aion Blaze User manual

BLAZE DYNAMIC OVERDRIVE 1
PROJECT NAME
BLAZE
BASED ON
EFFECT TYPE
PROJECT SUMMARY
DOCUMENT VERSION
Amptweaker Tight Drive
An original drive pedal design from amp guru James Brown, the designer of the Peavey 5150 and JSX
amplifiers.
Overdrive with bass cut 1.0.0 (2023-11-24)
BUILD DIFFICULTY
Intermediate
Actual size is 2.3” x 2.42” (main board) and 1.78” x 0.86” (bypass board).

BLAZE DYNAMIC OVERDRIVE 2
TABLE OF CONTENTS
1Project Overview 8Drill Template
2Introduction & Usage 9Enclosure Layout
3-5 Parts List 10 Wiring Diagram
6Build Notes 11 Licensing
7Schematic 11 Document Revisions
INTRODUCTION
The Blaze Dynamic Overdrive is based on the Amptweaker Tight Drive, the very first pedal from amp
guru James Brown, who designed the Peavey 5150 amplifier. It was first released in 2010 and traced by
Aion FX in 2023.
The Tight Drive predated the Tight Metal and Tight Rock by a year. The topology is overall very similar
to these two later pedals, but simplified a bit. (The Tight Metal and Tight Rock circuits are available as a
hybrid project called the Ember Metal Distortion.)
In particular, it omits one clipping stage, the noise gate, some midrange shaping after the tone stack, and
a hi-cut at the output. The overall concept is similar, though: pre-drive bass cut, high-threshold zener
clipping, and a Big Muff-style tone stack.
The Blaze is a close adaptation of the Tight Drive based on our trace, only omitting the SideTrak effects
loop that is engaged when the pedal is activated.
USAGE
The Blaze has four knobs:
• Tight is a pre-gain bass cut that helps to eliminate flabbiness with quick riffing.
• Drive sets the gain of the second op-amp stage, which clips on its own and can also drive the third
op-amp stage into clipping.
• Tone pans between a high-pass and low-pass filter after the drive section, similar to the Big Muff
tone control.
• Volume is the overall output volume of the effect.

BLAZE DYNAMIC 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 470k Metal film resistor, 1/4W
R2 47k Metal film resistor, 1/4W
R3 15k Metal film resistor, 1/4W
R4 3k3 Metal film resistor, 1/4W
R5 22k Metal film resistor, 1/4W
R6 100k Metal film resistor, 1/4W
R7 15k Metal film resistor, 1/4W
R8 2k7 Metal film resistor, 1/4W
R9 10k Metal film resistor, 1/4W
R10 100k Metal film resistor, 1/4W
R11 10k Metal film resistor, 1/4W
R12 4k7 Metal film resistor, 1/4W
R13 1k5 Metal film resistor, 1/4W
R14 10k Metal film resistor, 1/4W
R15 47k Metal film resistor, 1/4W
R16 47k Metal film resistor, 1/4W
R17 1k Metal film resistor, 1/4W
R18 47k Metal film resistor, 1/4W
R19 22k Metal film resistor, 1/4W
R20 100k Metal film resistor, 1/4W
R21 150k Metal film resistor, 1/4W
R22 100k Metal film resistor, 1/4W
R23 150k Metal film resistor, 1/4W
R24 18k Metal film resistor, 1/4W
R25 47k Metal film resistor, 1/4W
R26 47R Metal film resistor, 1/4W Power supply filter resistor.
RPD 1M Metal film resistor, 1/4W Input pulldown resistor.
LEDR 10k Metal film resistor, 1/4W LED current-limiting resistor. Adjust value to change LED brightness.
C1 47pF MLCC capacitor, NP0/C0G
C2 100n Film capacitor, 7.2 x 2.5mm
C3 100pF MLCC capacitor, NP0/C0G
C4 22n Film capacitor, 7.2 x 2.5mm

