tubes+valves ...?

My Manley sounds pretty good as well...

 

Are there any makes of valves that are regarded as the best quality? Then, are there any valves that one should avoid as poor quality?

I have a X-can v2 that I'm thinking of upgrading 'cos I'm not that impressed........

 

pete mentioned them as well

cheers

 

I would say - make your own.
Ok, I could not have done this without the help of a project team and leader but it was cheap to do, fun and the result is 2nd to none.
In it's 5th year of running and make a beautiful controlled, detailed, dynamic and expansive sound.

My expereince; Avoid Chinese valves.

Tesla and Svetlana make good KT88's.
For input stages (6SN7's on my amp), I have found Sylvania (green label bottom getters) and Kenrad (black glass) in a mix to be the best sounding. How your amp is configured depends what you can try.
Buy New Old Stock (NOS) if you can afford them, but if you can't don't be put off buying 2nd hand on Ebay. I have loads and they have all worked and none have failed so far - that can't be said of the new production Chinese ones I've tried. They are Microphonic (pick up vibrations too easily and make noise out them).
Trying different valves (tube rolling) is part of Valve amp ownership and helps you find what tonal balance and sound you like. I've tried GEC, Raytheon, Rogers, RCA, Kenrad, Sylvania, National Union etc etc. All have their charm.