As a side note, watch out for eBay sellers who offer "NIB" (new-in-box) or "NOS" tubes in "original" boxes. Some of theose boxes are reprinted stock white tube boxes. You can usually tell when you see white edges outside the original labelling. Another tell is identical coding on the inside flaps of the box, indicating there were printed from an image of a single box.
For Tube Folks...
Hi All,
I am rather new to tube gear and recently purchased a 'NOS' GE 6550 Power Tube.
A. It was advertised as: "New old stock in original or OEM box. A nice USA tube that will outperform any current production 6550 made. An excellent lot, matched to within 5 percent and then aged in a hi-fi shop demo unit. Very low hours, burn-in time only, and the performance has been verified by us..."
B. The seller also sells used GE6550 tubes that are advertised as: "Light use, tested good with good match, and white box..."
The large black spot on the glass where it GE is etched makes wonder how many hours of usage this tube has seen...
My question - Within reasonable certainty, is this tube is NOS or is it USED?
Thanks in advance for any clarity.
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- 43 posts total
Hi All - I really appreciate the information. A special thanks to @ Viridian for mention the "The straight glass, three getter tube has a side getter so will have silvering on the side in addition to on the top" I do not want to delve into the what constitutes 'NEW' or 'USED' conversation at this time, but that may be a worthwhile string someday... |
@inagroove Just look at the pins of the tubes. If you see scrapes along them the tube has been inserted into sockets a few times. An NOS tube will have no scrapes. |
The pic you show has a very large side-getter patch (good), with light-gray fringes that indicate some light use - roughly consistent with the seller’s description. As use continues, the side patch typically shrinks (well before the top patches), with the fringing sometimes becoming more dominant. I have some GE 7581A with chrome side patches and NO fringing, that are probaly truly NOS. Anyways, to see a very large side getter patch on a power tube (dark metallic or chrome, NOT chalky white/gray or brown) is usually a good sign. (note: if you see a side patch on a tube that shouldn’t have a side getter, like an EL34, that’s bad news lol) The debate on "NOS" nomenclature is boring semantics. NO I wouldn’t call this tube strictly NOS, but these days very few tubes left are. If the seller’s description is accurate, and seller can be trusted, I’d be happy with ’em. |
+1 atmasphere I examined the pins when I cleaned them. All showed light-ware - a sheen that indicated they were inserted into a socket. I was not alarmed because the seller's description indicated that they had been tested and had some burn-in hours. Perhaps I should have thought twice... "An excellent lot, matched to within 5 percent and then aged in a hi-fi shop demo unit. Very low hours, burn-in time only, and the performance has been verified by us..." Regards, |
- 43 posts total