Mod Nexus Series User manual

Phase / Off Copyright © 2023 by modelectronics.com
The Phase / O is a four-stage phaser based around the Sound Semiconductor SSI2140 voltage-controlled
multi-mode lter. This pedal oers classic phasing eects along with plenty of control to dial in the perfect
amount of modulation using the Depth,Rate, and Regen knobs. The Stages switch can change the Phase /
O from four-stage phaser to a two-stage phaser providing a wide variety of dierent phasing sounds.
Change the Mode switch from LFO to Manual to use the Phase / O in xed phase mode controlled by the
Depth knob for unique ltering eects.
The Phase / O pedal kit is the second entry in the Nexus Series from Mod®Electronics. This series
features a PCB base rather than the Mod®Electronics’ traditional point-to-point wiring kits to oer builders
an even wider variety of eects to build. The Phase / O is a great pedal for intermediate skill sets. It
features an all through-hole build with pre-soldered SMT SSI2140.
The pedal operates on 9VDC. A center negative power supply is required for use (not included with kit).
There is no battery connection. The pedal draws ~50mA. The enclosure size is a standard 1590BB (4.7" x
3.7" x 1.34").
PHASE/OFF
PHASE/OFF

Table of Contents
Phase / Off 1
Notes on PCB Construction
Parts Lists
PCB Bill of Materials
Applying The Sticker
Main PCB Construction
Footswitch PCB Construction
Jack PCB Construction
Final Assembly
Phase / O Controls
Schematic
2
3-7
8-11
12
13-18
19
20
21-23
24
25-27
Section Page
Required Tools
Adjustable Wrench
Cutters
Lead Formers
Needlenose Pliers
Phillips Head Screwdriver
Ruler
Small Flat Head Screwdriver
Solder
Soldering Iron
Wire Stripper
Xacto Knife or Similar Cutting Tool
Optional Recommended Tools
Anti-static Wrist Strap
Desoldering Braid
Desoldering Pump
Helping Hands
Multimeter
Oscilloscope
PCB Vise
Signal Generator
Tweezers

Phase / Off 2
Notes on PCB Construction
Lead Spacing
This section is intended for those unfamiliar or new to constructing circuit boards.
Components are made in two common mounting types, radial and axial. Radial
components feature leads that are parallel and oriented in the same direction
whereas the leads of axial components protrude from each end of the component
oriented in opposite directions.
These parts will have corresponding footprints on the PCB marked with text.
C_ designates a capacitor and R_ is used for resistors. The BOM will cover all
of the designators. Each footprint has a specic spacing. Footprints for the
radial parts will match the spacing of that part but axial parts require preparation
to t. For the resistors in this kit you can simply use your nger to push the lead
until it is perpendicular where the lead meets the part. Other axial parts will have
dierent lead spacings. Use a lead former tool on these parts.
Soldering
After inserting the PCB into its footprint, make sure that the component is sitting
ush against the PCB. Hold it in place and bend the leads on the opposite side of
the PCB away from the component. This will keep the component ush to the PCB
when soldering.
Make sure your soldering iron is fully warmed up before soldering. Position the
tip of the iron so that it is touching both the solder pad of the PCB and the
lead of the component. Slowly feed solder onto
the pad. The solder should ow evenly across
the pad and will slope up onto the component
lead. You may need to move the end of the solder
strand around the pad to ensure that the pad is fully
coated in solder and that it is also bonding to the lead.
Repeat this process for each lead of the component then
use a pair of cutters to snip the lead directly above the peak
of the solder.
Ideally the solder will ow through the pad hole and a small
amount will reach the opposite side of the PCB. This can
take some practice to master and is not critical. Focus on
consistently achieving full coverage of the pad with slight
slopes surrounding the lead rst.

