I had this Marshall code 50 with muffled sound. Even of i turned to max volume the sound is too low or weak.
its a hit or miss opportunity to make it work, sometimes the amp is working good then after minutes of playing the sound turns awful.
it happened after i updated to latest firmware, im suspecting its a bluetooth board error or a bad firmware update. Tried reseting, reupdating to no avail.
Does anyone tried to remove the bluetooth board?