Made in Holland by Philips (parent company of Mullard, Amperex, etc). Same tube as sold/labeled by Amperex from the late '60s early '70s. Solid disk getter with the same plate structure as Mullard/Amperex ECC83s. I66 (delta) production codes. Great in guitar and audio applications. "Hi Mike, I'd like to order two more of those Dutch Phillips ECC83s. It's amazing what that tube does for both my Vox AC30 and brown Deluxe. David" "Hi Mike, I received all the tubes a couple of days ago