AMX anecdote:
just hooked-up my amx 300B SET 10-watter, matched with my incredibly efficient Kenwood LS P9200 4way, 7 driver, 400watt-max speakers...
i noticed the stock 12AU7 tube had hints of microphonics, unfortunate... anyway, i go on with playing my usual test songs: ella fitz, gal costa, philip glass, etc... sweet and wet, but i had to pinpoint what set the sound apart...
so i put on my benchmark vinyl "Children of Sanchez" Chuck Mangione for the NAKAKAIYAK BA TEST. This album can make you cry listened through my Sennheiser HD598 through a tube preamp/headamp; but it fails to do so with my PushPull 6L6GC with speakers in my listening environment.
set with the 300B electro-harmonix on amx SET -- nakakiyak.