aion GLADIUS User manual

GLADIUS AMP OVERDRIVE 1
PROJECT NAME
GLADIUS
BASED ON
EFFECT TYPE
PROJECT SUMMARY
DOCUMENT VERSION
King Tone Soloist
A single-channel adaptation of side A of the popular Duellist dual pedal, based on a stripped-down
Ibanez Tube Screamer with hot-rodded features.
Overdrive 1.0.0 (2022-05-13)
BUILD DIFFICULTY
Easy
Actual size is 2.3” x 1.86” (main board) and 1.78” x 0.87” (bypass board).

GLADIUS AMP OVERDRIVE 2
TABLE OF CONTENTS
1Project Overview 7Drill Template
2Introduction & Usage 8Enclosure Layout
3-4 Parts List 9Wiring Diagram
5Build Notes 10 Licensing
6Schematic 10 Document Revisions
INTRODUCTION
The Gladius Dynamic Overdrive is based on the King Tone Soloist, traced by Aion FX in 2022. First
released in 2020, the Soloist is side “A” (String-Singer) of the Duellist dual pedal.
It’s no secret that it’s based on the Tube Screamer, but its modifications are significant enough that
depending on the control settings, it can either sound nothing like a TS or exactly like one.
However, the Soloist is not an exact copy of the circuit inside the Duellist. A “Body” potentiometer has
been added, and the “Fat” toggle mode has been swapped for the new “Edge” mode. The internal DIP
switch has been removed, so the “Warmth” and “Asymmetric” modes from the Duellist are not in this
circuit.
The Gladius unifies these two circuits, adding the internal DIP switch from the Duellist so that the
Warmth and Asymmetric modes are once again available. Otherwise, it’s a direct adaptation of the
Soloist standalone pedal.
USAGE
The Gladius has five external controls:
• Drive controls the amount of gain in the op-amp feedback diode clipping stage.
• Body controls the low-end response of the effect before the clipping.
• Tone is an active treble boost/cut after the clipping stage.
• Volume controls the overall output.
• Style (toggle switch) selects between Edge, Stock and Glass modes, which set the pre-clipping
treble response.
There are also two internal DIP switch options:
• Warmth adds a second treble-cut capacitor before the tone control, reducing the maximum amount
of treble available. Engaged when the DIP switch is “on”.
• Asymmetric adds another diode in series with the first set for asymmetric clipping. Engaged when
the DIP switch is “off”.

GLADIUS AMP OVERDRIVE 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 1k2 Metal film resistor, 1/4W
R5 3k3 Metal film resistor, 1/4W
R6 4k7 Metal film resistor, 1/4W
R7 OMIT Tapering resistor for Body pot. See build notes.
R8 1k Metal film resistor, 1/4W
R9 10k Metal film resistor, 1/4W
R10 220R Metal film resistor, 1/4W
R11 1k Metal film resistor, 1/4W
R12 10k Metal film resistor, 1/4W
R13 10k Metal film resistor, 1/4W
R14 100R Metal film resistor, 1/4W Power supply filter resistor.
RPD 2M2 Metal film resistor, 1/4W Input pulldown resistor.
LEDR 4k7 Metal film resistor, 1/4W LED current-limiting resistor. Adjust value to change LED brightness.
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
C6 220n Film capacitor, 7.2 x 2.5mm
C7 220n Film capacitor, 7.2 x 2.5mm
C8 1uF Film capacitor, 7.2 x 3.5mm
C9 100uF Electrolytic capacitor, 6.3mm Reference voltage filter capacitor.
C10 100uF Electrolytic capacitor, 6.3mm Power supply filter capacitor.
C11 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 available. See build notes.
D3 BAS33 Switching diode, DO-35
D4 BAS33 Switching diode, DO-35

GLADIUS AMP OVERDRIVE 4
PARTS LIST, CONT.
PART VALUE TYPE NOTES
IC1 RC4558P Operational amplifier, DIP8
IC1-S DIP-8 socket IC socket, DIP-8
CHAR. 2-pos. DIP DIP switch, 2-position
DRIVE 1MA 16mm right-angle PCB mount pot
BODY 150kC 16mm right-angle PCB mount pot Can also use 250kC with tapering resistor. See build notes.
TONE 20kW 16mm right-angle PCB mount pot
LEVEL 100kA 16mm right-angle PCB mount pot Original uses linear taper, but audio taper will provide better control.
STYLE SPDT cntr. off Toggle switch, SPDT on-off-on
LED 5mm LED, 5mm, red diffused
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.
FSW 3PDT Stomp switch, 3PDT
ENC 125B Enclosure, die-cast aluminum Can also use a Hammond 1590N1.

GLADIUS AMP OVERDRIVE 5
BUILD NOTES
Clipping diodes
The Heavyhand 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.
Body potentiometer
The Body pot is 150kC in the original, which is an odd value (though not impossible to find). R7 has been
added as a tapering resistor to approximate the 150kC value using a 250kC pot. If you use 250kC, then
use 390k for R7. The curve will be slightly different, but not drastic.

SCHEMATIC
GLADIUS AMP OVERDRIVE 6
1N914
GND
2M2
1N5817
100uF
1MA
150kC
GND
20kW
100kA
+9V
100n
VA
22n
10k
10k
100uF
100R
GND GND
VB
1M
RC4558P
RC4558P
VA
GND
VB
47pF
47k
47n
4k7
VB
1k2 3k3
VB
OMIT
VBVB
100n
4k7
1k
220n
10k
VB
220R
220n
1k
VB
VB
1uF
GND
220n
VB
IN
OUT
RPD
D1
C10
1
2
3
DRIVE
BODY
1
2
3
1
2
3
TONE
VOLUME
1
2
3
C11
C1
R12
R13
C9
R14
R1
2
3
1
IC1A
6
5
7
IC1B
84
C2
D2
D4
R2
C3
R3 R4 R5
STYLE
2
3 1
R7
C4
R6
R8
C5
R9
R10
C7
R11
C8
D3
CHAR.A
C6
CHAR.B
GND

GLADIUS AMP OVERDRIVE 7
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.
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: +0.775, y: +0.41
ø9/32”
x: 0, y: -1.20
ø15/32”
x: -0.775, y: -1.20
ø5/16”
CENTER (0,0)
125B
BODYTONE
DRIVE
x: 0, y: +1.06
ø1/4”
STYLE
VOLUME
FOOTSWITCHLED
ø3/8” ø1/2”
0.385”
0.625” 0.625”
ø3/8”
OUT DC IN
0 1 2
CM
0 1
INCH

GLADIUS AMP OVERDRIVE 8
ENCLOSURE LAYOUT
Enclosure is shown without jacks. See next page for jack layout and wiring.
125B

GLADIUS AMP OVERDRIVE 9
WIRING DIAGRAM
125B
IN +VGND N.C. N.C. OUT
PCB
IN
GND +V +V JACK GND JACK
OUTIN
GND GND PCB
OUT

GLADIUS AMP OVERDRIVE 10
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
1.0.0 (2022-05-13)
Initial release.