What is an “ultralinear” output transformer?
It’s a transformer with a tap at about halfway between the B+ connection and the plate connection to which you can attach the output tube’s screen grid. This connection provides some feedback to the screen grid as well as a bias voltage and has been found to act like a connection halfway between pure pentode modes and pure triode mode, with lower distortion than either. It’s almost a requirement for tube hifi ampliers. Bass amplifiers use it to get large amounts of clean power. It usually sounds too “sterile” or clean for guitar players’ tastes. Q: Can I convert an amplifier with an ultralinear connected OT to normal use? A: Yes. Just disconnect the ultralinear taps and make sure they don’t short to something, then connect the screen grids to a screen voltage supply. This is a common mod to UL connected amplifiers for guitar use. Q: Can I substitute two single ended transformers for a single plate-to-plate transformer? A: If you have two single ended transformers, these are running eff
