Diezel VH4

"Unlike traditional overdrive stomp boxes, the VH4 Pedal is a true preamp which delivers an authentic representation of its namesake – real Diezel tone – not emulated, not modeled, but sincerely reproduced. The entire signal architecture is faithful to the original: Bass, Mid, Treble and variable Deep and Presence controls allow you to tailor the uniquely Diezel Overdrive character. The command found in the Gain control gives a player everything they will ever need with lower gain settings producing the classic Diezel sparkle and chime to saturated mid-gain sounds, to scorching Diezel leads by cranking it all the way up.

As close to the original VH4 preamp, the VH4 pedal can be used as either an overdrive or as a standalone preamp to feed into your amps power section. What players take away by going direct into the power amp is all the dynamic, unfiltered Diezel tone by simply plugging into your amplifiers clean channel. Two outputs are provided with the first intended to connect to the front of a guitar amplifier and the second allows for a connection to a line-level power amp or power section of your amp via the Effects Return."
Original FSB thread and schematic available here.
This is a buffered effect.
Follow the layout's footswitch wiring.