Vacuum Tubes - Chinese knock offs being sold as NOS?

They are most probably real ones, this tube was made in abundance in early 80's, for military or air force, came in white boxes, with cigar wrapping, so dates 83-14 are not funny, it came under all names CV4024, M8612, 12AT7WA and so on. Vendors are all over the place and master packs are in hundred.

Best way to check if fake only looking the construction.

They may also be rebranded but that does not subtract for being the real thing.

One thing that cannot be rebranded is etched codes at bottom of glass.

There are a number of quality vacuum tube retailers. The price savings from unknown sources is just not worth the few dollars saved.  

I agree with Russ. Pay a few bucks more and buy for reputable sources. 

Petgo is most likely spot on.

The market was flooded with these starting around 2002/2003 with pics of huge master cases (both in individual white boxes and boxless).

I purchased 2 pairs from the UK (white boxes -w- black print/tubes wrapped in thin paper/black plastic wafer shaped pin protectors on the bottom).

Sound was awfully thin/bright driving 2A3's in my Bottlehead amps, but some liked them in different applications.

I gave them to others to try, but think that one pair was returned.

Mine were dated 1983 or 1984 (forget which) and the etched code was for the Mitchum (sp?) plant.

DeKay

Only buy from 2 vendors in USA.

EBM:

Do you have a preference - Jeff or Akbar?

DeKay

Thanks for the feedback everyone and also the history lesson.   My take away is that they are legit NOS tubes from the mid 80's, but not necessarily the end all in sound quality.

Can anyone offer any comparisons between them and current manufacture Russian and Chinese tubes?

Thanks,

Dave

"Strange that this paper is not yellowed at all as it would for 40+ year old tubes"

I have some 50's  tubes with original packing paper that is still pliable and appear relatively untouched. 80's tube are practically newborn!

It  depends where they were stored.

Dave:

What amp/preamp will you be using them in and what type of sound are you looking for?

If you are using the amp now - what tubes are in it?

I've mainly only used them to drive power tubes if HiFi amps and also to drive Fender reverb units, so won't have rec's for other spplications.

In my older Bottlehead power amps I swap the 12at7 (driver) depending upon what 2A3 power tubes I'm running (have 2 types of RCA, Visseaux and Ken- dual flat plates which all sound different from one another).

Spent an afternoon (long time ago) rolling power/driver/input tubes (EL84/EL34/12ax7/12at7) in a couple of Jolida amps and the same was true.

I also use 6201 variants of the 12at7, but don't know what the difference is - if any.

My go to for the extremely fat sounding Ken-Rad 2A3's are RFT's (a tube most people don't care for in;-).

For the much/much lighter sounding Visseaux I use RCA black plates with an odd wiggly shape @ the top of the plates.

For the gray and black plate RCA 2A3's I usually use RCA black or gray plates, but some have a squared off shape @ the top of the plates (think all are from the late 50's/early 60's as I as I started using them around 1963 in Fender amps).

I've also used Amperex/Holland 60's production in place of the RCA's, but my tube storage cabinet is currently blocked by stuff I'm not up to moving - so can't check the details on them.

Have various Telefunken/Mullard/Siemens/GE/Sylvania et cetera on hand, but they were not my favorites and ended up being stored away.

DeKay

DeKay,

Thanks for your detailed and thoughtful response.  I have several vintage USA types (GE, RCA, Tung Sol).  

The immediate purpose of these tubes would be in the phase splitter of a mono power amp, so perhaps not as critical position as say in a pre-amp.

I was thinking it might be interesting to try a Euro made version.  Mullard is a respected brand of GB tubes, so when I saw the first add for them, NOS military, that seemed like a good option for a good price.  I thought someone might have come across a box of them that typically does not sell tubes and was selling them at reasonable prices to move them.  When I saw 7 similar adds of different sellers from all over the world ... well you know the rest of the story. 

Plus some of the pictures that are not identical across all adds, the lettering on the tube seems to be chalky (typical of NOS tubes) and bright and solid on others.

I think I will try a Euro tube, not sure I will try the Mullard ones discussed in this thread or not.

Since I do have a tube test system that can fully test all tube parameters, I tend to shy away from "pro" dealers as I can do the matching and weeding out myself.

Thanks again for your thoughts.

Dave

I understand your take/position, but if you only need a single you can purchase a properly tested Amperex/Holland one from Brent Jesse for $60, or so.

Purchased gobs of good tubes on Ebay 20 years ago (as well as loaded tube caddies locally) for close to ZIPPO, but those days are gone and past.

DeKay

There are still good deals out there... even on the big site, though you are correct, they are getting harder to come by.

You are correct about the Amperex/Holland IBM stuff on Brent's site.  Still some good deals there.  Might try a couple.

I got answers from most of the vendors I contacted about the Mullard military tubes... none of their answers gave me much confidence.   Too many red flags for me, some listings for those tubes seem legit, but most do not.

Caveat emptor

I always buy tubes from Brent Jessee - his recommendations have alway been spot on so far, and while he isn't the cheapest, I can trust him.... 

++++ for Brent, he is hyper trustworthy. I also use Andy at Vintage tube.

Mullard 60’s Blackburn phase splitter in my extensively modified MC240… from Brent, totally transformed amp from the admittedly tired (72%) Tele.

Have fun !