KT 170

They hit the xformers on any PL that uses 8 output tubes.

I contacted upscale audio a couple months ago about them: "We’re testing, buy kt-150’s". Screw that, you advertise as "future tube proof" so we’re gonna test. They are :)

EDIT: total cost for the 170's from viva tubes was 20 bucks less than 150's from upscale. Sure, it isn't much but thats 2 good grams of (legal) weed here.

"They hit the xformers on any PL that uses 8 output tubes."

stickmon42-
Is that what Upscale told you? Tubes contacting  the Xformer case seems like a concern. I have the HP=8 

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.