Transformer saturation is one of two main loss factors with transformers, magnetic and ohmic losses. The doubling of the power in high power amps with low impedances highlights the problem of ohmic losses. There are two questions about reducing transformer losses: Does it correlate with better sound, and at which output power levels? And which design optimisation has to take places with which compromises to reach the intended goal. Think also about the sonic qualities of single ended amps, some tube amps too with extremely good bass, but no doubling of the power to lower impedances. The optimisation of audio quality in the major signal range is important - even with considerably compressed music the main energy range is at -10 dBU rel. level, which means at one tenth the peak power. With better material it's rather around -20dB and more. In a normal listening situation one is inclined to reduce the replay level. Generally 90dB medium level, except peaks is very loud. My speakers need less than one Watt average for this. Everything that improves sound quality from zero up to this power range has a lot to do with sound quality. Doubling the power into half of the impedance would be desirable, if there were no inherent sonic compromises. I know this flies in the face of orthodox engineering, but there is some empiric and well thought through truth to it.
Reducing ohmic losses leads to an extremely high current path for the capcitor / rectifier path, with considerable problems, exacerbated by "stable, high energy" designs with huge load capacitance.
Interestingly one of the better sounding Goldmund transistor amps as well as some Cello designs did search for an *optimal*, not maximal load capacitance, with very good results.
One of the reasons is reducing the stress factor inherent in increasing charge current peaks with increased capacitance. The same design compromise is involved with low loss transformers.
There is a way of thinking (shared by some famous names) that a "transformer only provides voltage & current and has no influence on the sound whatsoever". If one starts to experiment with different (brand) transformers, one finds the opposite is true.
This has - in empirical evidence - strongly to do with the magnetic circuit, and wire diameters (and rectifier and power supply design). This is a wide - empiric - research field of patient work, which very few people have done from both sides, the producing and listening side. Most any "normal" transformer is built following general design rules, strongly economical ones, which overlook some key factors, which are relevant "only" to audio. Optics are sometimes also optimised.
It's BTW a question too, how desirable a wide bandwidth is for a power transformer, which is an inherent property of the general winding technique of toroidals.
Reducing ohmic losses leads to an extremely high current path for the capcitor / rectifier path, with considerable problems, exacerbated by "stable, high energy" designs with huge load capacitance.
Interestingly one of the better sounding Goldmund transistor amps as well as some Cello designs did search for an *optimal*, not maximal load capacitance, with very good results.
One of the reasons is reducing the stress factor inherent in increasing charge current peaks with increased capacitance. The same design compromise is involved with low loss transformers.
There is a way of thinking (shared by some famous names) that a "transformer only provides voltage & current and has no influence on the sound whatsoever". If one starts to experiment with different (brand) transformers, one finds the opposite is true.
This has - in empirical evidence - strongly to do with the magnetic circuit, and wire diameters (and rectifier and power supply design). This is a wide - empiric - research field of patient work, which very few people have done from both sides, the producing and listening side. Most any "normal" transformer is built following general design rules, strongly economical ones, which overlook some key factors, which are relevant "only" to audio. Optics are sometimes also optimised.
It's BTW a question too, how desirable a wide bandwidth is for a power transformer, which is an inherent property of the general winding technique of toroidals.