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GEC KT88 single-getter vs. triple-getter tubes

I recently received a Unison Research Sinfonia integrated amplifier and tried various tubes with it. As output tubes, I tried three-getter GEC KT-88 tubes which are great but I felt that they are overblown and rather fat sounding and lack air and HF extension. The stock tubes (Sovtek KT-88 marked "Unison Research") and somewhat lighter and brighter in a good sense and I thought I would keep them as output tubes, until I inserted the earlier vintage single-getter Genalex KT-88 tubes, which have more high frequency extension and transparency and don't have such excessive "bloom" I was suffering from. Has anyone had similar experience with these two varieties of GEC tubes? I will also appreciate any tips about a reliable source of NOS/NIB GEC/Genalex KT-88 tubes.
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transl OP
156 posts
 
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.
transl OP
156 posts
 
Im my other amp (Hans Audio KT88), the reissue GL sound fantastic - clear, lively, dynamic and powerful.
transl OP
156 posts
 
Thank you, it's very interesting - about V-caps and everything. A year ago I replaced the stock 0.22uf caps in my Cary SLI-80 with V-caps and after a long, long burn-in (though their flavor was apparent at the outset) the amp opened up. Still, I believe thay are colored.
transl OP
156 posts
 
jtaysk: I don't have a tube tester. I ordered three-getter GEC tubes from HK as NOS two years ago and they appeared as such, but who can tell...

I've seen GEC tubes at Tejatubes, they also occasionally appear at Brent Jessee Recording, but the price is US$1500-1660 a quad.
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