“Theory C: it’s a scoop knob... they built James’ parametric EQ into the amp”: Metallica spark a Mesa/Boogie mystery as unidentified amp spotted in 50th Anniversary message to ESP Guitars. Could this be a James Hetfield signature?

A still from a YouTube video featuring Kirk Hammett in a white T-shirt with "Let's Go" written on the front. Guitar amps are in the backgound.

Metallica’s James Hetfield and Kirk Hammett took to YouTube to wish ESP Guitars a very happy 50th Anniversary, the long-time endorsees checking in from their rehearsal room HQ, signature guitars in hand. But in the process they might just have something very intriguing indeed.

There’s an Easter egg in this video, and it looks like this could be a signature tube amp for Hetfield from Mesa/Boogie. Once you can see it you can’t unsee it. Behind Hammett, there’s a guitar amp head, sitting on a 4x12 guitar cabinet with a Metallica logo stencilled in white on the black grille cloth.