R-N100
Main PCB Parts List
R-N200
100Ω 1/4W Metal Film Resistor
200Ω 1/4W Metal Film Resistor
Qty 2
Qty 4
Phase / Off 3
R-N47K
51KΩ 1/4W Metal Film Resistor
47KΩ 1/4W Metal Film Resistor
R-N51K
Qty 2
Qty 1
R-N13K 13KΩ 1/4W Metal Film Resistor
Qty 1
R-N16K 16KΩ 1/4W Metal Film Resistor
Qty 1
R-N18K 18KΩ 1/4W Metal Film Resistor
Qty 1
R-N33K 33KΩ 1/4W Metal Film Resistor
Qty 2
R-N100K
1MΩ 1/4W Metal Film Resistor
100KΩ 1/4W Metal Film Resistor
R-N1M
Qty 1
Qty 1
R-N1K 1KΩ 1/4W Metal Film Resistor
Qty 1
R-N3K 3KΩ 1/4W Metal Film Resistor
Qty 1
R-N5D1K 5.1KΩ 1/4W Metal Film Resistor
Qty 1
R-N8D2K 8.2KΩ 1/4W Metal Film Resistor
Qty 1
R-N10K 10KΩ 1/4W Metal Film Resistor Qty 15

P-Q971
Main PCB Parts List (cont.)
P-QLM311
LT1054 Voltage Converter IC, 8-Pin DIP
1N4148 Small Signal Diode
LM311 Comparator, 8-Pin DIP
P-QLT1054
Qty 2
Qty 1
Qty 1
Phase / Off 4
C-R82-1N 1nF Box Film Capacitor
Qty 4
C-D10P-50 10pF Ceramic Capacitor Qty 1
P-Q2N2222A-92 2N2222A NPN Transistor Qty 1
P-QTL074
8-Pin DIP Socket
TL074 Quad Op Amp IC, 14-Pin DIP
P-STIC-8
Qty 1
Qty 2
P-Q1N5817 1N5817 Schottky Diode Qty 1
C-R82-1N5 1.5nF Box Film Capacitor
Qty 1
C-R82-100N 100nF (.1uF) Box Film Capacitor Qty 1
C-R82-470N 470nF (.47uF) Box Film Capacitor Qty 2
TOP
DOWN
VIEW
TOP
DOWN
VIEW
TOP
DOWN
VIEW
TOP
DOWN
VIEW
TOP
DOWN
VIEW
C-D47P-50 47pF Ceramic Capacitor Qty 1
TOP
DOWN
VIEW
C-CD470-500 470pF Ceramic Capacitor Qty 1
TOP
DOWN
VIEW
C-D100N-50 100nF Ceramic Capacitor Qty 6
TOP
DOWN
VIEW
C-ETR100-25 100uF Electrolytic Capacitor Qty 3
TOP
DOWN
VIEW
TOP
DOWN
VIEW
14-Pin DIP Socket
P-STIC-14 Qty 1

Main PCB Parts List (cont.)
Phase / Off 5
P-H5411 SPDT Mini Toggle
Qty 1
BOTTOM
VIEW
TOP
DOWN
VIEW
TOP
DOWN
VIEW
TOP
DOWN
VIEW
P-H5410 DPDT Mini Toggle Qty 1
BOTTOM
VIEW
R-VAM10KA-SS-PCL A10KΩ 16mm PCB Mount Potentiometer Qty 1
R-VAM10KL-SS-PCL B10KΩ 16mm PCB Mount Potentiometer Qty 1
R-VAM50KL-SS-PCL B50KΩ 16mm PCB Mount Potentiometer Qty 1
K-905-PCB-MAIN Main PCB with presoldered SSI2140 IC Qty 1
S-W88-4-1 4 Conductor Flexstrip Ribbon Cable
Qty 1
S-W88-6-1 6 Conductor Flexstrip Ribbon Cable Qty 1
R-VCOVER-LP16 16mm Potentiometer Cover Qty 1
TOP
DOWN
VIEW

Phase / Off 6
R-G1K
Footswitch PCB Parts List
Black 24AWG Stranded Top Coat Wire
1KΩ 1/8W Metal Film Resistor
S-W3024TC-BK-50
Qty1
1ft
Jack PCB Parts List
P-L710-BLU Blue LED Lens
Qty 1
S-H534 1/4" Jack
Qty 2
S-W3024TC-W-50
Jack PCB
White 24AWG Stranded Top Coat Wire
K-905-PCB-JACK
1ft
Qty 1
P-L353 Blue 5mm Diused LED Schottky Diode Qty 1
P-H501-LP Low Prole 3PDT Footswitch
Qty 1
K-905-PCB-SWITCH Footswitch PCB
Qty 1
P-JBCL-EN-S DC Barrel Jack
Qty 1
TOP
DOWN
VIEW

