The Vertex Ultraphonix is an overdrive inspired by the sound of the legendary and ultra-rare Dumble Overdrive Special amps, used by legendary players such as Carlos Santana, Robin Ford and Kenny Wayne. It was built using four of those amps built between 1970 and 1990 as a reference.

The company recently updated it to MkII, whose design was improved based on feedback received from owners of the MkI. The most noticeable differences consist in the smaller footprint and new Level knob, which can add an extra 8dB of volume allowing to saturate the signal or more precisely match the input of the devices following in the chain (the original MkI level is set when you have that knob all the way anti-clockwise).

Here are the videos of the Vertex Ultraphonix MkII Special Overdrive, a pedal we added to our article about the Best D-Style Pedals.

Here’s MkI and the videos of it under the picture.


The Ultraphonix Overdrive is designed to re-create the overdrive produced by a Dumble™ Overdrive Special amplifier. Using a sample size of four generations of Overdrive Special amplifiers from 1970-1990 to voice and calibrate the pedal, the Ultraphonix is more than able to provide the D*style overdrive to any clean amp platform.


Voiced alongside four Dumble™ ODS amps ranging from 1970’s-1990’s
Quintessential D*style tone, note bloom, & harmonic overtones
100% Analog Circuitry
Mechanical “True Bypass” Switching
Designed & Assembled in California
9VDC center-negative power operation (adapter not included)