Line Magnetic LM215 CD player - internal adjustment?

I'm wondering if anybody knows what the adjustment pot is for that sits inside at the rear - close to the COAX and Optical outputs? I thought it may have been a volume adjustment, but it doesn't appear to affect that - or a channel balance. It has a 360º range. 
I'm running into an MHDT Atlantis via Coax and then into a Shindo Partager pre.  
I can't find anything online or in the manual.

Suggest maybe contacting Jonathan Halpern at Tone Imports (US distributor for LM) and if he doesn't know offhand can probably find out for you, I have found him to answer emails timely.