tube upgrade for first sound


Has anyone been able to improve on the stock tubes in the First Sound preamps? I was thinking about trying the Russian 6H23. Any thoughts? thanks
84audio
Question....According to Emmanual, (and the owners manual) the break in period for an FS is 2 weeks. But alot of you fellow FS owners advise a month, before Tube and power cord experimentation. Any reason for this?

BTW - Yes the power cord was expensive. If it doesn't make a difference in my system....it will be up for sale. :-)

Thanks guys

paul
Give it a month so that you really get to know the sound of the broken in unit before you start experimenting.
Ok Fellas....What are the signs of a tube going bad? I am getting a distortion in the upper frequencies in the right channel of my new FS Pres. Deluxe MkII. It has happened within th past two days. Certain High pitches (piano music, flute/piccolo) Cause a slight fuzziness in the sound. It also sometimes sounds as though, a single note is seperating into 2 pitches.
I've ruled out the speakers - swapped them and it still does it. Ruled out the source - 2 different scources do the same thing. When I play my HT preamp (Lexicon MC8) on the same music, the distortion goes away. :-(
Besides a tube, going bad, I don't know what else it could be.
Do any of you fellow FS owners have any Ideas?
Any thoughts would be appreciated.

thanks

Paul
weird. never had this happen, but those tubes cant be bad. do you have a swap tube to try in its place - justy to see if it goes away?

Otherwise, you should call emmanuel
Artg has it right. Swap the two left channel tubes and the two right channel tubes. If the distortion moves to the left channel, you know it's one of the tubes. To determine whether it's the OA2 or 6922 tube, swap them with their partner one at a time.

If it's not a tube, call Emmanuel.