Phase / Off 7
P-K371
Enclosure Parts List
Small Knob
Qty 1
P-K381 Large Knob
Qty 2
P-H1590BBCE Aluminum 1590BB Enclosure Qty 1
K-905-LABEL Phase / O Sticker Qty 1

Phase / Off 8
PCB BOMs
R1
R2
R3
R4
R5
R6
R7
R8
R9
R10
R11
R12
R13
R14
R15
10KΩ
200Ω
10KΩ
10KΩ
200Ω
10KΩ
33KΩ
10KΩ
5.1KΩ
33KΩ
10KΩ
10KΩ
13KΩ
8.2KΩ
100Ω
1/4W Metal Film Resistor
1/4W Metal Film Resistor
1/4W Metal Film Resistor
1/4W Metal Film Resistor
1/4W Metal Film Resistor
1/4W Metal Film Resistor
1/4W Metal Film Resistor
1/4W Metal Film Resistor
1/4W Metal Film Resistor
1/4W Metal Film Resistor
1/4W Metal Film Resistor
1/4W Metal Film Resistor
1/4W Metal Film Resistor
1/4W Metal Film Resistor
1/4W Metal Film Resistor
Part Value Type
Main PCB
SIDE 1 SIDE 2
R16 10KΩ 1/4W Metal Film Resistor
R17 200Ω 1/4W Metal Film Resistor
R18 10KΩ 1/4W Metal Film Resistor
R19 10KΩ 1/4W Metal Film Resistor
✔

Phase / Off 9
PCB BOMs
R27
R28
R29
R30
R31
R32
R33
R34
R35
D1
D2
D3
C1
C2
C3
10KΩ
10KΩ
18KΩ
10KΩ
1MΩ
3KΩ
100Ω
47KΩ
47KΩ
1N4148
1N4148
1N5817
1nF
1nF
470nF
1/4W Metal Film Resistor
1/4W Metal Film Resistor
1/4W Metal Film Resistor
1/4W Metal Film Resistor
1/4W Metal Film Resistor
1/4W Metal Film Resistor
1/4W Metal Film Resistor
1/4W Metal Film Resistor
1/4W Metal Film Resistor
1N4148 Small Signal Diode
1N4148 Small Signal Diode
1N5817 Schottky Diode
Film Capacitor
Film Capacitor
Film Capacitor
Main PCB (cont.)
C4 100nF Ceramic Capacitor
C5 47pF Ceramic Capacitor
C6 100uF Electrolytic Capacitor
C7 100uF Electrolytic Capacitor
R20
R21
R22
R23
R24
R25
R26
200Ω
10KΩ
16KΩ
1KΩ
100KΩ
51KΩ
10KΩ
1/4W Metal Film Resistor
1/4W Metal Film Resistor
1/4W Metal Film Resistor
1/4W Metal Film Resistor
1/4W Metal Film Resistor
1/4W Metal Film Resistor
1/4W Metal Film Resistor
Part Value Type ✔

Phase / Off 10
PCB BOMs
C15
C16
C17
C18
C19
C20
Q1
U1
U2
U3
U4
SW1
SW2
RV1
RV2
1.5nF
100nF
100nF
10pF
100uF
470nF
2N2222
SSI2140
LM311
TL074
LT1054
SPDT
DPDT
B10KΩ
A10KΩ
Film Capacitor
Ceramic Capacitor
Film Capacitor
Ceramic Capacitor
Electrolytic Capacitor
Film Capacitor
Electrolytic Capacitor
Sound Semi Multi-Mode VCF
DIP-8 High Speed Comparator
DIP-14 Quad Op Amp
DIP-8 Voltage Converter
2 Position SPDT Mini Toggle Switch
2 Position DPDT Mini Toggle Switch
16mm PCB Mount Potentiometer
16mm PCB Mount Potentiometer
Main PCB (cont.)
C8
C9
C10
C11
C12
C13
C14
100nF
100nF
100nF
100nF
1nF
1nF
470pF
Ceramic Capacitor
Ceramic Capacitor
Ceramic Capacitor
Ceramic Capacitor
Film Capacitor
Film Capacitor
Ceramic Capacitor
Part Value Type
✔
RV3 B50KΩ 16mm PCB Mount Potentiometer

