aion Gladiator Dual Drive User manual

GLADIATOR DUAL DRIVE 1
PROJECT NAME
GLADIATOR
BASED ON
EFFECT TYPE
PROJECT SUMMARY
DOCUMENT VERSION
King Tone Duellist
A popular dual-channel overdrive first released in 2015 that combines a stripped-down Tube Screamer
with a hot-rodded Bluesbreaker.
Dual-channel overdrive 1.0.1 (2022-05-23)
BUILD DIFFICULTY
Intermediate
Actual size is 4.4” x 1.52” (main board) and 4.00” x 0.74” (bypass board).

GLADIATOR DUAL DRIVE 2
TABLE OF CONTENTS
1Project Overview 8Drill Template
2Introduction & Usage 9Enclosure Layout
3-5 Parts List 10 Wiring Diagram
6Build Notes 11 Wiring Diagram (no send/return loop)
7Schematic 12 Licensing & Document Revisions
INTRODUCTION
The Gladiator Dual Overdrive is based on the King Tone Duellist, a highly prized dual pedal first released
in 2015 consisting of the “String Singer” for side A and the “Heavy Hand” for side B. The Duellist was
traced by Aion FX in 2022.
The String Singer is based on a stripped-down Tube Screamer with input & output buffers removed. The
circuit is highly modified, so the EQ and clipping will sound drastically different from the classic Ibanez
circuit, but that was the source at least. This half of the circuit was released in single-pedal format as the
Soloist, available from Aion FX as the Gladius.
The Heavy Hand is based on the Marshall Bluesbreaker, but again it has been heavily modified from the
original circuit—so it may remind you of it, but it’s not going to sound quite the same. This half of the was
also released as a single pedal called the Heavyhand, available from Aion FX as the Xiphos.
Each side also has an external “EQ” toggle switch to select between different EQ voicings, as well as two
internal DIP switches for fat EQ and asymmetrical clipping (side A) or and asymmetrical clipping and
hard clipping (side B).
The Gladiator simplifies the send/return functionality of the original unit by including 4 jacks by default.
The send & return now have their own jacks that automatically short together if nothing is plugged in.
Otherwise, the Gladiator is a direct clone of the Duellist based on our own trace. Details are available in
the tracing journal on our website.
USAGE
The Gladiator has four external controls per channel:
• Drive controls the amount of gain going into the op-amp feedback diode clipping stage.
• Tone controls the treble response of the channel via a passive filter.
• Volume controls the overall output of the channel.
• EQ (toggle) selects between Fat (more bass), Stock (balanced), and Glass (more treble) modes.
In addition, each channel has two internal controls by way of DIP switches:
• Asymmetric (both channels) adds a clipping diode in series. Engaged when DIP switch is off.
• Warmth (side A only) adds an extra treble-cut capacitor. Engaged when DIP switch is on.
• Hard Clip (side B only) enables the hard clipping diodes. Engaged when DIP switch is off.

GLADIATOR DUAL DRIVE 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—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 1M Metal film resistor, 1/4W
R2 47k Metal film resistor, 1/4W
R3 4k7 Metal film resistor, 1/4W
R4 3k3 Metal film resistor, 1/4W
R5 20k Metal film resistor, 1/4W
R6 1k Metal film resistor, 1/4W
R7 220R Metal film resistor, 1/4W
R8 10k Metal film resistor, 1/4W
R9 1k Metal film resistor, 1/4W
R10 47k Metal film resistor, 1/4W
R11 47k Metal film resistor, 1/4W
R12 1M Metal film resistor, 1/4W
R13 133k Metal film resistor, 1/4W
R14 30k1 Metal film resistor, 1/4W
R15 28k7 Metal film resistor, 1/4W
R16 4k7 Metal film resistor, 1/4W
R17 10k Metal film resistor, 1/4W
R18 220k Metal film resistor, 1/4W
R19 5k6 Metal film resistor, 1/4W
R20 1k Metal film resistor, 1/4W
R21 9k53 Metal film resistor, 1/4W
R22 47k Metal film resistor, 1/4W
R23 47k Metal film resistor, 1/4W
R24 100R Metal film resistor, 1/4W Power supply filter resistor.
R25 100R Metal film resistor, 1/4W Power supply filter resistor.
R29 4k7 Metal film resistor, 1/4W LED current-limiting resistor (Ch. A) which affects LED brightness.
R30 4k7 Metal film resistor, 1/4W LED current-limiting resistor (Ch. B) which affects LED brightness.
RPD1 2M2 Metal film resistor, 1/4W Channel A input pulldown resistor. Can be anywhere from 1M to 2.2M.
RPD2 2M2 Metal film resistor, 1/4W Channel B input pulldown resistor. Can be anywhere from 1M to 2.2M.

