DSM / Humboldt Electronics on Instagram: "This is one of the Dumble amplifiers we had rare access to during our search to understand what truly makes them special. This exact amp was a key reference in the development of the Dumblifier “Edge of break-up” sound. Filmed at @guitar_shop_hoochies , Tokyo 🇯🇵 — one of the most respected boutique guitar shops in the world. This amplifier is also known as one of the “secret” Dumble amps seen live with John Mayer. This footage is part of a mini documen