Never Owned a Tube Amp and Want Advice


Hi All, 

I have never owned a tube amplifier before and am planning to purchase one with a minimum of 50 watts per channel to mate with 8 ohm 88 dbl speakers.

My hope is experienced audiogoners will share their expertise regarding how to approach this. While I realize listening is the best way to learn about sound and compatibility; I want to learn a better understanding about brands with less maintenance and longer tube life, how to decide between mono or stereo,can a newbie play with bias or is auto biasing a better first choice, etc.

I would also appreciate what to look for in selecting a used tube amp to identify one that might be in need of repair. For example, with solid state depending on the brand, capacitor replacement can be more of a concern. Any advice on what to look out for or ask about with used tube amps would be appreciated.

A big question I have is how to understand the relationship between power tubes like E34's, 120.s, etc. and, I guess the driver? tubes like 12au7's and 12at7's. That  is to ask which is more critical to the overall sound of the amp? FWIW, I routinely tube roll with my preamps.  

I 've read through a number of threads but maybe someone can point me to good ones I may have missed. 

Thanks for listening,

Dsper
dsper
Thought it would be a fairly low cost way to see if I can hear a tube difference
The difference between tube and transistor is usually pretty easy to hear. I've had people walk in from off the street and they were able to tell the difference. I wouldn't worry about that!
A nice place to start.  What brand/number tubes came with it?
  One quad of Penta Labs KT88SC, and one quad of JJ 6550. Seller claims they all test around 75 on his Knight KG-600.

...they were able to tell the difference. I wouldn't worry about that!
You are probably correct, but any time I think I know 100% what I am doing is when I find out I learn something new!
  
@dsper 
A positive comment in a 2009 Absolute Sound test article, fwiw: 
http://www.theabsolutesound.com/articles/tested-conrad-johnson-et2-preamp-lp66s-stereo-power-amplifi...
"When it comes to imaging, the LP66S evinced plenty of tube magic. Image outlines were solidly anchored within the soundstage. When partnering the ET2, it easily kept pace in this respect, giving full scope to a deep and spacious soundstage."
pkatsuleas  wrote: Unfortunately, can't afford any Tannoys right now! ;-}
They seem to be catching my eye lately as well, though I have never heard them. Seem to have a high cost even used.