BLAZE DYNAMIC OVERDRIVE 4
PARTS LIST, CONT.
PART VALUE TYPE NOTES
C5 33n Film capacitor, 7.2 x 2.5mm
C6 100n Film capacitor, 7.2 x 2.5mm
C7 47pF MLCC capacitor, NP0/C0G
C8 220n Film capacitor, 7.2 x 2.5mm
C9 220n Film capacitor, 7.2 x 2.5mm
C10 33n Film capacitor, 7.2 x 2.5mm
C11 100pF MLCC capacitor, NP0/C0G
C12 100n Film capacitor, 7.2 x 2.5mm
C13 22uF Electrolytic capacitor, 5mm
C14 100n Film capacitor, 7.2 x 2.5mm
C15 220n Film capacitor, 7.2 x 2.5mm
C16 33n Film capacitor, 7.2 x 2.5mm
C17 OMIT MLCC capacitor, NP0/C0G See build notes for possible modifications.
C18 100n Film capacitor, 7.2 x 2.5mm
C19 OMIT Film capacitor, 7.2 x 2.5mm See build notes for possible modifications.
C20 220n Film capacitor, 7.2 x 2.5mm
C21 22uF Electrolytic capacitor, 5mm Reference voltage filter capacitor.
C22 22uF Electrolytic capacitor, 5mm Reference voltage filter capacitor.
C23 22uF Electrolytic capacitor, 5mm Reference voltage filter capacitor.
C24 22uF Electrolytic capacitor, 5mm Reference voltage 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 1N914 Fast-switching diode, DO-35
Z1 1N4733A Zener diode, 5.1V, DO-41
Z2 1N4733A Zener diode, 5.1V, DO-41
IC1 TL072 Operational amplifier, dual, DIP8
IC1-S DIP-8 socket IC socket, DIP-8
IC2 TL072 Operational amplifier, dual, DIP8
IC2-S DIP-8 socket IC socket, DIP-8
TIGHT 50kC 16mm right-angle PCB mount pot Reverse audio (reverse log or antilog) taper.
DRIVE 500kA 16mm right-angle PCB mount pot Audio (log) taper.
TONE 10kA 16mm right-angle PCB mount pot Audio (log) taper.
VOLUME 10kB 16mm right-angle PCB mount pot Linear taper.
IN 1/4" mono 1/4" phone jack, mono
OUT 1/4" mono 1/4" phone jack, mono
DC 2.1mm DC jack, 2.1mm panel mount

BLAZE DYNAMIC OVERDRIVE 5
PARTS LIST, CONT.
PART VALUE TYPE NOTES
FSW 3PDT Stomp switch, 3PDT
ENC 125B Enclosure, die-cast aluminum Can also use a Hammond 1590N1.

BLAZE DYNAMIC OVERDRIVE 6
BUILD NOTES
Omitted capacitors
Two capacitors near the end of the circuit are unpopulated on the PCB. C17 is an op-amp feedback
capacitor to prevent oscillation, while C19 forms a low-pass filter to cut highs in conjunction with R17
As configured, the final op-amp stage gives a gain of 2. The presence of C17 indicates that the output
stage was likely originally designed to have higher gain, since the feedback capacitor is not needed if the
op-amp amplifies the signal only a small amount.
C19 indicates that there was originally some added tone shaping at the end, perhaps to correct for
an otherwise overly bright circuit. It’s possible the tone stack was tweaked in order to remove this
brightness so that the hi-cut was no longer needed.
In any event, since there was enough space on the PCB, we left these two capacitors in the circuit so you
could experiment if you want. Here are two suggestions to get you started:
• If you want to get more maximum volume out of the circuit, you can increase the value of R15 (e.g.
100k or 150k) and use 47pF for C17.
• To reduce brightness, turn the tone control all the way up and then select a value for C19 that
corresponds with the amount of treble you want to cut. For example, 22n will cut above 7.2kHz, or
47n will cut above 3.4kHz.

SCHEMATIC
BLAZE DYNAMIC OVERDRIVE 7
GND
1M
1N5817
100uF
GND
50kC
10kA
10kB
+9V
100n
VA
47pF
GND
100n
470k
22k
100k
22uF
VB
GND
GND
TL072P
TL072P
VA
GND
1N914
33n
3k3
GND
100n
22k
100k
100pF
10k
100n
4k7
22uF
GND
1k5
10k
100n
GND
220n
TL072P
TL072P
VA
GND
47k
47k
100n
GND
1k
220n
47k
GND
150k
22uF
GND
100k
22uF
GND
GND
150k
18k
47k
22uF
GND GND
VC
VD
47k 33n
GND
VB
100pF
22n
15k
GND
1N4733A 1N4733A
47pF
100k
500kA
220n 220n
15k
2k7
33n
10k
GND
OMIT
47R
OMIT
GND
VD
VD
VC
IN
OUT
RPD
D1
C25
TIGHT
1
2
3
TONE
1
2
3
VOLUME
1
2
3
C26
C1
C2
R1
R19
R20
C21
IC1A
2
3
1
2
3
1
IC2A
84
D2
C5
R4
C6
R5
R10
C11
R11
C12
R12
C13
R13
R14
C14
C15
6
5
7
IC2B
6
5
7
IC1B
84
R15
R16
C18
R17
C20
R18
R21
C22
R22
C23
R23
R24
R25
C24
R2 C16
C3
C4
R3
Z1 Z2
C7
R6
DRIVE
1
2
3
C8 C9
R7
R8
C10
R9
C17
R26
C19
GND

BLAZE DYNAMIC 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.
ø3/8” ø1/2”
0.385”
0.625” 0.625”
ø3/8”
125B
OUT
TONE DRIVE
VOLUME TIGHT
FOOTSWITCHLED
DC IN
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”
CENTER (0,0)
x: 0, y: -1.775
ø15/32”
x: -0.775, y: -1.775
ø5/16”
0 1 2
CM
0 1
INCH

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

BLAZE DYNAMIC OVERDRIVE 10
WIRING DIAGRAM
125B
IN +VGND NC NC OUT
PCB
IN
GND +V +V JACK GND JACK
OUTIN
GND GND PCB
OUT