Phase / Off 11
PCB BOMs
Input Jack
Output Jack
Ribbon Cable
Ground Wire
+9V Wire
1/4" Jack
1/4" Jack
4 Conductor
Black
Red
1/4" PCB Mount Jack
1/4" PCB Mount Jack
4 Conductor Flexstrip Ribbon
Pretinned 24AWG Wire
Pretinned 24AWG Wire
Jack PCB
SIDE 1 SIDE 2
Part Value Type ✔
Switch PCB
SIDE 1 SIDE 2
RLED
LED
Footswitch
Ribbon Cable
1KΩ
Blue
3PDT
6 Conductor
1/8W Metal Film Resistor
5mm Diused LED
Low Prole 3PDT Footswitch
6 Conductor Flexstrip Ribbon
Part Value Type ✔

Phase / Off 12
Applying The Sticker
Note: Do not apply the sticker until directed to do so at Step
73 in the instructions.
Locate the top of the pedal as well as the top of the sticker.
The cover of the instructions for your kit will have an image of
the pedal that can be used for reference.
Peel the backing from the sticker. Carefully line up the top
edge of the sticker with the top of the pedal. Press down to
apply the sticker only to the edge. Run a nger across the
edge to push any air out from beneath the sticker. Continue
this motion as you work your way down the pedal until the
sticker is fully attached.
Locate the holes beneath
the sticker and depress
them using a ngertip. Be
sure that the area of the
sticker surrounding the
holes is fully adhered to
the surface.
With an Xacto knife or
similar tool, carefully
pierce the sticker in the
center of each hole.
Carefully work the knife
from the center of the
hole to the edge and begin
cutting fully around the
edge until the sticker has
been fully cleared from
the hole.

Phase / Off 13
Main PCB Construction
Part 1: Resistors
Locate the Main PCB. The following steps will cover the placement and soldering of all parts that are
mounted on this PCB. Use the BOM and Parts List as references.
1: Insert a 10KΩ resistor at R1. Its color bands are
brown, black, black, red, brown.
2: Insert a 200Ω resistor at R2. Its color bands are
red, black, black, black, brown.
3: Insert a 10KΩ resistor at R3. Its color bands are
brown, black, black, red, brown.
4: Insert a 10KΩ resistor at R4. Its color bands are
brown, black, black, red, brown.
5: Insert a 200Ω resistor at R5. Its color bands are
red, black, black, black, brown. Solder these ve
resistors now.
6: Insert a 10KΩ resistor at R6. Its color bands are
brown, black, black, red, brown.
7: Insert a 33KΩ resistor at R7. Its color bands are
orange, orange, black, red, brown.
8: Insert a 10KΩ resistor at R8. Its color bands are
brown, black, black, red, brown.
9: Insert the 5.1KΩ resistor at R9. Its color bands are
green, brown, black, brown, brown.
10: Insert a 33KΩ resistor at R10. Its color bands are
orange, orange, black, red, brown. Solder these ve
resistors now.
11: Insert a 10KΩ resistor at R11. Its color bands are
brown, black, black, red, brown.
12: Insert a 10KΩ resistor at R12. Its color bands are
brown, black, black, red, brown.
13: Insert the 13KΩ resistor at R13. Its color bands are
brown, orange, black, red, brown.
14: Insert the 8.2KΩ resistor at R14. Its color bands are
gray, red, black, brown, brown.
15: Insert a 100Ω resistor at R15. Its color bands are
brown, black, black, black, brown. Solder these ve
resistors now.

