Nickway, All tubes have an individual sound. How you describe that sound depends much on the associated equipment and how you interpert the tone and other issues such as clarity. For example, I've been listing to tubes for over 20 years. What I consider neutral folks more experienced with SS components or new tube components would probably describe as "warmish".
There has been a shift in the past 15 years or so for manufacturers to enhance the sense of detail. Using the general tone of EH's for comparison, I have found this tube (the EH)to be excessively bright in all applications, except a new amp I just purchased wherein it sounds balanced.
In this amp the new production EH sounds quite balanced and relatively smooth. EI's, which I consider tonally neutral, balanced and having great clarity, sound shy in the bass (which gives them the imediate effect of sounding over bright). Where the EI's have sounded bass shy I have used NOS and current production JJ Tesla's and have added bass, but with the new JJ's the highs take on a bit of roughness absent in the EI's and the NOS Teslas are a bit too warm on top. Then, in this one amp, I tried some NOS EI's with short plates, and found that they were much more balanced in this amp than any of the others I tried.
The moral of the tale is, apart from using your own ears and experimenting, you must know the equipment and preferences of the folks making the recommmendations regarding the sound of tubes before you can apply it usefully to your situation.
