Originally Posted by dtiepelman
I hav both EL6A-hp/EL8A-hp bass tubes. I get a noticeable motor (putt-putt sound at any level whenever I turn up the bass boost. Is that a loose wiring or poor contact or poor grounding. Sometimes times lifting up the power wire quiets the motor sound. what gives?
Most often, induced noise is a result of a poor ground. Verify that your ground is adequate.