aion Silvanus User manual

SILVANUS AMP DRIVE 1
PROJECT NAME
SILVANUS
BASED ON
EFFECT TYPE
PROJECT SUMMARY
DOCUMENT VERSION
Xotic SL Drive
An overdrive inspired by the Marshall Super Lead Model 1959 and Super Bass amplifiers, famously used
by Jimmy Page and Jimi Hendrix.
Amp-like overdrive 1.0.1 (2023-11-27)
Actual size is 2.3” x 1.86” (main board) and 2.3” x 0.86” (bypass board).
BUILD DIFFICULTY
Easy

SILVANUS AMP DRIVE 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 Silvanus Amp Drive is based on the Xotic SL Drive, first released in the summer of 2013 and traced
by Aion FX in 2023.
The SL Drive was designed to emulate the tone of an overdriven Marshall Super Lead (hence SL) Model
1959 or Super Bass amplifier, calling to mind famous users of these amps such as Jimmy Page and
Jimi Hendrix. It’s an original circuit, though it has enough similarities to the RAT that they probably
referenced that circuit in the design process.
Internally, there are four DIP switch settings to change between the Super Lead and Super Bass modes
as well as a few other parameters. We’ve included a redrawn reference for these settings in the build
notes later on.
The Silvanus Amp Drive is a close adaptation of the SL Drive, including the DIP switches. The one
addition is that we added a clipping toggle switch, so you can engage the stock diodes or two other extra
settings. Other than that, it has the same controls as the originals, both inside and out.
USAGE
The Silvanus has the same control layout as a typical overdrive or distortion effect:
• Drive controls the amount of gain in the op-amp gain stage that precedes the diode clipping.
• Tone controls the treble response of the effect.
• Volume controls the overall output.
There are also four internal DIP switches and one external toggle:
• Hi-Mid Freq. 1 and Hi-Mid Freq. 2 set the midrange frequency response of the op-amp gain stage,
along with changing the overall amount of gain. Between the two switches, there are a total of four
different frequency & gain settings.
• Hi-Mid Cut changes the frequency of the tone control’s hi cut. The effect is more noticeable as the
tone control is turned down.
• +6dB Boost adds more gain in the post-clipping recovery stage. (Active when switch is OFF)
• Clipping (toggle switch) lets you choose between two combinations of silicon diodes (one in each
direction or two in each direction) or LEDs.
See build notes for more information on setting the DIP switches for certain amp models.

SILVANUS AMP 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 10k Metal film resistor, 1/4W
R2 470k Metal film resistor, 1/4W
R3 4k7 Metal film resistor, 1/4W
R4 3k3 Metal film resistor, 1/4W
R5 4k7 Metal film resistor, 1/4W
R6 1k5 Metal film resistor, 1/4W
R7 15k Metal film resistor, 1/4W
R8 10k Metal film resistor, 1/4W
R9 180k Metal film resistor, 1/4W
R10 82k Metal film resistor, 1/4W
R11 47k Metal film resistor, 1/4W
R12 390R Metal film resistor, 1/4W
R13 4k7 Metal film resistor, 1/4W
R14 470k Metal film resistor, 1/4W
R15 22k Metal film resistor, 1/4W
R16 22k Metal film resistor, 1/4W
R17 1k Metal film resistor, 1/4W
R18 10k Metal film resistor, 1/4W
R19 10k Metal film resistor, 1/4W
R20 100R Metal film resistor, 1/4W Power supply filter resistor.
RPD 2M2 Metal film resistor, 1/4W Input pulldown resistor. Can be as low as 1M.
LEDR 10k Metal film resistor, 1/4W LED current-limiting resistor. Adjust value to change LED brightness.
C1 15n Film capacitor, 7.2 x 2.5mm
C2 390pF MLCC capacitor, NP0/C0G
C3 150n Film capacitor, 7.2 x 2.5mm
C4 3n3 Film capacitor, 7.2 x 2.5mm
C5 47pF MLCC capacitor, NP0/C0G
C6 100n Film capacitor, 7.2 x 2.5mm
C7 1uF Film capacitor, 7.2 x 3.5mm
C8 10n Film capacitor, 7.2 x 2.5mm
C9 10n Film capacitor, 7.2 x 2.5mm

SILVANUS AMP DRIVE 4
PARTS LIST, CONT.
PART VALUE TYPE NOTES
C10 100n Film capacitor, 7.2 x 2.5mm
C11 1uF Film capacitor, 7.2 x 3.5mm Can omit and use 10uF for C12. See build notes.
C12 OMIT Electrolytic capacitor, 5mm Can use 10uF here and leave C11 empty. See build notes.
C13 47uF Electrolytic capacitor, 5mm Reference voltage filter capacitor.
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 5mm red LED, 5mm, red diffused Can also use 3mm.
D7 5mm red LED, 5mm, red diffused Can also use 3mm.
Q1 2N5457 JFET, N-channel, TO-92 Can substitute any general-purpose JFET.
IC1 JRC4558D Operational amplifier, dual, DIP8 See build notes for IC selection.
IC1-S DIP-8 socket IC socket, DIP-8
SW1 DIP switch, 2-pos. DIP switch, 2-position
SW2 DIP switch, 2-pos. DIP switch, 2-position
DRIVE 500kB 16mm right-angle PCB mount pot Linear taper.
TONE 50kC 16mm right-angle PCB mount pot Reverse audio (reverse log or antilog) taper.
VOLUME 100kA 16mm right-angle PCB mount pot Audio (log) taper.
CLIP SPDT on-off-on Toggle switch, SPDT center off
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.

