Questions on KT150 tubes

I am now on my second set of KT150's in my Jadis amps. I noticed that the newer batch seem much more powerful than the originals. Quite odd.
That, plus apparently there are very few tube testers out there that can actually test these tubes accurately. They need 600 volts + to test and most ( including several Amplitrex models) cannot supply enough voltage to test them. I am still checking around to see which models of tube testers can actually accurately test them. 
Also, the new Jadis models have specific transformers in them that allow for the KT150 tubes...if yours is an older model, I think transformer damage is likely with the new tubes. Mk 2 models are required of the Jadis gear.

Thanks for the post, . 
I have a  good local tech geek who can advise me about employing the kt150's.
as you know jadis builds high quality trans, i do not run hot volume anyway. 
I plan to purchase the 150's,. if they run hot,,,for whatever reason,,i 'll go back to 88's. 
that will be  a  late 2020 project. 
i'm not worried about damage to the trans, as i say i listen on low gain,, 

@mozartfan   I would say that you will probably run into trouble with your Defy7. The KT150's are not going to bias properly in that circuit, would be my guess. If you damage the transformers with that misuse, I also suspect that Jadis will not warrant them. Like decooney stated above, best to call the dealer/distributor for Jadis first. Remember that the KT150's need at least 600+ volts at the plate. The new Jadis designs, called the MK2's are designed by Jadis to utilize the KT150's...and need a slight mod to utilize the more traditional tubes....BUT the older designs were NOT designed to utilize the KT150's.