Comparison of Vintage VS new Quad II amps

buy a david berning 30 watt amp or sigfried instead of the quad amps.

i had the original quad monos for 7 years driving the original quad esl.

i recently heard the reissued quad amp driving a quad 988 and the latest quad amp.

maybe it was tube selection, but i preferred the original amp.

KT66 are said to be much better than KT88-6550, a cult following almost, as good as the 300B, but harder to get and more expensive.
Good KT66 are Genelex made in England, either smoked glass or clear. There are new KT66 by Groove tubes, good but no comparison. Almost any good 6L6GC will work on the Quads, but original Quads are hard on tubes.
KT stands for Kinkless Tetrode, I am no expert but having a big coke bottle has something to do with less electron interference, there are a lot of cheap 6L6 branded KT66 due to its high price.
The original amps sound very good, detailed with beautifull highs.
I have not heard the new version so I cant compare.
That said I like my Quads with GE 5871 better...
Go figure!

To complicate this issue,I see that Quad also has the Quad II-40 with kt-88s.Jaybo-can you comment.I haven't heard the kt-66s in another unit.Can anyone comment on these two audio tubes,addressing availability,cost and sonics?

i owned the originals for years, and they were outstanding. the new classic ll's sound just as good....transparent as any set i've ever heard, but grunt to spare for classical and rock music........a real buy