I saw this post from a member and I noticed the M50 is missing the Biphonic button.
https://boomboxery.com/forum/index.php/topic/26154-first-post-my-jvc-boxes/
Also,recognize that "B"?
https://boomboxery.com/forum/index.php/topic/26154-first-post-my-jvc-boxes/
Also,recognize that "B"?