aion OSIRIS User manual

OSIRIS DISTORTION/SUSTAINER 1
PROJECT NAME
OSIRIS
BASED ON
EFFECT TYPE
PROJECT SUMMARY
DOCUMENT VERSION
Black Arts Toneworks Pharaoh
Based on the classic Big Muff circuit, this pedal adds a high/low impedance switch, a diode selector
switch, and a high-end control inside the tone stack.
Distortion / Sustainer, Fuzz 1.0.0 (2019-03-14)
Actual size is 2.3” x 1.86” (main board) and 1.79” x 0.86” (bypass board).
BUILD DIFFICULTY
Easy

OSIRIS DISTORTION/SUSTAINER 2
TABLE OF CONTENTS
1Project Overview 7Enclosure Layout
2Introduction & Usage 8Wiring Diagram
3-4 Parts List 9Licensing
5Schematic 9Document Revisions
6Drill Template
INTRODUCTION
The Osiris Distortion/Sustainer is adapted from the Black Arts Toneworks Pharaoh Fuzz, a Big Muff-
based circuit with a few modifications.
First, an input impedance switch has been added to the front of the circuit. By reducing the signal level
before the boost and clipping stages, you can match it to high-output instruments or earlier pedals in the
chain, or just reduce the overall signal level for more headroom and less clipping.
Second, a clipping switch has been added to control has been added to go between silicon and
germanium diodes in the second clipping stage. The silicon diodes are in the stock Big Muff for a familiar
sound, while germaniums will be more compressed and gainy, but also softer with a more rounded
clipping waveform.
Third, a “High” control has been added to the bass side of the tone control rotation allowing the low-pass
filter frequency to be adjusted. This restores some of the high end so you don’t have to choose between
a bass emphasis and treble emphasis.
USAGE
The Osiris has the following controls:
• Hi/Lo toggles between two different resistors on the input, which changes the amount of headroom
and clipping later in the circuit.
• Si/Ge toggles between silicon (stock) diodes and asymmetrical germanium diodes.
• Sustain controls the amount of drive or distortion, which also affects the amount of sustain.
• Tone is a the classic Big Muff balance control with a high-pass filter (treble emphasis) on one side
and a low-pass filter (bass emphasis) on the other.
• High allows you to vary the low-pass filter cutoff point on the bass side of the tone control,
restoring some of the high-end signal on the bass settings.
• Volume is the overall output.

OSIRIS DISTORTION/SUSTAINER 3
PARTS LIST
This parts list is also available in a spreadsheet format which can be imported directly into Mouser for
easy parts ordering. Mouser doesn’t carry all the parts (most notably potentiometers) so the second tab
lists all the non-Mouser parts as well as sources for each.
View parts list spreadsheet →
PART VALUE TYPE NOTES
R1 39k Metal film resistor, 1/4W
R2 390k Metal film resistor, 1/4W
R3 100k Metal film resistor, 1/4W
R4 470k Metal film resistor, 1/4W
R5 1k Metal film resistor, 1/4W
R6 10k Metal film resistor, 1/4W
R7 1k Metal film resistor, 1/4W
R8 6k2 Metal film resistor, 1/4W
R9 100k Metal film resistor, 1/4W
R10 470k Metal film resistor, 1/4W
R11 100R Metal film resistor, 1/4W
R12 10k Metal film resistor, 1/4W
R13 6k2 Metal film resistor, 1/4W
R14 100k Metal film resistor, 1/4W
R15 470k Metal film resistor, 1/4W
R16 100R Metal film resistor, 1/4W
R17 10k Metal film resistor, 1/4W
R18 470k Metal film resistor, 1/4W
R19 470k Metal film resistor, 1/4W
R20 100k Metal film resistor, 1/4W
R21 10k Metal film resistor, 1/4W
R22 2k2 Metal film resistor, 1/4W
R23 47R Metal film resistor, 1/4W
RPD 2M2 Metal film resistor, 1/4W Input pulldown resistor. Can be as low as 1M.
LEDR 4k7 Metal film resistor, 1/4W LED current-limiting resistor. Adjust value to change LED brightness.
C1 1uF Film capacitor, 7.2 x 3.5mm
C2 470pF MLCC capacitor, NP0/C0G
C3 470n Film capacitor, 7.2 x 3mm
C4 47n Film capacitor, 7.2 x 2.5mm
C5 470pF MLCC capacitor, NP0/C0G

