@k4rstar named output transformer brands of which many I have not been particularly fond of, although some people do like them. These were Lundahl, Hammond, Cinemag, Hashimoto, Tamura, Tango. Of these, I liked one Tango, but this was an expensive high-end model with amorphous cores, and this was before they went bankrupt / kaput and resurrected. Hammond is run of the mill. Cinemag makes better small signal transformers than output transformers. Lundahl are somewhat overpriced and never found an OPT that I really loved from them - besides their expensive chokes don't do any better than cheap chokes from China or anything from MCI. The Tamura and Hashimoto I found unimpressive, particularly the one of latter which was in a Leben, but that could have been the Leben amp. The output transformers I liked have been from ElectraPrint ($$), Monolith ($$$), Audio Note ($$$$), the vintage Fischer PP amp kit, and a Chinese "Advanced 300B" deal ($$) which appears to be a successful reverse engineer of a vintage American transformer. I'm not sure OTL is much better because it's dependent upon the coupling capacitor, and we all know how stupid esoteric that can go too, even moreso than output transformers. The downsides with OTL are varying levels of veil and murkiness in the lows. Also OTL has a big technical downside: high source impedance.