egg dating - Dating ge vacuum tubes

The white print has the HP logo and the Heerlen, Holland factory code is etched in the glass.

Both tubes test as new with phono grade noise levels. They are matched for current draw (45.0 & 47.6 m A) and Gm (4700 & 4900).

"North American Philips" is on the later generation boxes beginning in the 1970s.

date code 1960 - date in white writing is (1 14) 1961.

In Fender amps they will win every single time over the mass of 12ax7 tubes out there.