2 thoughts on “Philips 12au7 Welded Plates 1956

  1. There is a believe that the earlier the production of the tube, the better it sounds. Let’s see, I came across Philips from 1956 with D-getter (WHAT?!) and date code DeltaL K6A. It has welded plates, which are very, very unusual. This tube looks and sound unique very soft sound, very early roll off in high frequencies (just think about it, who needed extension to 20KHz when speakers stopped at 15Khz). Not my favorite tube. A love the later productions of Philips, but this one is very slow, very soft and not very transparent.

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