GLADIATOR DUAL DRIVE 4
PARTS LIST, CONT.
PART VALUE TYPE NOTES
C1 22n Film capacitor, 7.2 x 2.5mm
C2 47pF MLCC capacitor, NP0/C0G
C3 47n Film capacitor, 7.2 x 2.5mm
C4 100n Film capacitor, 7.2 x 2.5mm
C5 220n Film capacitor, 7.2 x 2.5mm Alternative for C6. Recommended to use this instead.
C6 OMIT 0.22uF tantalum in original. Recommended to use C5 and omit C6.
C7 220n Film capacitor, 7.2 x 2.5mm
C8 220n Film capacitor, 7.2 x 2.5mm Alternative for C9. Recommended to use this instead.
C9 OMIT 0.22uF tantalum in original. Recommended to use C8 and omit C9.
C10 1uF Film capacitor, 7.2 x 3.5mm
C11 100uF Electrolytic capacitor, 6.3mm Reference voltage filter capacitor.
C12 10n Film capacitor, 7.2 x 2.5mm
C13 100pF MLCC capacitor, NP0/C0G
C14 10n Film capacitor, 7.2 x 2.5mm
C15 10n Film capacitor, 7.2 x 2.5mm
C16 15n Film capacitor, 7.2 x 2.5mm
C17 4n7 Film capacitor, 7.2 x 2.5mm
C18 100n Film capacitor, 7.2 x 2.5mm
C19 4.7uF Film capacitor, 7.2 x 7.2mm Electrolytic capacitor in original. See build notes.
C20 10n Film capacitor, 7.2 x 2.5mm
C21 10n Film capacitor, 7.2 x 2.5mm
C22 1uF Film capacitor, 7.2 x 3.5mm
C23 100uF Electrolytic capacitor, 6.3mm Reference voltage filter capacitor.
C24 100uF Electrolytic capacitor, 6.3mm Power supply filter capacitor.
C25 100uF Electrolytic capacitor, 6.3mm Power supply filter capacitor.
C26 100n MLCC capacitor, X7R Power supply filter capacitor.
D1 1N5817 Schottky diode, DO-41
D2 BAS33 Switching diode, DO-35
Original uses BA282 diodes. The BAS33 is the closest available diode
currently in production. See build notes.
D3 BAS33 Switching diode, DO-35
D4 BAS33 Switching diode, DO-35
D5 BAS33 Switching diode, DO-35
D6 BAS33 Switching diode, DO-35
D7 BAS33 Switching diode, DO-35
D8 BAS33 Switching diode, DO-35
D9 BAS33 Switching diode, DO-35
D10 1N914 Fast-switching diode, DO-35
D11 1N914 Fast-switching diode, DO-35

