ohm resistor, 6n8 is a 6.8 nF capacitor.
esistors
1% 0.25W metal film types are recommended.
22R R53, R48
100R R47, R49
220R R20
470R R33
510R R5, R30
1K R22, R23, R57, R58, R50, R59
1K +3000ppm/K R2
2K2 R3, R14, R8
3K3 R34
4K7 R36, R39, R4, R42, R46, R43, R26, R44, R17, R24, R25, R37, R35,
R16
10K R18, R29
22K R40
33K R1, R27, R55
47K R51, R52
82K R41
100K R31, R54, R13, R9, R6, R21, R56
220K R32, R19, R38, R45, R28
270K R11
360K R15
680K R10, R12
R7 is not fitted and the space is left empty.
R2 is a positive temperature coefficient resistor with a nominal value of 1K and temp. co. of
anywhere between +3000ppm/K and 3900ppm/K. Alternatively, it can be a standard 1K
resistor if you don't mind a small amount of temperature dependant drift in the centre
frequency of the phaser.
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Trimmer
100K trimmer (eg. Bourns 3386F) TUNE
Potentiometers
All pots Alpha 16mm PCB mounted types.
10K linear or reverse log FEEDBACK
50K linear FREQUENCY, MOD_DEPTH
50K log LFO_RATE
Three 16mm pot brackets.
Capacitors
100nF axial multilayer ceramic C20, C7, C3, C16, C22, C12, C14, C10, C6, C5, C1,
C26
100pF 2.5mm C0G ceramic C21
470pF 2.5mm C0G ceramic C13, C8, C4
1nF, 100V polyester C27
47nF, 63V polyester C18, C17, C9, C25, C19, C24
100nF, 63V polyester C11
470nF, 63V polyester C2, C15
1uF, 50V polyester C23, C30
2u2, 63V electrolytic C28, C31
22uF, 35V electrolytic C32, C29
Discrete Semiconductors
1N4148 signal diode D1, D2
5V1 zener diode D3
BAT42 Schottky diode D4
BC550 NPN transistor Q1, Q2
Bi-colour 5mm LED LED – not fitted directly to board
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Integrated Circuits
CD4009UBE* CMOS hex inverter U4
TL072CP U1, U2, U3, U5, U6, U7
TL074CN U8
* The HCF4009UBE may also be used.
The 4009UBE is easily damaged with static discharge. Take special care when handling this
device. IC sockets are not necessary but I would advise using a 16-pin DIL socket for U4.
Miscellaneous
Leaded axial ferrite beads L1, L2
MTA156 4 way header PSU – Oakley/MOTM power supply
MTA100 6-way header PWR – Synthesizers.com power supply
Molex/MTA 0.1” header 8-way I/O – for connecting to sockets
Molex/MTA 0.1” housing 8-way I/O – for connecting to sockets
3 way 0.1” header INV
0.1” umper For fitting to INV
Molex/MTA 0.1” housing 2-way LED (optional connecting technique for the LED)
5mm clear LED lens LED
5mm LED lens securing ring LED (if lens is not self securing)
Switchcraft 112APC 1/4” sockets Four off mounted either on the Sock4 board or on panel
Four knobs
Around 2m of insulated multistrand hook up wire.
Components required if using optional Sock4 board
Molex/MTA 0.1” header 8-way I/O (mounted on reverse side of PCB)
Molex/MTA 0.1” housing 8-way I/O
112APC Switchcraft 1/4” socket SK1, SK2, SK3, SK4
A single wire link is to be fitted to L2 on the Sock4 PCB. L1 is left open.
If using Molex KK you'll also need at least 16 crimp terminals.
Suitable lengths of wire to make up the single 100mm interconnect and two cable ties.
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Connections
Power connections – MOTM and Oakley
The PSU power socket is 0.156” Molex/MTA 4-way header. Friction lock types are
recommended. This system is compatible with MOTM systems.
