As an absolute newbie to the world of tubes I am looking at an
S.G.JoLida Integrated amp/pre-amp advertised in Audio Advisor. It is a 
Model #SJ502A, rated at 85 WPC and driven by 2 matched pairs of Russian
6550s with two 6DJ8s and two 12AT7s. The specs look good and the listed
price is $999 (US). They have two lesser models running from $699 to 
$850 at 50 WPC and 65 WPC. However neither of these models utilize the 
Russian 6550s.
        I have large full range speakers that are very sensitive, a
large listening area absent any side walls of note with a cathedral
ceiling. I listen to classical, new age, female vocal, chamber music,
string quartets and soft rock mostly. But would also like to be able to
fire up my 60s hard rock every once in a while.
        1. How long should you expect to get out of a set of tubes?
        2. How long should a tube unit be allowed to "warm up" 
           before playing?
        3. Do the "tube covers" (look like little tube sweaters)
           actually increase tube life?
        4. What things are tube amps/pre-amps sensitive to/about
           that might cause them NOT to play at their optimum?
        5. Are tube units more or less sensitive to vibration and
           should extraordinary effort be put into their isolation?
        6. Can a tube amp like I described be placed in an enclosed
           (no back) entertainment center without overheating etc
           or - - must they be in the open air due to heat? (I have
           often seen them called "space heaters").
        7. Am I nuts for even considering getting into tubes?
        I would also appreciate thoughts and suggestions on the S.G.JoLida
integrated amp mentioned above. The smallest of the three amps got some good
ink in Stereophile recently, but that does not substitute for real people 
experience.
Cheers, John
--- Maximus/2 3.01
---------------