aion XIPHOS User manual

XIPHOS AMP OVERDRIVE 1
PROJECT NAME
XIPHOS
BASED ON
EFFECT TYPE
PROJECT SUMMARY
DOCUMENT VERSION
King Tone Heavyhand
A single-channel adaptation of side B of the popular Duellist dual pedal, based on a Marshall
Bluesbreaker with hot-rodded features.
Amp-like overdrive 1.0.1 (2022-05-18)
BUILD DIFFICULTY
Easy
Actual size is 2.3” x 1.86” (main board) and 1.78” x 0.87” (bypass board).

XIPHOS 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 Xiphos Amp Overdrive is based on the King Tone Heavyhand, traced by Aion FX in 2022. First
released in 2021, the Heavyhand (sometimes rendered as Heavy Hand) is side B of the Duellist dual
pedal, derived from the Marshall Bluesbreaker overdrive circuit but with several added modifications
and switch options.
However, it’s not an exact copy of what’s inside the Duellist. While it does share the core circuit in
common, the Duellist is capable of some modified tones that the Heavyhand can’t match, and vice versa.
Notably, the Heavyhand adds an additional Body potentiometer, a new diode selector switch, and swaps
out the “Fat” toggle mode for a new “Edge” mode.
The Xiphos unifies these two circuits, porting the features from the Duellist that were not on the
original Heavyhand. An additional diode has been added in one direction on a DIP switch, making the
stock clipping mode asymmetric when active. It also has an option for diode-to-ground hard clipping,
also via an internal DIP switch. Note that since the hard-clipping mode has a low clipping threshold, the
external diode selector switch won’t have as much audible effect when the hard clipping is enabled.
USAGE
The Xiphos has six external controls:
• Drive controls the amount of gain going into the op-amp feedback diode clipping stage.
• Body controls the low-end response of the effect before the clipping.
• Tone controls the treble response after the clipping via a passive filter.
• Level controls the overall output.
• Clipping (toggle switch) selects between two different diode combinations (Stock and Comp) or a
diode-lift mode (Open) in the center.
• 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:
• Hard Clipping adds a second set of diodes for hard-clipping mode, similar to the King of Tone.
Engaged when the DIP switch is “on”.
• Asymmetric adds another diode in series with the first set for asymmetric clipping in stock mode. It
has no effect in the Comp or Open modes. Engaged when the DIP switch is “off”.

XIPHOS 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 133k Metal film resistor, 1/4W
R3 OMIT Use 360k if using a 250kB drive pot. See build notes.
R4 OMIT Use 22k if using a 250kB drive pot. See build notes.
R5 4k7 Metal film resistor, 1/4W
R6 28k7 Metal film resistor, 1/4W
R7 30k1 Metal film resistor, 1/4W
R8 10k Metal film resistor, 1/4W
R9 220k Metal film resistor, 1/4W
R10 5k6 Metal film resistor, 1/4W
R11 1k Metal film resistor, 1/4W
R12 9k53 Metal film resistor, 1/4W
R13 47k Metal film resistor, 1/4W
R14 47k Metal film resistor, 1/4W
R15 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 10n Film capacitor, 7.2 x 2.5mm
C2 100pF MLCC capacitor, NP0/C0G
C3 10n Film capacitor, 7.2 x 2.5mm
C4 4n7 Film capacitor, 7.2 x 2.5mm
C5 10n Film capacitor, 7.2 x 2.5mm
C6 10n Film capacitor, 7.2 x 2.5mm
C7 47n Film capacitor, 7.2 x 2.5mm
C8 100n Film capacitor, 7.2 x 2.5mm
C9 1uF Film capacitor, 7.2 x 3.5mm Not in original unit, but recommended to use instead of C10.
C10 OMIT 4.7uF electrolytic in original. See build notes.
C11 10n Film capacitor, 7.2 x 2.5mm
C12 10n Film capacitor, 7.2 x 2.5mm
C13 1uF Film capacitor, 7.2 x 3.5mm
C14 100uF Electrolytic capacitor, 6.3mm Reference voltage filter capacitor.
C15 100uF Electrolytic capacitor, 6.3mm Power supply filter capacitor.

XIPHOS AMP OVERDRIVE 4
PARTS LIST, CONT.
PART VALUE TYPE NOTES
C16 100n MLCC capacitor, X7R Power supply filter capacitor.
D1 1N5817 Schottky diode, DO-41
Original uses BA282 diodes. The BAS33 is the closest available diode
currently available. See build notes.
D2 BAS33 Switching diode, DO-35
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 1N914 Fast-switching diode, DO-35
D8 1N914 Fast-switching diode, DO-35
IC1 RC4558P Operational amplifier, DIP8
IC1-S DIP-8 socket IC socket, DIP-8
CHAR. 2-pos. DIP DIP switch, 2-position
DRIVE 150kC 16mm right-angle PCB mount pot Can also use 250kB with tapering resistors. See build notes.
BODY 500kC 16mm right-angle PCB mount pot
TONE 25kB 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.
CLIP SPDT cntr. off Toggle switch, SPDT on-off-on
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.

XIPHOS 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.
Drive potentiometer
The Drive pot is 150kC in the original, which is an odd value (though not impossible to find). R3 and R4
have been added as tapering resistors to approximate the value and curve of a 150kC using a 250kB pot.
If you use 250kB, then use 360k for R3 and 22k for R4. This method is far from exact, though, so try to
use a 150kC if you can find one.
C9/C10 capacitor
C9 has been added as a film cap alternative to the 4.7uF electrolytic used in the original. Film caps
are better quality for signal coupling, and 4.7uF is much higher than necessary in this position, so it’s
recommended to use C9 and omit C10.
Knobs
Since the two lower pots are very close to the lower toggle switch, it’s recommended to use 1/2” knobs
for these two. The upper two knobs can be 3/4”. This is the cosmetic look we used for the Penumbra
Bass Fuzz, which uses the same drill template.

SCHEMATIC
XIPHOS AMP OVERDRIVE 6
GND
2M2
1N5817
100uF
150kC
500kC
GND
100kA
25kB
+9V
100n
VA
10n
47k
47k
100R
100uF
GND GND
VB
1M
VB
RC4558P
RC4558P
GND
VA
100pF
133k
OMIT OMIT
10n
4k7
4n7
VB
28k7 30k1
10n
10n 47n
VB
VB
10k
100n
VB
220k
5k6
1k
1uF OMIT
VB
10n
VB
9k53
10n
1uF
VB
GND
IN
OUT
RPD
D1
C15
1
2
3
DRIVE
BODY
1
2
3
LEVEL
1
2
3
TONE
1
2
3
C16
C1
R13
R14
R15
C14
R1
2
3
1
IC1A
84
6
5
7
IC1B
C2
R2
R3 R4
C3
R5
2
3 1
STYLE
C4
R6 R7
C5
C6 C7 R8
C8
R9
2
3 1
CLIPPING
D2 D3 D4
R10
D5 D
BA282
1N914
6
CHAR.A
R11
C9 C10
D7
D8
CHAR.B
C11
R12
C12
C13
GND

XIPHOS 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, 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
BODYTONE
DRIVECLIPPING
x: 0, y: +1.06
ø1/4”
STYLE
LEVEL
FOOTSWITCHLED
ø3/8” ø1/2”
0.385”
0.625” 0.625”
ø3/8”
OUT DC IN
0 1 2
CM
0 1
INCH

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

XIPHOS 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

XIPHOS 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
1.0.1 (2022-05-18)
Corrected description of asymmetric diode switch function.
1.0.0 (2022-05-13)
Initial release.