I have a 2015 Bfr L3. when the battery starts to go, it makes the preamp shoot up in volume, when engaged.
Mine has always been just a few db more when clicked on, more of a feeling thing than volume boost.
but once the battery starts to die, it will push the volume above clipping level. but once its changed, its back to normal. Im going through a battery once a month, about 4-5 hours of sessions daily.
trying to figure out if this is a preamp problem to get fixed, or if anyone else has experienced this.