When I re-read my initial post, I don't feel so bad. The C2300 has done something that no other preamp in my experience has ever done, and that is a wholesale change in sound quality over a period of 24 hours. All of things that I was complaining about disappeared in such a short period of time that I was and am astonished. And the good news is that I didn't need NOS tubes to change the sound of this preamp-I just needed break-in time. At some point I will still experiment with NOS tubes due to the very strong feelings that other posters have on the further positive impact it will have to the sonics of the 2300. If true, that would be really great.
As for the stock tubes, they are very quiet, the top end is sweet and extended, the bass is really good as is the midrange. The C2300 is a very quiet preamp. You can clearly hear the difference between the absolute noise floor of your LP playback system vice the noise floor of the actual LP you are playing. Before a song starts, you are hearing your absolute noise floor. Once the song starts, you are now hearing any noise associated with the actual recording. For instance, on LPs that are sourced from tape, you can hear the very gentle tape hiss as the song begins. On good quality LPs, this very low level hiss stands in sharp contrast to the almost sound of silence of the actual LP. Pretty cool.
