Interstage transformers are very popular in my house. Especially since Hammond introduced the 124 series. I'm just finishing a PP 6B4G amp that uses a 124E driven by a 7044 in SE parafeed. Lots'a old paper in oil coupling caps. I know everyone says that good ITs have to be hideously expensive, not me. But hey, I'm just an experimenter, not an "audiophile." I do like music.The 6B4G SE amp currently in my system is 6n1p (both sections parallel) driving a 124B IT (parafeed). Talk about el cheapo, the output transformer on that beast is a Rat Shack 70v line transformer!
TC