Question on tube rolling

I actually have a chart that I use and log in the ggod and bad points in my current tubes..Comparing with the new rolled tubes is by comparing the good and bad points of the tubes you are trying to replace..Its just kind of a scoring system..Its better than trying to trust your memeory..

king,
In general I think you can get an idea of the basic characteristcs of a broken in tube with a few minutes warm up though it wont be at its best. Short a/bs many times will draw you to a more initially impressive piece but many times that gear isnt as "musical"I think the best results are judged over time. If you listen to a couple refernce pieces over a few nights then make a change you should be able to tell if you prefer one over the other. If you cant then you can go back to the quick a/b if you still dont have a preference flip a coin.

If you need an instant A/B comparison to hear the difference between two different tubes, go with the cheaper tubes.

Better to give each tube a couple of days in your component due to warm up, breaking in, and general settling. Pick a couple of well known, well recorded pieces and take notes.

If you can't really identify any significant, to you, benefits of one over the other, then go with which ever is cheaper.

Tube rolling is not as easy as component selection in many regards with its virtually instant A/B comparison abilities. I put it more in the lines of IC and cable "rolling". Most changes are going to be quite subtle and take some time to familiarize with while other changes may be more apparent from the beginning, but take time to recognizes all the differences (other than just the obvious). Try to control some of the variables though, like record your volume settings for a piece and replicate that setting when trying a different tube (at least during part of the analysis period). Also do this with an SPL reading, which may end up that you have to change the volume control setting to equal the same sound levels between different tubes. If you are like me, you probably listen at two different volume settings (very general), one moderate and the other loud (depending on my mood and who is around/asleep/doing homework, etc. . ) and compare at both the more common levels. Ultimately you want tubes that are going to deliver what you are seeking at your normal listening levels.

It differs based on the gear you are using, but warmup can be as long as 2-3 hours to sound its best. When you power down, they usually cool off after just a few minutes, or you can use a towel or oven mitt if you don't want to wait. I'd recommend giving it a few minutes.
Yes, tubes need break-in, but most of the ones you will roll to are old stock, and although many will be advertised as NOS, I bet most of them are just used old stock, thus already broken in. Cheers,
Spencer