Power Pin number
+15V 1
Module GND 2
Earth/PAN 3
-15V 4
Pin 1 on the I/O header has been provided to allow the ground tags of the ack sockets to be
connected to the power supply ground without using the module’s 0V supply. Earth loops
cannot occur through patch leads this way, although screening is maintained. Of course, this
can only work if all your modules follow this principle.
Power connections – Synthesizers.com
The PWR power socket is to be fitted if you are using the module with a Synthesizers.com
system. In this case you should not fit the PSU header. The PWR header is a six way 0.1”
MTA, but with the pin that is in location 2 removed. In this way location 3 is actually pin 2 on
my schematic, location 4 is actually pin 5 and so on.
Power Location number Schematic Pin number
+15V 1 1
Missing Pin 2
+5V 3 2
Module GND 4 3
-15V 5 4
Not connected 6 5
+5V is not used on this module, so location 3 (pin 2) is not actually connected to anything on
the PCB.
If fitting the PWR header, you will also need to link out pins 2 and 3 of PSU. This connects
the panel ground with the module ground. Simply solder a solid wire hoop made from a
resistor lead clipping to oin the middle two pads of PSU together.
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Building the MOSPhaser module using the Sock4 board
This is the simplest way of connecting all the sockets to the main board. The Sock4 board
should be populated in the way described in our construction guide found on the pro ect
webpage. There is only one eight way header and it is to be fitted to the bottom side of the
board.
Do not forget to solder in the wire link L2. Link L1 is left open.
You need to make up only one eight way interconnect. It should be made so that it is 100mm
long.
The prototype unit showing the detail of the board to board interconnect. Here I have used the Molex KK
0.1” system to connect the Sock4 to the main PCB.
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Hand wiring the sockets
If you have bought Switchcraft 112A sockets you will see that they have three connections.
One is the earth or ground tag. One is the signal tag which will be connected to the tip of the
ack plug when it is inserted. The third tag is the normalised tag, or NC (normally closed) tag.
The NC tag is internally connected to the signal tag when a ack is not connected. This
connection is automatically broken when you insert a ack.
Once fitted to the front panel the ground tags of each socket can be all connected together
with solid wire. I use 0.91mm diameter tinned copper wire for this ob. It is nice and stiff, so
retains its shape. A single piece of insulated wire can then be used to connect those connected
earth tags to pin 1 of I/O. Pin 1 is the square solder pad.
All the other connections are connected to the signal or NC lugs of the sockets. The tables
below show the connections you need to make:
Pin Pad name Socket Connection Lug Type
Pin 1 PANEL_GND Connect to all sockets Earth lugs
Pin 2 LFO_OUT Connect to LFO OUT Signal lug
Pin 3 NC No connection
Pin 4 AUDIO_OUT Connect to AUDIO OUT Signal lug
Pin 5 NC_LFO Connect to CV IN NC lug
Pin 6 CV_IN Connect to CV IN Signal lug
Pin 7 GND Connect to AUDIO IN NC lug
Pin 8 AUDIO_IN Connect to AUDIO IN Signal lug
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Wiring the LED
The Oakley MOSPhaser has one LED which is held in place on the panel with a LED lens and
clip. These are wired to the main board in similar fashion to other Oakley 5U modules.
Using a two way Molex KK housing to connect the bi-colour LED to the circuit board. The LED is held
onto the panel with a clear Cliplite lens, or equivalent.
Bi-colour LEDs have ust two legs and each one should go to the solder pad directly beneath
it when it is mounted into the panel. I normally wire it up so that the LED goes red when the
non inverted output is positive.
You can either solder your connecting wires to the LED's legs or use a MTA or Molex
connector to make the connection.
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Testing
Apply power to the unit making sure you are applying the power correctly. Check that no
device is running hot. Any sign of smoke or strange smells turn off the power immediately and
recheck the polarity of the power supply, and the direction of the ICs in their sockets and the
polarity of the electrolytic capacitors.
The unit should take no more than around 35mA from the +15V and the -15V power rails.
