The Devil said:

People chasing THD measurements *do* have it wrong. Like
yourself, I don't know why this is the way it is (and like yourself,
BTW, I went to university to study electronic engineering - isn't
signing your name with the BSc appendage terribly snobbish behaviour
on such a forum? Although Arnii never did finish his, of course . . .
s******)

That's strange.......I never went to university, but I was told my
degree ( Ing., literally "engineer") was comparable to BSc abroad.

Another surprise: The Siemens drivers sound terrible in my amps (I
bought four pairs of them for £180 - ugh). Back to bog-standard (and
wonderfully cheap) Mullards - which are . . . ahem . . . glorious
(viva Zip!).

Ah! Those famous "diamond-bottomed" Siemens valves!
I told you that you've been had with those :-)

Next time, try before you pay. And while you're at it, do yourself a
favor and build a nice floating paraphase next.

--
Sander deWaal
"SOA of a KT88? Sufficient."