dang. i wish i could just open the device up and solder something on there.   what about using a portable amp (powered by one AAA batt) that is supposedly "bass-heavy"? i am hoping that would equalize things into a bass heavy sound and lessen the sharp treble  

It's a Bluetooth receiver that  is stereo output,   http://i.imgur.com/pMBiRXe.png i connect a pair of earbuds, but i cut the wire to the right earbud (and toss the earbud in the garbage).. I'm guessing since the right earbud circuit is now broken, no power can be drawn by that circuit...

Regarding the photos, I wired to AA batteries to get longer battery life. About 20 hours instead of six hours under AAA batteries! I just keep the thing in my pocket. Plus eneloop rechargeables are awesome

I have this product. Its a bluetooth reciever   http://imgur.com/a/wUxiJ   http://i.imgur.com/Wv4bebk.png connected to my headphones, so I could have portable Bluetooth headphones. It is pretty loud, but only for the high treble. If the singer makes an S sound, it's this really...