Merci! ....Well like you i had the C50 and since i upgraded to the C1000/C1000T ....its been "Organic Bliss x10"for me if you get the C500 or C1000 i dont think you would ever regret it
Today I received my matched balanced sets of Gold Lion Tubes .....I learned how to install them correctly in my C1000T ....i must say i had no clue what to expect in sound change,but I am happy to report that there IS a positive change in sound quality compared to the stock tubes! ......i would imagine the sound will improve once the Gold Lions are broken in.
I agree with Mike. The tesla e83cc are THE best 12ax7 tube I have heard. I used them in my c2300 and now in my C500. I have a back up quad, they are that good.