doctorcilantro Posted October 10, 2008 Share Posted October 10, 2008 Trying to figure out if I have fake Amperex 6922s. I have found the best way to look at it is with a magnifying glass, holding the tube upside down in good light. If you look at an angle the glass allows you to clearly see the letter (acts as a lens); otherwise it is hard to see when looking straight down from above the tube. I have (4) USN-CEP Amperex with date codes etched on the side which appear valid, but the letter underneath is "X" and not "A". I have (3) Amperex PQ white label and two of them have an "A" where as one (whose label happens to be rathered rubbed off) has an "X". I thought they should have "A" or "H" for America or Holland, respectively. many thanks Jonathan Quote Link to comment Share on other sites More sharing options...
Don Richard Posted October 10, 2008 Share Posted October 10, 2008 I can't give specific info on that tube, but there are quite a lot of fakes out there these days. There was an article in a recent issue of Stereophile or TAS about Chinese manufacturing of audio components. That article stated that the Chinese factories had been caught removing ID information from cheaper components and silk screening the correct numbers onto these cheaper parts, which they then put onto the circuit board. This link describes some fake semiconductors and how to detect them. http://sound.westhost.com/counterfeit.htm Your tubes may well be genuine, but be vigilant. The fakes are around. Quote Link to comment Share on other sites More sharing options...
doctorcilantro Posted October 10, 2008 Author Share Posted October 10, 2008 Thanks! I have started a thread on AA as well, and some interesting comments already. One says the X is for Phillips in Sittard. DC Quote Link to comment Share on other sites More sharing options...
HarryO Posted October 10, 2008 Share Posted October 10, 2008 There's also a bunch of fake gold pin PQ's floating around. A buddy of mine acutally paid $300 for a quad of Telefunken Gold pin "vintage NOS". Nasty sounding tubes and clearly typical Chinese crapola as is most of the Chinese stuff. Harry Quote Link to comment Share on other sites More sharing options...
mark1101 Posted October 10, 2008 Share Posted October 10, 2008 The real NOS tube labels will scratch right off easily with your thumb nail. I have heard that the Chinese copies have labels that are VERY difficult to get off. That is what I was told is a good way to tell the difference. I can vouch for the real NOS tubes having the powderly labels that scrape right off, but I have not apparently run across any fakes. I quit buying the NOS tubes a couple of years ago. Quote Link to comment Share on other sites More sharing options...
seti Posted October 10, 2008 Share Posted October 10, 2008 http://www.audiotubes.com/6dj8.htm Where did you buy these tubes? I only use a couple of vendors now. If I buy NOS or close to it I buy from Brent Jesse. He can also help you identify the tubes. I have bought tons of tubes from him. A+ guy. Quote Link to comment Share on other sites More sharing options...
HarryO Posted October 10, 2008 Share Posted October 10, 2008 http://www.audiotubes.com/6dj8.htm Where did you buy these tubes? I only use a couple of vendors now. If I buy NOS or close to it I buy from Brent Jesse. He can also help you identify the tubes. I have bought tons of tubes from him. A+ guy. Ditto!!!Brent is A#1 Quote Link to comment Share on other sites More sharing options...
doctorcilantro Posted October 11, 2008 Author Share Posted October 11, 2008 Tubemonger(.com) tolfd me the symbol under the tube has nothing to do with the production company/facotry. I'd still like to know how these fir into the scheme of things though. The etchings seem like they could be easily forged as well as the labels, which was alreayd discussed; it wouldn't be hard for grey vendors to produce labels that sratch off easily or mimic valid etchings...for that matter they could also copy the symbol under the tube. DC Quote Link to comment Share on other sites More sharing options...
seti Posted October 12, 2008 Share Posted October 12, 2008 Tubemonger(.com) tolfd me the symbol under the tube has nothing to do with the production company/facotry. I'd still like to know how these fir into the scheme of things though. The etchings seem like they could be easily forged as well as the labels, which was alreayd discussed; it wouldn't be hard for grey vendors to produce labels that sratch off easily or mimic valid etchings...for that matter they could also copy the symbol under the tube. DC They could mimic etchings that scratch off but they don't. If the ething comes off easily chances are they are legit. Take some close up pics and send them to Brent Jesse. Ask him if they are fakes or not. Quote Link to comment Share on other sites More sharing options...
Guest " " Posted October 12, 2008 Share Posted October 12, 2008 The problem is not just asian re-labled, but also part time NOS sellers who buy russian military tubes and rebrand them. Manu of the Russion tubes involved are not equiv's and actually have higher heater current requirements. All the more reason to go wuth the major carriers. Parts express works form me. once in a wile I'll do an OEM purchase. I definetly stay away from the 1 man shops.....these folks can not control quality control as well as the major supplers who buy in bulks of thosands. Quote Link to comment Share on other sites More sharing options...
Don Richard Posted October 13, 2008 Share Posted October 13, 2008 An article in TAS, issue 182, said to put the tubes in a freezer for an hour or so. The old name will then become visible. Quote Link to comment Share on other sites More sharing options...
seti Posted October 13, 2008 Share Posted October 13, 2008 An article in Stereophile said to put the tubes in a freezer for an hour or so. The old name will then become visible. I've never heard that one.... Thanks Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.