Tube Testing

[unclej]

i recently acquired a superior instruments co. tc-55 tube tester. i also have an ampec gemini-II tube amp. two of the tubes in the gemini are phillips 7591's. the tube chart that came with the tester was printed in 1956 and doesn't list the 7591. is there a conversion chart that might give me an equivilant tube number from back then that would test the same as the 7591? there is a socket on the tester that the 7591 will fit.

[Southpa]

It doesn't show up on my Jackson-49 either. Then again, my machine is from the same era as yours. Got it at a garage sale for 5 bucks! But here is a little help. http://www.vacuumtubesinc.com/info.html Unfortunately, the 2 "alternates" mentioned (7868 & 6GM5), aren't on my machine either and likely won't be on yours. But its good to know what else would work. I guess you should just take them to someone w/ more modern equipment, .

Edited November 29, 2004 by Southpa

[unclej]

i didn't give much more than that for mine. maybe we're being punished by the tube gods for being cheap.

those alternatives aren't on my list either but thanks for the link.

[Paul Marossy]

I'm not sure that there is an equivalent for that tube. It seems that a 6L6GC or a 5881 is closest to the tube in terms of performance. However, the pinouts are different from the 7591 according to this page: http://www.triodeel.com/7591.htm

I would try to do a search for the owners manual on that tube tester. If you can find that, then you may be able to get an updated tube list from that same source. That's what I did with my EICO tube tester.

Good luck!

[Southpa]

And here is the base diagram for the 7591, .

http://www.nostalgiaair.org/tubes/7591.htm

Edited November 30, 2004 by Southpa

[unclej]

thanks all.