Amperex tubes manufactured in the Heerlen plant were not all the same. The PQ series were different than the Bugle Boys as were the rare pinched waist tubes.
From Brent Jessee:
Holland tubes marked with the Bugle Boy logo were 6DJ8 type, no gold pins. Later 6DJ8 production tubes with white or orange labels were the same tooling as the Bugle Boy.
Bugle Boys from Holland were the same tube as the Philips Mini Watt.
An Amperex PQ 6DJ8, 6922, 7308 were the same tube measured to the same tolerances as a Philips SQ.
From Brent Jessee:
E88CC / 6922 Amperex Holland made white PQ type, white label gold pins.
These have been rated by audiophiles as as good if not better than the famous Amperex, and rivalling the famed Amperex 7308 white label tubes! Most are Philips SQ or Amperex PQ labels. Some are labelled for Mullard, Philips, Dario, RTC, Valvo or other brands, but all have the Philips Heerlen Holland factory code.
Holland tubes marked with the Bugle Boy logo were 6DJ8 type, no gold pins. Later 6DJ8 production tubes with white or orange labels were the same tooling as the Bugle Boy.
Bugle Boys from Holland were the same tube as the Philips Mini Watt.
An Amperex PQ 6DJ8, 6922, 7308 were the same tube measured to the same tolerances as a Philips SQ.