SILVANUS AMP DRIVE 5
BUILD NOTES
Amp settings
The internal DIP switches allow the pedal to more closely emulate the Super Lead or Super Bass
amplifiers depending on the settings. Here are the positions Xotic recommends for each amp model:
Xotic also includes recommended drive and tone positions for each of these, but since these are very
much rig-dependent (not to mention the original amplifiers having drive and tone knobs of their own!)
they aren’t as crucial to capturing the tone.
IC selection
The IC is sanded down in the original SL Drive and it’s not known exactly what type they used. However,
based on our other traces, most Xotic circuits use the JRC4558D and at least one uses the LM833. We
recommend starting with the JRC4558D. From there, you can experiment with any standard dual type,
including the TL072, NE5532, or JRC4580.
Output capacitor
The SL Drive uses a 10uF capacitors (C12) as a signal coupler immediately after the JFET stage at the
output. We recommend keeping electrolytic capacitors out of the signal path wherever possible. This
PCB includes space for an alternate film capacitor (C11) in each of these positions.
Due to the low output impedance of Q1, 1uF is more than enough to pass all useful bass frequencies, so
it’s recommended to use a 1uF film capacitor in this position and omit C12. (1uF is the value used in the
RAT, which the SL Drive is loosely based on.) However, if you want to stick as closely as possible to the
original circuit, use 10uF for C12 and omit C11.
Super Lead Super Bass Super Lead+ Lead/Bass
ON
1 2
DIP
ON
1 2
DIP
+6dB BOOST
HI-MID CUT
HI-MID FREQ. 2 HI-MID FREQ. 1
ON
1 2
DIP
ON
1 2
DIP
+6dB BOOST
HI-MID CUT
HI-MID FREQ. 2 HI-MID FREQ. 1
ON
1 2
DIP
ON
1 2
DIP
+6dB BOOST
HI-MID CUT
HI-MID FREQ. 2 HI-MID FREQ. 1
ON
1 2
DIP
ON
1 2
DIP
+6dB BOOST
HI-MID CUT
HI-MID FREQ. 2 HI-MID FREQ. 1

SILVANUS AMP DRIVE 6
SCHEMATIC
GND
2M2
1N5817
100uF
500kB
50kC
GND
100kA
+9V
100n
VA
10k
15n
470k
10k
10k
47uF
100R
GND
VB
GND
VB
GND
VA
390pF
4k7
150n
3k3
VB
4k7 1k5
VBVB
15k
3n3
VB
1N914
1N914
1N914
1N914
VB
VB
10k
47pF
180k
82k
100n
47k
VB
1uF
390R
10n
4k7
GND
10n
VB
GND
100n
470k
VB
2N5457
VA
22k
GND
1uF 10uF
22k
GND
1k
IN
OUT
RPD
D1
C14
1
2
3
DRIVE
TONE
1
2
3
VOLUME
1
2
3
C15
R1
C1
R2
R18
R19
C13
R20
I
IC1 is sanded down in original
and the exact type is unknown.
Try JRC4558D or LM833N.
C1A
2
3
1IC1B
6
5
7
84
C2
R3
C3
R4 R5 R6
R7
C4
D2 D3
D4 D5
CLIP
2
3 1
D6
D7
R8
C5
R9
R10
C6
R11
C7
R12
C8
R13
C9
C10
R14
Q1
R15
C11 C12
R16
R17
SW2B
34
SW2A
1 2
34
SW1B
1 2
SW1A
GND

SILVANUS AMP DRIVE 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.
0 1 2
CM
0 1
INCH
x: -0.65, y: +1.71 x: 0.65, y: +1.71
ø9/32” ø9/32”
x: 0, y: +0.66
ø9/32”
x: 0, y: -1.20
ø15/32”
x: -0.775, y: -1.20
ø5/16”
CENTER (0,0)
ø3/8” ø1/2”
0.385”
0.625” 0.625”
ø3/8”
OUT DC IN
125B
VOLUME
CLIPTONE
DRIVE
FOOTSWITCHLED
x: +0.85, y: +0.66
ø1/4”

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

SILVANUS AMP DRIVE 9
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.

SILVANUS AMP DRIVE 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 (2023-11-27)
Added note about IC selection.
1.0.0 (2023-11-24)
Initial release.