SETs get their capabilities from 3 things: Class A, triode, and reduced distortion at low power levels in the output transformer.
Push Pull amplifiers actually *increase* distortion as the power level falls to very low levels on account of the somewhat different behavior of their output transformers. Anytime distortion is increased, the masking effect of the human ear means that detail is obscured.
IOW its all about the transformer (its no problem to build a push-pull triode class A amplifier). But- take away the output transformer (get rid of it) and the argument against P-P vanishes.
At only 102db, unless you are just fine listening at relatively low levels, a 45 will not really produce enough power to be lifelike, although 45s otherwise sound quite impressive. It happens that in general, the smaller you make an SET, the better they sound (wider bandwidth). 10 years ago the 300b was king; 5 years ago the 2A3 had taken over but the 45 was already on its ascendancy...
Push Pull amplifiers actually *increase* distortion as the power level falls to very low levels on account of the somewhat different behavior of their output transformers. Anytime distortion is increased, the masking effect of the human ear means that detail is obscured.
IOW its all about the transformer (its no problem to build a push-pull triode class A amplifier). But- take away the output transformer (get rid of it) and the argument against P-P vanishes.
At only 102db, unless you are just fine listening at relatively low levels, a 45 will not really produce enough power to be lifelike, although 45s otherwise sound quite impressive. It happens that in general, the smaller you make an SET, the better they sound (wider bandwidth). 10 years ago the 300b was king; 5 years ago the 2A3 had taken over but the 45 was already on its ascendancy...