Give 'em a pop quiz on Monday morning when they least expect it! Sorry, couldn't resist that. Bob is right...unless you're planning to buy bulk or try to find N.O.S. at an out of the way old T.V. repair shop, buy from a reputable and knowledgeable dealer. As the price goes up, so does the counterfitters' motivation! You might also check out www.tubeworld.com...seems to be very well versed with an increadible selection. Good luck!
How can I test tubes?
I am auditioning hybrid phonostage AR PH3 and it seems that sound becomes too worm and dim during approximately 2 vinyl playback time. I need to know before I buy any new tubes if there is any way to test them first. There are SovTek660922 tubes in that phonostage.