Dear Raul, maybe you should read Löfgren's own papers in the original language they were written - in german. It help's understanding the matter.
Löfgren A is today more commonly named Baerwald.
Sorry, but Löfgren himself in his later comments ( in german again ...) to his own papers put together the characteristics of his calculation exactly as I described it earlier.
But maybe Löfgren was wrong about his own idea and you know certainly better.
Löfgren A spreads the two zeros further apart - Löfgren B puts them closer together.
Results in lower average but higher maximum distortions in Löfgren B and vice versa with Löfgren A/ Baerwald.
It is still about mono and not about microgroove and not about stereo.
Stevenson knew why he did went in other directions - he did so over 25 years later and with 8 years stereo available to the customer.
Nice to learn you do not hear any distortions - but that leaves a lot of possible explanations.
Cheers,
D.
