aion Arcturus Manual - Page 2
Browse online or download pdf Manual for Music Pedal aion Arcturus. aion Arcturus 11 pages. Natural overdrive
Print PageTABLE OF CONTENTS
1 Project Overview
2 Introduction & Usage
INTRODUCTION
The Arcturus Natural Overdrive is based on the Nobels ODR-S Overdrive Special, first released in 1993
as a sibling of their more famous ODR-1.
Compared to the ODR-1, the ODR-S has a nearly identical drive section, except that the hard-clipping
diodes are germanium instead of silicon. The main difference is in the tone stack. The ODR-1's Spectrum
control has been replaced by a full 3-band EQ. The midrange control uses the same transistor gyrator
concept as the Spectrum control, though it's tuned very differently, while the bass and treble controls
are a standard Baxandall arrangement.
The Arcturus is a direct adaptation of the ODR-S, but with the JFET switching removed in favor of true
bypass. We have also added an optional correction for what has been seen as an error in the original
design related to the input bias of the second op-amp stage. This is described in detail in the build notes
if you're curious.
In 2023, Kai Tachibana, the original designer of the ODR-1 and ODR-S, released a pedal called the
ODR-CS Custom Special
anniversary. The ODR-CS is a re-engineered version of the ODR-S that uses better quality components
than the original Nobels unit as well as true bypass switching. It also has a few editorial changes,
primarily in the three bands of the tone stack.
The Nordland ODR-CS has not been traced as of this writing, so we are not sure what exact schematic
changes were made. But Nordland makes a fantastic product, so we strongly recommend buying one
from them if you are interested!
USAGE
The Arcturus has five knobs:
• Gain controls the amount of gain in the first op-amp stage.
• Low boosts or cuts low frequencies centered around 100-200 Hz.
• Mid boosts frequencies centered at 800-900 Hz.
• High boosts or cuts high frequencies centered around 3-4kHz.
• Level is the overall output level.
ARCTURUS NATURAL OVERDRIVE
under his company Nordland Electronics in honor of the original pedal's 30th
11 Licensing
2