Phase / Off 14
Main PCB Construction
Part 1: Resistors (cont.)
16: Insert a 10KΩ resistor at R16. Its color bands are
brown, black, black, red, brown.
17: Insert a 200Ω resistor at R17. Its color bands are
red, black, black, black, brown.
18: Insert a 10KΩ resistor at R18. Its color bands are
brown, black, black, red, brown.
19: Insert a 10KΩ resistor at R19. Its color bands are
brown, black, black, red, brown.
20: Insert a 200Ω resistor at R20. Its color bands are
red, black, black, black, brown. Solder these ve
resistors now.
21: Insert a 10KΩ resistor at R21. Its color bands are
brown, black, black, red, brown.
22: Insert a 16KΩ resistor at R22. Its color bands are
brown, blue, black, red, brown.
23: Insert a 1KΩ resistor at R23. Its color bands are
brown, black, black, brown, brown.
24: Insert the 100KΩ resistor at R24. Its color bands are
brown, black, black, orange, brown.
25: Insert a 51KΩ resistor at R25. Its color bands are
green, brown, black, red, brown. Solder these ve
resistors now.
26: Insert a 10KΩ resistor at R26. Its color bands are
brown, black, black, red, brown.
27: Insert a 10KΩ resistor at R27. Its color bands are
brown, black, black, red, brown.
30: Insert a 10KΩ resistor at R30. Its color bands are
brown, black, black, red, brown. Solder these ve
resistors now.
28: Insert a 10KΩ resistor at R28. Its color bands are
brown, black, black, red, brown.
29: Insert a 18KΩ resistor at R29. Its color bands are
brown, gray, black, red, brown.

39: Insert an 8-Pin DIP Socket at U2. Be sure to match
the orientation on the silkscreen. Solder this now.
40: Insert a 14-Pin DIP Socket at U3. Be sure to match
the orientation on the silkscreen. Solder this now.
41: Insert an 8-Pin DIP Socket at U4. Be sure to match
the orientation on the silkscreen. Solder this now.
42: Insert the 2N2222A transistor at Q1. Be sure to
match the orientation on the silkscreen. Solder this now.
Part 3: IC Sockets & Transistor
Phase / Off 15
Main PCB Construction
Part 1: Resistors (cont.)
31: Insert a 1MΩ resistor at R31. Its color bands are
brown, black, black, yellow, brown.
32: Insert a 3KΩ resistor at R32. Its color bands are
orange, black, black, brown, brown.
33: Insert a 100Ω resistor at R33. Its color bands are
brown, black, black, red, brown.
34: Insert a 47KΩ resistor at R34. Its color bands are
brown, black, black, red, brown.
35: Insert a 47KΩ resistor at R35. Its color bands are
red, black, black, black, brown. Solder these ve
resistors now.
Locate the three diodes. When inserting each diode,
note the orientation of the band. This should match
the orientation on the silkscreen.
36: Insert a 1N4148 diode at D1.
Part 2: Diodes
37: Insert a 1N4148 diode at D2.
38: Insert the 1N5817 diode at D3. Solder these three
diodes now.

Phase / Off 16
Main PCB Construction
Part 4: Capacitors
52: Insert a 100nF ceramic capacitor at C10. This is the
circular capacitor marked 104.
53: Insert a 100nF ceramic capacitor at C11. This is the
circular capacitor marked 104.
56: Insert a 470pF ceramic capacitor at C14. This is the
circular capacitor marked 471. Solder these ve
capacitors now.
54: Insert a 1nF lm capacitor C12. This is the
rectangular capacitor marked 1nJ100.
55: Insert a 1nF lm capacitor at C13. This is the
rectangular capacitor marked 1nJ100.
48: Insert a 100uF electrolytic capacitor at C6. When
inserting the capacitor, note the orientation of the
positive and negative lead.
51: Insert a 100nF ceramic capacitor at C9. This is the
circular capacitor marked 104. Solder these four
capacitors now.
50: Insert a 100nF ceramic capacitor at C8. This is the
circular capacitor marked 104.
49: Insert a 100uF electrolytic capacitor at C7. When
inserting the capacitor, note the orientation of the
positive and negative lead.
43: Insert a 1nF lm capacitor at C1. This is the
rectangular capacitor marked 1nJ100.
44: Insert a 1nF lm capacitor at C2. This is the
rectangular capacitor marked 1nJ100.
47: Insert a 47pF ceramic capacitor at C5. This is the
circular capacitor marked 47. Solder these ve
capacitors now.
45: Insert a 470nF lm capacitor at C3. This is the
rectangular capacitor marked .47K63.
46: Insert a 100nF ceramic capacitor at C4. This is the
circular capacitor marked 104.
104
47

