I would contact Rogue and listen to them instead of advice from an audio forum.
But a number of us forum members have already talked to Rogue specifically about KT150. They’re a small company, so it’s nice to share information amongst owners rather than consuming more of their amp-building time for simply-answered calls and emails (though they are extremely pleasant to talk to in person).
KT150 is not recommended for any of their amps. I asked Rogue about using this tube in my Apollo monoblocks, since going from KT90 to KT120 was such a nice upgrade (one that Rogue themselves readily adopted) -- the answer was no; at a minimum the transformers would need to be redesigned for the KT150. Don’t do it. Would’ve cost me ~$1200 to re-tube, anyways!
