Great topic Albert!! I bought my first all tube preamp with a phonoboard.The preamp is a Rogue 99 which is still a quite new piece from Rogue Audio. The first tubes in line in the phono stage were factory supplied Sovtek 12AX7LPS.This is a quiet tube and fairly decent.I was not happy.I was getting what is sometimes called "tube Rush" A low level hiss like noise.It was only audible during very quiet passages.I was told by several people this was normal and was "the nature of the beast"when it came to tube phono stages.I also was told this could not be corrected.Just a reminder,It really was very quiet and others could not hear the tube rush unless I pointed it out.Anyway,I was not happy!! I had just come from the Lehmann Black Cube outboard solid state phonostage.I was use to DEAD quiet.After consulting further with a "tube expert" I bought 2 Telefunken 12AX7's from Kevin Deal at Upscale audio.These 2 tubes have quieted my phono stage almost to the level the Black Cube was.I was told by 2 people who know the Rogue better than anyone that I was fighting a losing battle! WRONG! Besides silence,I now also have a much more revealing presentation of music,thanks to NOS telefunken 12AX7's!!