OSIRIS DISTORTION/SUSTAINER 4
PARTS LIST, CONT.
PART VALUE TYPE NOTES
C6 47n Film capacitor, 7.2 x 2.5mm
C7 47n Film capacitor, 7.2 x 2.5mm
C8 470pF MLCC capacitor, NP0/C0G
C9 47n Film capacitor, 7.2 x 2.5mm
C10 10n Film capacitor, 7.2 x 2.5mm
C11 22n Film capacitor, 7.2 x 2.5mm
C12 47n Film capacitor, 7.2 x 2.5mm
C13 1uF Film capacitor, 7.2 x 3.5mm
C14 100uF Electrolytic capacitor, 6.3mm Power supply filter capacitor.
C15 100n MLCC capacitor, X7R Power supply filter capacitor.
D1 1N5817 Schottky diode, DO-41
D2 1N914 Fast-switching diode, DO-35
D3 1N914 Fast-switching diode, DO-35
D4 1N914 Fast-switching diode, DO-35
D5 1N914 Fast-switching diode, DO-35
D6 1N34A Germanium diode Exact part number is unimportant. Any germanium should work here.
D7 1N34A Germanium diode Exact part number is unimportant. Any germanium should work here.
D8 1N34A Germanium diode Exact part number is unimportant. Any germanium should work here.
Q1 MPSA18 BJT transistor, NPN, TO-92
Q2 2N5089 BJT transistor, NPN, TO-92
Q3 2N5089 BJT transistor, NPN, TO-92
Q4 2N5089 BJT transistor, NPN, TO-92
HI-LO SPDT Toggle switch, SPDT on-on
SI-GE SPDT Toggle switch, SPDT on-on
FUZZ 100kB 16mm right-angle PCB mount pot
HIGH 25kB 16mm right-angle PCB mount pot
TONE 250kB 16mm right-angle PCB mount pot
VOL. 100kA 16mm right-angle PCB mount pot
IN 1/4" stereo 1/4" phone jack, closed frame Switchcraft 112BX or equivalent.
OUT 1/4" mono 1/4" phone jack, closed frame Switchcraft 111X or equivalent.
DC 2.1mm DC jack, 2.1mm panel mount Mouser 163-4302-E or equivalent.
BATT Battery snap 9V battery snap Optional. Use the soft plastic type—the hard-shell type will not fit.
FSW 3PDT Stomp switch, 3PDT
ENC 125B Enclosure, die-cast aluminum Can also use a Hammond 1590N1.

SCHEMATIC
OSIRIS DISTORTION/SUSTAINER 5
GND
2M2
1N5817
100uF
GND
25kB
+9V
100n
VA
GND GND GND GND GNDGND GND GNDGND GNDGND GND
390k
100k
470k
1k 10k 1k
6k2
100k
470k
100R 10k
6k2
100k
470k
100R 10k
470k
470k100k
10k2k2
1uF
470pF
470n
47n
470pF
47n
47n
470pF
47n
10n
22n
47n
1uF
MPSA18 2N5089 2N5089
2N5089
100kB
250kB 100kA
VA
VA
VA
VA
VA
1N914
1N914
1N914
1N914
47R
39k
RPD
D1
C14
HIGH
1
2
3
IN
OUT
C15
R2
R3
R4
R5 R6
R7
R8
R9
R10
R11 R12
R13
R14
R15
R16 R17 R18
R19R20
R21R22
C1
C2
C3
C4
C5
C6
C7
C8
C9
C10
C11
C12
C13
Q1 Q2 Q3
Q4
FUZZ
1
2
3
TONE
1
2
3
VOLUME
1
2
3
D2
D3
D4
D5
R23
HI-LO
2
3
1
SI-GE
2
3
1
R1
D6
D7D8
GND

OSIRIS DISTORTION/SUSTAINER 6
DRILL TEMPLATE
Cut out this drill template, fold the edges and tape it to the enclosure. Before drilling, it’s recommended
to first use a center punch for each of the holes to help guide the drill bit.
Ensure that this template is printed at 100% or “Actual Size”. You can double-check this by measuring
the scale on the printed page.
Top jack layout assumes the use of closed-frame jacks like the Switchcraft 111X. If you’d rather use
open-frame jacks, please refer to the Open-Frame Jack Drill Template for the top side.
LED hole drill size assumes the use of a 5mm LED bezel, available from several parts suppliers. Adjust
size accordingly if using something different, such as a 3mm bezel, a plastic bezel, or just a plain LED.
0 1 2
CM
0 1
INCH
x: -0.775, y: +1.71 x: +0.775, y: +1.71
ø9/32” ø9/32”
x: -0.775, y: +0.41
ø9/32”
x: 0, y: +1.06
ø1/4”
x: 0, y: +0.41
ø1/4”
x: +0.775, y: +0.41
ø9/32”
x: 0, y: -1.20
ø15/32”
x: -0.775, y: -1.20
ø5/16”
CENTER (0,0)
125B
TONE
SI-GE
HIGH
FUZZHI-LOVOLUME
FOOTSWITCHLED
ø3/8” ø1/2”
0.385”
0.625” 0.625”
ø3/8”
OUT DC IN

OSIRIS DISTORTION/SUSTAINER 7
ENCLOSURE LAYOUT
Enclosure is shown without jacks. See next page for jack layout and wiring.
125B

OSIRIS DISTORTION/SUSTAINER 8
WIRING DIAGRAM
125B
IN +VGND N.C. N.C. OUT
PCB
IN
GND +V +V JACK GND JACK
OUTIN
GND GND PCB
OUT
Shown with optional 9V battery. If battery is omitted, both jacks can be mono rather than one being stereo.
Leave the far-right lug of the DC jack unconnected.

OSIRIS DISTORTION/SUSTAINER 9
LICENSE & USAGE
No direct support is offered for these projects beyond the provided documentation. It’s assumed
that you have at least some experience building pedals before starting one of these. Replacements and
refunds cannot be offered unless it can be shown that the circuit or documentation are in error.
All of these circuits have been tested in good faith in their base configurations. However, not all the
modifications or variations have necessarily been tested. These are offered only as suggestions based
on the experience and opinions of others.
Projects may be used for commercial endeavors in any quantity unless specifically noted. No
attribution is necessary, though a link back is always greatly appreciated. The only usage restrictions
are that (1) you cannot resell the PCB as part of a kit without prior arrangement, and (2) you cannot
“goop” the circuit, scratch off the screenprint, or otherwise obfuscate the circuit to disguise its source.
(In other words: you don’t have to go out of your way to advertise the fact that you use these PCBs, but
please don’t go out of your way to hide it. The guitar effects industry needs more transparency, not less!)
DOCUMENT REVISIONS
1.0.0 (2019-03-14)
Initial release.