Any experience with Ei/Yugo KT-90s?

[greiswig]

I bought a quad of these guys on EBay, supposedly NOS. One of them had the guide pin glued back in place (seller is sending a replacement), and one of the other tubes no longer biases properly (drifted high).

Just wondering if this is typical or not...hard to imagine some guy at the factory gluing the pin back on.

[M Fowler]

Most likely recycled used tubes and they call it (NOS), but really its just nasty overpriced shit.

Mark

[Alexo]

..they call it (NOS), but really its just nasty overpriced shit.

Mark

There's a country song in there somewhere.

[greiswig]

Most likely recycled used tubes and they call it (NOS), but really its just nasty overpriced shit.

Mark

This based on personal experience with actually-new Yugo KT90s, or Burlington Guitars and Amps, or... ?

[M Fowler]

Just wondering if this is typical or not...hard to imagine some guy at the factory gluing the pin back on

I was unaware I was actually posting factual information Pretty much just in response to your own questions regarding the tubes being NOS and bought off of ebay, buyer needs to beware. Never know what they are selling on Ebay these days.



Mark

[David Root]

The first thing I check in a pic of an alleged "NOS" tube is the flashing. If it is completely bright, with no holes burned thru, it should be good. Not necessarily "NOS" but at worst only lightly used.

If you see any holes ar darker spots that are incipient holes, it is used. I have even seen tubes with pinkish edges to the flashing, or even pinkish sections within, offered as NOS. These tubes are WELL used and if power tubes, are not too far from going to Valvehalla.

Check the pins also. They may or may not be blued from burn in (9-pins) but if they're even slightly bent out of shape, be wary.

Exception: tubes with two or more getters, usually power tubes. I have some used Tungsol 6550s (the real thing, not new Tungsolskis) which have the two side getters looking pretty ragged but the top getter is still perfect, and these tubes test OK. I also have another with two pink side getters and a good top getter that is past its prime. I have a MaxiMatcher tester so I do buy rare used (UOS) power tubes occasionally to save money.

[rp]

Once upon a time someone pulled an old but still working tube and put it in the new box and set it aside for a future tubeless rainy day. These piled up in a box under the bench or in an attic. Then they die, and now you have nice tube boxes with old worn pulls on ebay as NOS. I think this happens a lot.

[Alexo]

Once upon a time someone pulled an old but still working tube and put it in the new box and set it aside for a future tubeless rainy day. These piled up in a box under the bench or in an attic. Then they die, and now you have nice tube boxes with old worn pulls on ebay as NOS. I think this happens a lot.

Or worse, s/he pulled a dead one, but kept it like a little pack-rat.