I have been using AR pre amps for years and have always found that the sovtek tubes are the first to go. ARC and many other manufactures use these tubes for their availablity. My favorite tube for the AR pamps are the German E188CCC.(US 7308) Most US and European Gold Pin tubes will give you more detail and less glare than the Russian and Chinese tubes.
I also use Mk 4 Black Diamond racing cones under my AR preamp and Mk 3 cones under the CD player, you can really fine tune the soundstage with these. Good Luck!
I also use Mk 4 Black Diamond racing cones under my AR preamp and Mk 3 cones under the CD player, you can really fine tune the soundstage with these. Good Luck!