Identify tube

How does one identify tubes? There are no markings on a set I have.

qclabrat_102-14-2012 2:23am

jedinite24 Details Discussions Posts This discussion Message User 1,503 posts 02-14-2012 at 03:53pm Copy Comment URL Report Comment Edit Delete Normally I would go to a website like www.TubeDepot.com or www.audiotubes.com and do a visual comparison of the tubes I have vs. what they show. Were the tubes you have from a tube power amp or a tube preamp? Sometimes I've just taken pictures of the tubes and sent them to Brent Jessee or Jim McShane along with some physical measurements of them and they helped me identify them.
davmusic Details Discussions Posts This discussion Message User 4 posts 02-15-2012 at 01:39am Copy Comment URL Report Comment Edit Delete This can be risky. Even if you know it was an audio tube, the missing letters, (e.g.,B,C,GT) can leave you with a tube rated for 350 plate volts, when your amp requires one that may run around 450 plate volts. There is no sure way of knowing this without those letters.
qclabrat_1 OP Details Discussions Posts This discussion Message User 7 posts 02-16-2012 at 12:29am Copy Comment URL Report Comment Edit Delete I'm pulling them from my amp so I know they are EL34s, would there be ones with different voltages for these?