Quoted from Kobaja:

Actually this is what I have been discussing with Pinnovators as well. We shared Ideas on how to implement a headphone jack that would have muting options and volume regulation, so a wireless BT transmitter can be hooked up to stream the pinball machines sound either in stead of or in parallel to the cabinet speakers.
For this reason: When you receive your correct set, please photograph the hell out of it and post all information pertaining to the pin headers and all that so Pinnovators can figure out how to do the magic.

Quoted from Kobaja:

Funny. Mark was the guy I talked to. To me it seems like Pinnovator's is having internal issues that need to be resolved before we take this discussion any further. :b

Quoted from Esoteric_rt:

Nice for USA buyers but export coin doors don't have that removable plate - so I guess we are shit out of luck?
STERN removed the headphone jack on the SPIKE board so you have to buy this accessory...and we cant use it!
Back to speaker wires from the cabinet sub it seems

Quoted from extendo:

Your saying that I can use the sub adaptor from my GBLE on my Bat66LE ?
The link doesn't show that in the compatibility tab.

Quoted from Schwaggs:

I've been using the cabinet speaker level connection to the sub. Are you saying your adapter will yield better sound than using this method?
Since your adapter taps into the backbox speakers, does it generate stereo sub signal or does your adapter mix it into a mono signal?