aion PERELANDRA User manual

PERELANDRA BOOST / OVERDRIVE 1
PROJECT NAME
PERELANDRA
BASED ON
EFFECT TYPE
PROJECT SUMMARY
DOCUMENT VERSION
Xotic BB Preamp
A flexible drive pedal that can go from clean volume boost to smooth overdrive. Includes a 2-band tone
stack for treble & bass.
Boost / Overdrive 2.0.0 (2021-10-22)
BUILD DIFFICULTY
Easy
Actual size is 2.3” x 1.86” (main board) and 2.3” x 0.86” (bypass board).
This documentation is for the standard (non-deluxe) version of the project. Early PCBs of the
Deluxe version were labeled “Perelandra V2” rather than “Perelandra Deluxe”. Please make sure
your PCB matches the above image (four knobs and no toggles) before proceeding since the part
numbering is different. The Perelandra Deluxe is available as a separate project.
IMPORTANT NOTE

PERELANDRA BOOST / OVERDRIVE 2
TABLE OF CONTENTS
1Project Overview 7Drill Template
2Introduction & Usage 8Enclosure Layout
3-5 Parts List 9Wiring Diagram
6Build Notes 10 Licensing
7Schematic 10 Document Revisions
INTRODUCTION
The Perelandra Boost / Overdrive is a recreation of the Xotic BB Preamp, a flexible tone machine that
lets you go from a clean volume boost to a nice smooth overdrive with a 2-band EQ to shape the tone. It
was first released in 2005, a few years after the AC Booster and RC Booster, and the “BB” refers to the
Marshall Bluesbreaker amplifier.
Despite the name, the BB Preamp has nothing to do with the Bluesbreaker pedal. In fact, like the AC/RC
Booster, it’s very similar to the Ibanez Tube Screamer, but with an active Baxandall tone control added
before the output buffer so that the treble and bass can be independently boosted or cut.
In fact, if you look at the schematic for the BB Preamp, you can see that the original Tube Screamer tone
control stage is left intact, but with the tone knob is fixed at 5% rotation (i.e. almost fully to the dark side
of the control) by using a 1k and a 18k resistor. The main difference between the BB Preamp and the AC
or RC Booster is the presence of this Tube Screamer tone control stage to shape the tone going into the
Baxandall EQ.
Version 2 of the Perelandra is a full redesign based on traces of several versions of the BB Preamp in
2021. The PCB supports the standard BB Preamp (called the “version 1.5”), the AT (Andy Timmons)
model, and the Bass BB Preamp. Instructions have been provided for each variant. The default is version
1.5, the current production model.
The Perelandra Deluxe is hot-rodded version that incorporates modifications from the two Custom
Shop models of the BB Preamp, the “MB” (mid boost) and “Comp” versions. Since it’s a lot more complex,
we’ve split it off into a separate project. While the Deluxe version can emulate either the 1.5 or AT with
the right control settings, the bass version is not supported and can only be built on this PCB.
USAGE
The Perelandra has four controls:
• Gain controls the amount of gain from the op amp that is fed through the feedback clipping diodes.
• Treble is one half of the Baxandall tone control, allowing you to boost or cut high frequencies.
• Bass is the other half of the Baxandall tone control, allowing you to boost or cut low frequencies.
• Level sets the overall output of the effect.

PERELANDRA BOOST / 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 1k Metal film resistor, 1/4W
R2 470k Metal film resistor, 1/4W
R3 10k Metal film resistor, 1/4W
R4 10k Metal film resistor, 1/4W
R5 10k Metal film resistor, 1/4W Use 4k7 for bass version.
R6 4k7 Metal film resistor, 1/4W Use 10k for bass version.
R7 1k Metal film resistor, 1/4W
R8 10k Metal film resistor, 1/4W
R9 1k Metal film resistor, 1/4W
R10 18k Metal film resistor, 1/4W
R11 220R Metal film resistor, 1/4W Jumper for bass version.
R12 1k Metal film resistor, 1/4W
R13 1k Metal film resistor, 1/4W
R14 47k Metal film resistor, 1/4W Use 22k for bass version.
R15 10k Metal film resistor, 1/4W
R16 47k Metal film resistor, 1/4W
R17 4k7 Metal film resistor, 1/4W
R18 4k7 Metal film resistor, 1/4W
R19 33k Metal film resistor, 1/4W
R20 10k Metal film resistor, 1/4W
R21 470k Metal film resistor, 1/4W
R22 10k Metal film resistor, 1/4W
R23 470R Metal film resistor, 1/4W
R24 100k Metal film resistor, 1/4W
R25 10k Metal film resistor, 1/4W
R26 10k Metal film resistor, 1/4W
RPD 1M 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 1uF Film capacitor, 7.2 x 3.5mm 100n in bass version.
C3 47pF MLCC capacitor, NP0/C0G
C4 47n Film capacitor, 7.2 x 2.5mm Use 10uF for bass version. (positive leg to left pad)

