KT 170

That's from the Facebook PL group, think someone measured and verified with upscale but it wasn't me. I have no way of actually verifying if it's true or not but it would be a major concern. 

All I can say for certain is that they work extremely well in an evo 300 power amp. 

I have less than five hours on a quad of them. I’m thrilled. It’s like having a new system. More lower mids, bass, live music feel. Was using KT-88’s. Speakers are not efficient ones. Got an email from my Amp maker saying he’s now offing them, so no worries in trying. 

Cuss words of joy. To me the lower volumes is where the fuller sound comes out. Loud is loud. By by KT 88’s I have a new love. My wife gave me a perfunctory agreement but that’s suspect. But she stayed for a while asking to hear some of her favourites. 

"It’s like having a new system. More lower mids, bass, live music feel. Was using KT-88’s."

wsrrsw-It's always fun to have that experience with a new addition.
I'm disappointed I can't try them in my amp PL HP. I will contact them directly to get confirmation on what stickmon42 indicated.

Full stop... Have to send back AMP (Roders KWM-88 Integrated Amplifier) to get some changes made inside to use KT170's so as not to damage amp. Went back to 88’s and will dig out shipping box ASAP.