GLADIATOR DUAL DRIVE 5
PARTS LIST, CONT.
PART VALUE TYPE NOTES
IC1 RC4558P Operational amplifier, single, DIP8
IC1-S DIP-8 socket IC socket, DIP-8
IC2 RC4558P Operational amplifier, single, DIP8
IC2-S DIP-8 socket IC socket, DIP-8
CHAR.A 2-pos DIP DIP switch, 2-position
CHAR.B 2-pos DIP DIP switch, 2-position
DRIVE A 1MA 16mm right-angle PCB mount pot
DRIVE B 150kC 16mm right-angle PCB mount pot
TONE A 20kW 16mm right-angle PCB mount pot
TONE B 25kB 16mm right-angle PCB mount pot
VOL. A 100kA 16mm right-angle PCB mount pot Original uses 100kB, but audio taper provides better control.
VOL. B 100kA 16mm right-angle PCB mount pot Original uses 100kB, but audio taper provides better control.
EQ A SPDT cntr. off Toggle switch, SPDT on-off-on
EQ B SPDT cntr. off Toggle switch, SPDT on-off-on
LED A 5mm LED, 5mm, red diffused
LED B 5mm LED, 5mm, red diffused
IN 1/4" mono 1/4" phone jack, closed frame Switchcraft 111X or equivalent.
OUT 1/4" mono 1/4" phone jack, closed frame Switchcraft 111X or equivalent.
SEND NMJ6HC-S 1/4" phone jack, stereo, switched
RETURN NMJ6HC-S 1/4" phone jack, stereo, switched
DC 2.1mm DC jack, 2.1mm panel mount Mouser 163-4302-E or equivalent.
CH. A 3PDT Stomp switch, 3PDT
CH. B 3PDT Stomp switch, 3PDT
ENC 1590BBS Enclosure, die-cast aluminum

GLADIATOR DUAL DRIVE 6
BUILD NOTES
Clipping diodes
The Duellist uses BA282 diodes, which clip at a slightly higher threshold than standard silicon diodes
such as 1N914 (approximately 0.82V compared to 0.7V). These diodes are out of production and hard to
find in the old-stuck market.
Now, the closest option is the BAS33. These clip at around 0.8V, still significantly higher than the 1N914
and only slightly lower than the BA282. We’ve compared the curves on a Peak DCA75 and confirmed
that they closely match the BA282 across the current test range.
The only problem is that the BAS33 went end-of-life in early 2022. Availability is still high, but
eventually they’ll join the ranks of the others.
Omitting the send/return jacks
The loop between the two channels is a modification that is not in the original Duellist. This loop
automatically shorts together if nothing is plugged in, so it’s fully backwards-compatible if you don’t use
this feature. However, if you do want to omit it entirely, see the alternate wiring diagram on page 11.
Enclosure size
This project was designed for the Hammond 1590BBS enclosure, which has the same height as the
125B or 1590N1. If you don’t use the Hammond brand, be careful—not all 1590BBS enclosures are the
same. For example, Love My Switches sells two different types, and the CNC Pro version is correct while
the standard one is too short.
The 1590BB2 seems like a close equivalent, but it’s about 4mm shorter. It may be possible to fit this
circuit in a 1590BB2, but we have not tested it, so you’re on your own!
Another alternative is the 1590C (also available from Tayda and Love My Switches). It’s about 10mm
taller than necessary, but if that’s all you can find, it will definitely work.

