How To Spot a NOS 6550 / KT88 Vacuum Tube

This video highlights the most popular 6550 and European KT88 tubes that are new old stock. These tubes are used in hi-fi as well as musical instrument amps, and the vintage tubes are by far the best. This video gives close up views of the rarest types, and shows how to recognize a modern fake.

Category:

Science & Technology

Tags:

• KT88
• 6550
• Genalex
• G.E.C.
• Gold
• Lion
• vacuum
• tube
• electron
• Mullard
• GE
• Sylvania

[piano25]

Hi there - I currently use Svetlanas on my Audiopax Amplifier. How would you describe the musicality of those babies? :) British vs Russian vc American?

By the way what would be the price for a GE tube like that?

Thanks!

[audiotubes]

Russian tubes are generally louder but thinner in sound. The British are just the opposite, warm and rich. The USA 6CA7 are in between, with great power and nice music reporduction.

[audiotubes]

Hi, stay tuned, more to come when I can find the time. I was a radio disc jockey years ago and I guess the voice stayed with me. I am from the Chicago suburbs, but I guess the radio voice accent is more like California!!

[MovieTech]

@hsvdt If the 6550-in-the-octagon is gray or silver (NOT white) and it says USA below it the tube was made by Tung-Sol.

[hsvdt]

i bought an old new zealand made amp from the 70's a little while back, i believe its still got its original tubes, my main issue is trying to ID them. its a coke bottle design with IEC (in dark blue 3D block letters.... from memory) printed on the metal, brown mica wafer and all 3 shiny getters, with the stop sign 6550 on top. If i recall correctly, its a tri hole. now there are no other numbers i can recall. Any ideas? Is there an email address i should use to send images to for better ID?

[robertgift]

Well done video!

Does getter get H and He that migrate through the glass envelope?

Or will old tubes have gas and not work well?

Thank you.

[fluff191]

Man I love tubes. Great video.

[Beatlewayne]

YOU ROCK Audiotubes and now, so can we. On behalf of all who are interested thanks very much for for "de myth tifying" some of the basics. via an excellent tutorial.

Love Always

Beatlewayne.

[MovieTech]

No examples of the Sylvania-made 6550?

[conjering]

Can you give me your opinion on the reissue Gold Lion GEC KT88, and what is the JJ KT88 a copy of.

Thanks

[hsvdt]

i have what i THINK may be an NOS tung-sol three hole, however on the side just on the metal section below the glass housing, it has in big bold ink printed 3D letters CEI not IEC it has the same stop sign on top with 6550 mostly faded, and warn off. it came out of a mid 70's holden/wasp amplifier. any ideas?

[jigibao]

masage placment mistake ,nothing to worry abaout..