I haven't heard the 509 with Zingali, but have heard a pair of old 519 driving one of the bigger (model?) Zingalis. I liked the upper end extension & bass control. The "open-ness" & sense of space usually found in Zingali was there, too. Cabling used was Siltech silver something.
Difficult to compare to the Audion: I heard that driving a pair of Lowther-loaded speakers. I found the upper register slightly lacking -- but that could have been due to cable, speaker, etc...
I would *expect* the 300b to provide a more realistic mid-range on acoustic instruments & voice, while the Ear would possibly resolve difficult passages with more ease -- but that's conjecture.
Difficult to compare to the Audion: I heard that driving a pair of Lowther-loaded speakers. I found the upper register slightly lacking -- but that could have been due to cable, speaker, etc...
I would *expect* the 300b to provide a more realistic mid-range on acoustic instruments & voice, while the Ear would possibly resolve difficult passages with more ease -- but that's conjecture.