Aion Electronics Titan Overdrive Manual

Titan Overdrive
Modified Voodoo Lab

Overview

Controls & Usage
• Drive controls the gain of the op-amp stage which increases the amount of signal clipping.
• Tone is a simple variable low-pass filter to control the amount of treble cut at the end, very similar to the
tone pot on a guitar.
• Volume controls the overall output level of the effect.
• HP/LP (High Peak / Low Peak) controls the frequency response of the tone control.
• Clipping allows you to select a second set of clipping diodes or bypass the diodes altogether.
Modifications & Experimentation
A charge pump has been included for built-in 18V operation. Use the jumpers on board to select either 9V or
18V mode. You can even put this on an external switch if you want, although you might need to use a bigger
enclosure or mount it to the side. You must use the jumpers to select either 9V or 18V mode or the effect
will not work!
The HP/LP switch controls a series resistor right before the output. It's often misunderstood to be a boost
switch of some sort. While it does affect the overall signal level, its primary purpose is actually to form an R-C
filter in series with C8, the tone capacitor, and so it affects the frequency of the tone that gets rolled off. The
tone control itself then affects how much of this treble-bleed is allowed to actually pass through to ground.
The original unit has 33k of total resistance in LP mode and 13.2k resistance in HP mode (33k and 22k in
parallel). I added a third position to this switch, a 10k resistor (RX1), that drops the total resistance down to
7.6k, which could be considered "Extra High Peak" mode. However, you could also set RX1 higher to get a
setting midway between High Peak and Low Peak—for example, a 56k resistor for around 21k total resistance.
TITAN OVERDRIVE - MODIFIED VOODOO LAB® OVERDRIVE
Overdrive
®
The Titan Overdrive is a modified version of the Voodoo
Lab Overdrive pedal. There have been a few commercial
®
pedals that were originally developed as modified VLODs
that have an enormous following.
The Voodoo Lab Overdrive was originally released in
®
1995 and was heavily inspired by the
circuit. Other pedalbuilders later added a tone control and
a different diode-clipping setup and tweaked two or three
other values to produce modified versions.
While these modified versions were originally designed for
9V operation, it's very common for people to run them at
18 volts, so this PCB has an optional charge pump to get
18V operation from a standard 9V supply.
This project includes the HP/LP switch from one notable
VLOD-inspired circuit, but adds a third option midway
between the two. It also includes a diode clipping switch
so you can experiment with other options.
Titan Project Link
Distortion+/250
1