I'm upgrading to the Ultra Phonix MKII. No power supply.

Here's the description from Vertex:

The Ultraphonix Overdrive is designed to recreate the overdrive produced by a Dumble Overdrive Special amplifier. Four Overdrive Specials were used in the voicing and calibration of the Ultraphonix, each amp ranging in origin from the years 1970-1990. Being modeled after four different generations, the Ultraphonix accurately captures the character of the legendary Dumble amplifier, regardless of the minute and more apparent differences in the amp from year to year. The Ultraphonix is more than able to provide the D*style overdrive in front of any clean amp platform. Engage the Ultraphonix in tandem with another overdrive pedal or in front of a broken-up amp to really cut through a mix with a huge lead tone or thundering rhythm tone.