Jeff Irwin (Will Haven)

In a YouTube video at 1:19:23, Jeff Irwin of Will Haven states, "So that was pretty much my basic sound for the longest, it was an ADA Preamp," confirming his use of the A/DA MP-1 MIDI Programmable Tube Preamp.

In the YouTube video "#149: Jeff Irwin (Will Haven) | THE BOGCAST", at 1:19:22, Jeff Irwin explains, "So that was pretty much my basic sound for the longest it was the ADA Preamp and the Strategy 500 and the Strategy 500, Mesa just stopped making them all together and those things weighed like fucking 80 pounds like taking those things on tour was just a pain in the ass."

In the YouTube Guitar PlayThrough video originally uploaded on the Will Haven channel, Jeff Irwin can be seen using the Matrix GT1600FX on his effects rack. The description of the video also confirms this, stating: "Jeff plays: Amplification: ADA with Matrix gt1600fx."

Jeff Irwin of Will Haven confirms using the Marshall 1960A 4x12'' Cabinet in a YouTube podcast by Blue Dreamer Broadcast. At timestamp 16:58, he states, "Initially, my first setup when I bought my ESP, the first thing I bought was a 412 cab, which I still have today, actually Marshall. 1960 cab. And then I had bought a 1960A Marshall head, 100 watt head. And then I went and jammed with Chris Robyn from FAR. When I first got it, just to try it out, and I couldn't hear myself."