I compared new GL KT-88 with 1977/78 vintage British-made GEC KT-88. They are not the same. Here are my comments:
I played the new Gold Lions for approx. 20 hours (perhaps its not sufficient). My first impression was that they sounded very similar, but it is not so. They are similar in terms of power - they have a very dynamic and powerful sound, with overblown midrange and truncated highs. The original GEC tubes have more air and midrange delicacy - yes, it's delicacy which the new GL tubes lack. Besides, the new tubes have a characteristic Sovtek-style metallic sheen in the midrange, which is not present in the original tubes.
The amp is Cary SLI-80.
I played the new Gold Lions for approx. 20 hours (perhaps its not sufficient). My first impression was that they sounded very similar, but it is not so. They are similar in terms of power - they have a very dynamic and powerful sound, with overblown midrange and truncated highs. The original GEC tubes have more air and midrange delicacy - yes, it's delicacy which the new GL tubes lack. Besides, the new tubes have a characteristic Sovtek-style metallic sheen in the midrange, which is not present in the original tubes.
The amp is Cary SLI-80.