Phase / Off 17
Main PCB Construction
Part 4: Capacitors (cont.)
62: Insert a 470nF lm capacitor at C20. This is the
rectangular capacitor marked .47K63. Solder this
capacitor now.
57: Insert a 1.5nF lm capacitor at C15. This is the
rectangular capacitor marked 1n5K100.
58: Insert a 100nF ceramic capacitor at C16. This is the
circular capacitor marked 104.
61: Insert a 100uF electrolytic capacitor at C19. When
inserting the capacitor, note the orientation of the
negative lead. Solder these ve capacitors.
59: Insert a 100nF lm capacitor at C17. This is the
rectangular capacitor marked .1J100.
60: Insert a 10pF ceramic capacitor at C18. This is the
circular capacitor marked 10.

Phase / Off 18
Main PCB Construction
64: Remove all of the mounting hardware and insert
the DPDT mini toggle switch at SW2 on side 2 of the
PCB. Don't solder these switches yet but make sure
they are both fully inserted through the PCB.
65: Locate the 3 potentiometers and remove all mounting hardware.
Grip the small metal tab on each pot with a pair of pliers and gently
rock the tab until it snaps o.
66: Slide the plastic cover onto the B10K
potentiometer.
69: Attach and tighten the mounting hardware
for both the switches and pots now. Use a single
nut for the switches. Make sure the pots remain
aligned and don't twist as you tighten the nut.
This hardware only needs to be nger tight for
now.
63: Remove all of the mounting hardware and insert
the SPDT mini toggle switch at SW1 on side 2 of the
PCB.
Part 5: Switches and Potentiometers
67: Locate the enclosure and mount the 3 pots
as shown. Use the mounting hardware to hold
each pot onto the enclosure but keep them
loose enough to rotate.
68: Take the main PCB and delicately mount it
to the enclosure by gently sliding the toggle
switches through the two holes to the left and
right of the B10K pot. As the toggles' bushings
slide through the holes carefully guide the pots'
pins into their mounting holes.
70: Make sure that the PCB is still ush to the
switches. Solder both switches and all three
pots now. Remove the mounting hardware and
carefully remove the PCB from the enclosure.

Phase / Off 19
Footswitch PCB Construction
Mount All Components
Locate the Footswitch PCB. The following steps will cover the placement and soldering of all parts
that are mounted on this PCB. Use the BOM and Parts List as references.
72: Insert the 3PDT footswitch into the 9 pin footprint on side 2 of the PCB. Solder
the footswitch to the PCB.
75: Remove the mounting hardware from the
3PDT footswitch. Carefully guide the LED leads through the LED + and LED - holes
while inserting the footswitch bushing through the footswitch mounting hole
at the bottom of the enclosure. The positive lead goes through the LED + hole
and the negative lead goes through the LED - hole. When fully inserted, slide
the metal at washer over the bushing of the footswitch, then use the nut to
secure the footswitch to the chassis. Finger tight will be good enough. Once
secured, check to make sure the LED leads are straight, that the LED is fully
inserted into the lens, and that the lens is ush to the exterior of the
enclosure. Solder the LED to the PCB.
76: Once soldered, snip the excess LED leads from the pcb. Loosen the
footswitch's mounting hardware and carefully remove the PCB from the
enclosure. Be extra careful to avoid bending the LED leads.
71: Insert the 1/8W 1KΩ resistor at RLED. Its color bands are brown, black, black,
brown, brown. Solder the RLED resistor to the PCB.
73: Apply the sticker to the enclosure now. See page 12 for instructions.
74: Once the sticker is completed, insert the LED lens into the small hole directly
next to the large footswitch hole. Some force may be required. Slide the LED into the lens. The LED
will lightly snap into place when fully inserted. Orient the LED so that the positive lead (longer lead)
is on the bottom side of the enclosure and the negative lead (shorter lead) is on the top side when
viewed from below.