The Heliosphere Dual Distortion is based on the Stamps Amplification Drive-O-Matic, a very rare distortion pedal built by Robert Stamps of The Amp Shop in Los Angeles in the mid-1990s long before boutique pedals were mainstream. Despite the relative obscurity, the Drive-O-Matic was used by a few professional musicians such as Bonnie Raitt and Rick Vito. It was traced by Aion FX in 2023.
The Drive-O-Matic is clearly derived from the RAT Distortion, with a nearly identical circuit topology but several part value changes for a different voicing. The major feature addition is the channel-switching, in which a second footswitch engages an alternate drive knob and also switches out a filter that changes the tone somewhat.
Robert Stamps only made one other pedal under the Stamps Amplification name, a higher-gain variant called the Drive-O-Matic XL. This version removes the diode switch in favor of an added “Saturation” control (which may control the diodes directly), and presumably has some circuit tweaks to increase the gain based on the description. The Drive-O-Matic XL is extremely rare and has not yet been traced, but if we ever come across one then we’ll open it up and see what’s different about it.
The Heliosphere is an exact clone of the Drive-O-Matic based on our trace. Full details are available in the tracing journal.