The LED should be lighting up and moving from red to green continuously. If it doesn’t turn
off, and check all the parts again thoroughly. If your LED is OK, and there is no smoke rising
from the board, then try the LFO Rate control. It should control the LED’s flashing. From
around one cycle every 70 seconds to around 8 cycles a second.
Now input an audio signal of some sort, any will do, but a simple sawtooth wave at around
220Hz is quite sufficient. Listen to the audio output, and play with the controls. With all
controls to the minimum setting, sweep the FREQUENCY pot. Do you hear the characteristic
phase sweep? If not, you have got a problem. If yes, now turn up the EMPHASIS. Using the
frequency pot again, does the sweep have a more metallic ring to it.
Now set the frequency and emphasis pots to their middle position. Turn up the
MODULATION DEPTH. The LFO should now be modulating the phaser. Check that the
LFO RATE control affects the speed of the modulation.
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Calibration
Apply power to module and allow to warm up for a few minutes. Turn the Frequency and
modulation controls to their minimum positions.
Measure the voltage across zener diode D3 – which is to the right of U4, the 4009UBE.
Ad ust the trimmer labelled TUNE so that the voltage across D3 reads 0.75V.
There is one trimmer on the MOSPhaser board. This is a Bourns 3386F.
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The Low Frequency Oscillator Output
The internal LFO circuit produces a triangle wave output of approximately +/-5V which is
also available from a dedicated front panel socket. This allows you to use the MOSPhaser's
internal LFO for other modulation purposes. The LFO's output signal is automatically routed
to the modulation depth pot when no ack is inserted in the CV input.
The LFO OUT socket can be configured as normal or inverted. In normal mode the LFO
output is in phase and is simply a copy of the signal being sent to the phaser circuitry. That is
the voltage output from the LFO OUT socket rises as the phaser frequency moves upwards.
In inverted mode the LFO output is an inverted signal. Thus when the phaser is being swept
upwards, the LFO OUT signal is going downwards. The mode is selected by the position of a
movable umper found at the lower edge of the circuit board. The position of the umper does
not affect the polarity of any CV IN signal.
When the umper is fitted across the two pins nearest the front panel the output from LFO
OUT is inverted. When the umper is fitted across the two pins furthest from the front panel
the signal from LFO OUT is in phase with the internal modulation. If no umper is fitted the
LFO OUT socket will not produce any signal.
By having two MOSPhaser modules you can use one to modulate the other. Simply connect
the LFO OUT of one (the master) to the CV IN of the other (the slave). You can now
modulate both phasers with the master's LFO. If the LFO mode is set to non inverting this will
allow for true stereo phasing, whereby both channels are treated equally. With mode set to
invert then you will create a form of stereo phase panning, where each phaser moves in an
opposite direction to give a wide stereo effect.
Here we can see the three pin header and two way jumper that selects the LFO mode. In the position
shown in the photograph the LFO OUT will produce an inverted signal.
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Final Comments
If you have any problems with the module, an excellent source of support is the Oakley Sound
Forum at Muffwiggler.com. I am on this group, as well as many other users and builders of
Oakley modules.
If you can't get your pro ect to work and you are in the EU, then Oakley Sound Systems are
able to offer a 'get you working' service. If you wish to take up this service please e-mail me,
Tony Allgood, at my contact e-mail address found on the website. I can service either fully
populated PCBs or whole modules. You will be charged for all postage costs, any parts used
and my time at 25GBP per hour. Most faults can be found and fixed within one hour, and I
normally return modules within a week. The minimum charge is 25GBP plus return postage
costs.
If you have a comment about this builder's guide, or have a found a mistake in it, then please
do let me know. But please do not contact me directly with questions about sourcing
components or general fault finding. Honestly, I would love to help but I do not have the time
to help everyone individually by e-mail.
Last but not least, can I say a big thank you to all of you who helped and inspired me. Thanks
especially to all those nice people on the Synth-diy and Analogue Heaven mailing lists and
those at Muffwiggler.com.
Tony Allgood at Oakley Sound
Cumbria, UK
© March 2018
No part of this document may be copied by whatever means without my permission.
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