Electric Blue Query

What does the knob to the right of the top C mounted on the wood in the corner do?

brightness control for the blue backlighting.

When I turn my backlight all the way up on my EB I hear a high pitched frequency noise that hums in my ears. Is this common?

When I turn my backlight all the way up on my EB I hear a high pitched frequency noise that hums in my ears. Is this common?

Yes. Search the archives for an explanation as this has been addressed many times before.

I figured it has been covered, I did a rough search but I didn’t find anything. Anyways I am sure I can find a few threads if I look hard enough.

Thanks.