It is supposed to be a neutral pass thru of a signal.
I don't buy for neutral, I buy for fun. I have to say the ARC is one of the most neutral bits of tube gear out there, which in my mind has made it a let down.
Lots of less expensive gear sounds as good to my ears in this generation.
Having said that.... Some vintage CJ or Luxman transformer volume controlled pre's can really add a lot of enjoyment and image to the experience.
Ayre, yeah, I like Ayre pre's a lot more too. :)
Best,
E