Conrad Johnson Premier 16 LS and NOS Tubes - Help

Has any owner of Conrad Johnson Premier 16LS used any NOS Tube in this preamp.What was your result with the sound quality.Do tubes like Seimens have a short tube life with Conrad Johnson products.Thank you for your Reply
I used Mullards. It sounded great.
I've tried Siemens Halske CCa's, they were very transparent and linear, had good bass and very clear highs. I'm currently using Amperex Holland 7308's, these, while maybe not as transparent, are more musical and natural sounding. Highly recommended! The Amperex Holland tubes, whether 6DJ8/6922/7308 seem to have an organic presentation that is very attractive.
I am using Siemen CCA very transparent and dynamic, I have heard the Telefunken CCA is very good too for midrange and high would like to try them myself.

I owned a CJ17LS and used a AudioPrism power cord and NOS Amperex tubes both of which made a huge improvement. I then upgraded to a CJ16 Series 2. The NOS tubes and power cord made very little improvement to the sound. My local CJ dealer heard the same thing as we did this one Sunday at his store. My recommendation would be to send your 16LS to CJ for the upgrade rather than spend $'s on NOS tubes and a good power cord.

- Ken
Kevin Deal at Upscale Audio is a great source for tubes; he sold me some tubes for my Audible Illusions L1 that has it sounding great!
I have the 16 Series-2 which came with the stock Sovetek tubes. When I changed over to Siemens, the change was not subtle. Much smoother highs, more pronounced bass but not mushier. I guess more organic sounding overall.