SCHEMATIC
GLADIATOR DUAL DRIVE 7
CH.B OUT
CH.A IN
CH.B IN
CH.A OUT
CHANNEL A
FROM
INPUT
CHANNEL A
FROM
TO
OUTPUT
TO
CHANNEL B
TO
CHANNEL B
FROM
IN
JACK
OUT
IN
JACK OUT
VA VC VA VC
TO
SEND
RETURN
FROM
4k7
1N5817
+9V
100n
GND GND
GND
GND GND
100kA
20kW
1MA
2M2
GND
100R
47k
47k
GND
100uF
GND
100uF
VB
47k
47k
100uF
VC VDVA
100R
100uF
GND2 GND2
4k7
2M2
GND2
22n
RC4558P
RC4558P
VA
GND
47pF
1M
VB
1k
220n
VB
1uF
100kA
25kB
150kC
10n
RC4558P RC4558P
100pF
133k
1M
28k7
30k1
10n
10n
10k
100n 220k
5k6
1k
10n
9.53k
10n
1uF
GND2
VC
VD
VD
VD
VD
VD
4k7
15n
VDVD
4n7
GND2
47k
47n
4k7
VB
3k3
100n
20k
VB
OMIT 220n
VB
VB
220n OMIT
220R
10k
VB
1k
GND
4.7uF
R29
LED A
D1
A2
A3
A1
B2
B3 B1
C2
C3
C1
C26
VOLUME A
1
2
3
TONE A
1
2
3
DRIVE A
1
2
3
RPD1
C2
C3
C1
B2
B3 B1
A2
A3
A1
R24
R10
R11
C24 C11
R22
R23
C23
R25
C25
R30
LED B
RPD2
C1
6
5
7
IC1B 2
3
1
IC1A
84
C2
R1
R6
C5
D2
D3D4
C10
VOLUME B
1
2
3
TONE B
1
2
3
DRIVE B
1
2
3
C12
2
3
1
IC2A
6
5
7
IC2B
84
C13
R13
R12
R15
R14
C14
C15
R17
C18 R18
R19
D5 D6
D8D9
D10
D11
R20
C20
R21
C21
C22
R16
C16
EQ B
2
3 1
C17
D7
R2
C3
R3
R4
C4
R5
EQ A
2
3 1
C6 C7
C8 C9
R7
R8
R9
CHAR. A
BA282
1N914
CHAR. B
CHAR. B
CHAR. A
C19

GLADIATOR DUAL DRIVE 8
x: -1.725, y: +1.14
ø9/32”
x: -0.575, y: +1.14
ø9/32”
x: +0.575, y: +1.14
ø9/32”
x: +1.725, y: +1.14
ø9/32”
x: -1.725, y: -0.01
ø9/32”
x: +1.725, y: -0.01
ø9/32”
x: +1.60, y: -1.36
ø15/32”
x: -1.60, y: -1.36
ø15/32”
x: -0.825, y: -1.36
ø5/16”
x: +0.825, y: -1.36
ø5/16”
CENTER (0,0)
ø7/16”
1/2”
(12.7mm)
1/2”
(12.7mm)
0.80”
(20.3mm)
1/2”
(12.7mm)
1.60”
(40.6mm)
1.60”
(40.6mm)
ø3/8” ø3/8”
ø7/16”
0.80”
(20.3mm)
ø1/2”
RETURNOUTPUT INPUT
LOOP
SEND
LOOP
DC
VOLUME (B) DRIVE (B) DRIVE (A) VOLUME (A)
TONE (A)TONE (B) EQ (B) EQ (A)
CHANNEL B CHANNEL A
ø1/4” ø1/4”
x: -0.575, y: -0.01 x: +0.575, y: -0.01
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.
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

GLADIATOR DUAL DRIVE 9
ENCLOSURE LAYOUT
Enclosure is shown without jacks. See next page for jack layout and wiring.
1590BBS

GLADIATOR DUAL DRIVE 10
LOOP
SENDINPUT
LOOP
RETURN OUTPUT
DC
VAGNDOUT IN
VAGND
IN
CH.A
OUT
CH.A JACK SND RET +VGND JACK
OUTIN
GND
GND CH.B
OUT
CH.B
IN
VC
IN VC OUT
1590BBS
WIRING DIAGRAM
This is the default wiring diagram with the send/return loop. If you want to omit this loop, see the
modified wiring diagram on the next page.

GLADIATOR DUAL DRIVE 11
INPUT OUTPUT
DC
VAGNDOUT IN
VAGND
IN
CH.A
OUT
CH.A JACK SND RET +VGND JACK
OUTIN
GND
GND CH.B
OUT
CH.B
IN
VC
IN VC OUT
1590BBS
WIRING DIAGRAM (NO SEND/RETURN LOOP)
If you want to omit the send & return jacks, use the following wiring diagram. Note the jumper between
the SND and RET pads on the footswitch PCB.

GLADIATOR DUAL DRIVE 12
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 cannotbe 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
1.0.1 (2022-05-23)
Corrected resistors in parts list (R1-3 were listed twice).
1.0.0 (2022-05-13)
Initial release.