PERELANDRA BOOST / OVERDRIVE 4
PARTS LIST, CONT.
PART VALUE TYPE NOTES
C5 220n Film capacitor, 7.2 x 2.5mm Omit (leave empty) for bass version.
C6 220n Film capacitor, 7.2 x 2.5mm Use 1uF for bass version.
C7 OMIT Use 1n for bass version. Omit (leave empty) for standard circuit.
C8 1uF Film capacitor, 7.2 x 3.5mm
C9 100n Film capacitor, 7.2 x 2.5mm Use 10uF for bass version. (positive leg to left pad)
C10 150pF MLCC capacitor, NP0/C0G
C11 33n Film capacitor, 7.2 x 2.5mm
C12 33n Film capacitor, 7.2 x 2.5mm
C13 4n7 Film capacitor, 7.2 x 2.5mm Use 10n for bass version.
C14 4n7 Film capacitor, 7.2 x 2.5mm Use 10n for bass version.
C15 1uF Film capacitor, 7.2 x 3.5mm Use 10uF for bass version. (positive leg to left pad)
C16 100n Film capacitor, 7.2 x 2.5mm
C17 1uF Film capacitor, 7.2 x 3.5mm Alternative to C18 for better-quality output capacitor.
C18 OMIT Use 10uF for original output capacitor. Recommended to use C17
instead except for bass version.
C19 47uF Electrolytic capacitor, 5mm Power supply filter capacitor.
C20 100uF Electrolytic capacitor, 6.3mm Reference voltage filter capacitor.
C21 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 Jumper for AT version.
D4 1N914 Fast-switching diode, DO-35 Jumper for AT version.
D5 1N914 Fast-switching diode, DO-35
Q1 2N5088 BJT transistor, NPN, TO-92 Substitute. Original uses 2SC1815.
Q2 2N5088 BJT transistor, NPN, TO-92 Substitute. Original uses 2SC1815.
IC1 JRC4558D Operational amplifier, DIP8
IC1-S DIP-8 socket IC socket, DIP-8
IC2 JRC4558D Operational amplifier, DIP8
IC2-S DIP-8 socket IC socket, DIP-8

PERELANDRA BOOST / OVERDRIVE 5
PARTS LIST, CONT.
PART VALUE TYPE NOTES
GAIN 1MB 16mm right-angle PCB mount pot
BASS 50kB 16mm right-angle PCB mount pot
TREBLE 50kB 16mm right-angle PCB mount pot
LEVEL 100kB dual 16mm right-angle PCB mount pot Linear taper, dual right-angle PCB mount.
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.
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.

PERELANDRA BOOST / OVERDRIVE 6
BUILD NOTES
“AT” (Andy Timmons) and “Version 1.5” models
In 2007, Xotic changed the BB Preamp to add an extra clipping diode in each direction (which they
described as reducing compression). Andy Timmons was an early endorser of the BB Preamp and
preferred the pre-2007 version. Because of this, Xotic re-released the pre-2007 version as the Andy
Timmons signature model (sometimes called the “BB-AT”).
While there have been a few very minor circuit changes to the BB Preamp along its production run, the
only thing distinguishing the AT from the non-AT version is the diodes. The AT version has one diode in
each direction while the later version has two in each direction.
The post-2007 version is now referred to as the “v1.5” by Xotic and is still in production. There is no
version 2, but presumably they didn’t feel the pre- and post-2007 versions were different enough to
warrant a whole number change in version as with the V2 AC/RC Boosters.
The default parts list provided above is for version 1.5, the current production model. To build the AT
version, just jumper one of the two diodes in each direction (i.e. D3 and D4).
Bass version
The Bass BB Preamp was released in 2006. It’s mostly the basic circuit, but it has a single capacitor
added and several part substitutions.
To build the bass version, change the following parts:
• C2: 1uF →100n
• C4: 47n →10uF (positive leg should go in left pad; will need to position it overlapping R5)
• C5: omit (leave empty)
• C6: 220n →1uF
• C7: 1n (normally left empty on standard version)
• C9: 10uF (positive leg should go in left pad; easiest to solder it to the bottom side of the PCB)
• C13: 4n7 →10n
• C14: 4n7 →10n
• C15: 1uF →10uF (positive leg should go in left pad; will need to position it overlapping R16)
• R5: 10k →4k7
• R6: 4k7 →10k
• R11: jumper
• R14: 47k → 22k

SCHEMATIC
PERELANDRA BOOST / OVERDRIVE 7
IN
OUT
GND
1M
1N5817
100uF
1MB
GND
50kB
50kB
+9V
100n
VA
10k
47uF
10k
GNDGND
VB
1k
22n
470k
2N5088
VA
10k
GND
1uF
10k
JRC4558D
47pF
10k
1k
220n
GND
4k7
33n 33n
4k7
33k10k
4n7 4n7
JRC4558D
VB
100n
470k
2N5088
10k
GND
VA
10uF
470R
100k
GND
VA
GND
JRC4558D
JRC4558D
VA
GND
150pF
47k
10k
VB
1k
220n
220R
GND
VB
VB
VB
VB
47n
4k7
VB
100kB
47k
10k
1uF
100kB
VB
1k
100n
1n
1k
18k
1uF
1uF
RPD
D1
C20
GAIN
1
2
3
TREBLE
1
2
3
BASS
1
2
3
C21
R25
C19
R26
R1
C1
R2
Q1
R3
C2
R4
IC1A
2
3
1
C3
D3 D2
R5
R7
C5
R17
C11 C12
R18
R19R20
C13 C14
6
5
7
IC1B
C16
R21
Q2
R22
C18
R23
R24
84
2
3
1
IC2A
6
5
7
IC2B
84
C10
R16
R8
R12
C6
R11
C4
R6
D4 D5
VOLUME B
1
2
3
R14
R15
C8
VOLUME A
1
2
3
R13
C9
C7
R9
R10
C15
C17
GND

PERELANDRA BOOST / OVERDRIVE 8
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, 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
LEVEL DRIVE
TREBLE BASS
FOOTSWITCHLED
x: -0.65, y: +1.71 x: 0.65, y: +1.71
ø9/32” ø9/32”
x: -0.65, y: +0.41
ø9/32”
x: 0.65, y: +0.41
ø9/32”
0 1 2
CM
0 1
INCH

PERELANDRA BOOST / OVERDRIVE 9
ENCLOSURE LAYOUT
Enclosure is shown without jacks. See next page for jack layout and wiring.
125B

PERELANDRA BOOST / OVERDRIVE 10
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.