Any Vintage tube Gurus around? ID this?

[LeadedEL84]

I'm no NOS tube expert, but I understand that relabeling of brands was a regular practice, so your "Magnavox" tube could have been made by RCA, Sylvania, GE, Tung-Sol, etc. It helps to have a couple of good photos, because it's the construction of the tube that the experts look at, as opposed to the label on the outside.

Thanks for the reply, voodooman. I posted a picture of the tube. I added it to my original post.That is the only picture I have to post until I take the amp apart again to switch tubes. I don't know why those extra spaces with Xs showed in the post. I only attempted the quick upload and post once.(?)If that is not sufficient maybe one of the tube experts can let me know what parts or angles they need to see. Might be a day or two until I tear the amp apart again. If it's one thing I dislike about these V series Crates it's the tube access. What a pain! I didn't have this problem when I was a Fender man.LOL

I knew this was a relabeled tube made by one of the big manufacturers. I had never heard of Magnavox being a manufacturer of tubes themselves. I know that RCA is one of the favored American tube makers for guitar amp use. I know that some others are better for radio or high end audio use and are too clean and sound too bright or brittle in a guitar amp. I was expecting this Magnavox to turn out to be one of those type of tubes because I associate that name with TVs and radios rather than guitar amps. It was a pleasant surprise that it is so harmonically rich and balanced. That's why I am curious to know who made it.

[LeadedEL84]

After hours of reading dead end forum and discussion entries given to me by Google I have only run across a couple references to the Magnavox tubes. One mentioned Sylvania and relabeled Magnovox tubes but the actual artical was no longer there. Another mentioned Magnovox 12AT7WA and RCA 12AX7WA tubes as being war time issue. But again the only text I was able to read was the Google search summary. The actual artical it took me to had nothing about Magnavox.

I just found some relabeled Magnavox 12AX7s made by Tung Sol with"Made In USA" stamped on the side( is that right?) and British made Mullards stamped Magnavox. Still tells me nothing about my 12AT7. Sounds like Magnavox bought from many sources

[tunghaichuan***]

DVM is correct. Many companies bought tubes from the major manufactures at the time and relabeled them with their own logos.

To muddy the waters even further, major manufacturers of the time would buy tubes from each other rather than tool up for a new run of tubes. I have RCA-labeled tubes marked G.E., for example.

The tube in the photo looks like a GE to me. Are there seven little dots etched into the glass below the "12AT7?" If so, then it was made by G.E.

[Bloozcat]

You might try some of the Ampeg forums and look for some pics of tubes there (if you can find any). Magnavox owned Ampeg for a period in the '70's and they re-branded a lot of tubes as Magnavox. Of course, it's possible that they did the same thing for tubes they used in their TV's as well.

It might be a start...

[LeadedEL84]

DVM is correct. Many companies bought tubes from the major manufactures at the time and relabeled them with their own logos.

To muddy the waters even further, major manufacturers of the time would buy tubes from each other rather than tool up for a new run of tubes. I have RCA-labeled tubes marked G.E., for example.

The tube in the photo looks like a GE to me. Are there seven little dots etched into the glass below the "12AT7?" If so, then it was made by G.E.

That would explain this GE labeled tube I have. It has black plates and looks identical to the black plate RCA with D getter. I noticed the GE had black plates last night but I am looking at it side by side with the RCA now. It looks the same. I am going to look up the test results from both these tubes. I was provided the test results for each of these individual tubes when I bought them. It turns out I have 2 black plate RCAs in the bunch. Might have 3 if this GE turns out to be a relabeled RCA. Makes me want to look closer at all of them and compare likes and differences. I kind of jumped into this vintage tube thing head first. I didn't realize how complicated it was going to get. Kinda fun though.
-also-
Thanks for the suggestion Bloozcat. I will look into the ampeg connection. I will also look for the bumps tunghaichuan refered to on the Magnavox tube when I take it out of the amp to test some of these others.

Even if I don't find a definate answer to who made this Magnavox tube,at least I'm learning some things about the other tubes I have. This is a crash course in vintage tubes. LOL

Out of curiousity: What are some of your favorite vintage tubes and what applications do you use them in?( ie: what positions and for what amps?)

[Bloozcat]

...Out of curiousity: What are some of your favorite vintage tubes and what applications do you use them in?( ie: what positions and for what amps?)

These are NOS tubes that I currently own and use.

Pre-amp tubes: NOS JAN Philips 12AX7WA, NOS GE 12AX7WA, NOS RCA Blackplate 12AX7A, NOS BEL 12AX7 (Made in India for Mil use, same design as Mullard Blackburns), NOS Tesla (not JJ) ECC83, NOS GE 5751, NOS JAN Philips 12AT7.

Power Tubes: NOS JAN Philips 7581A (upgraded 6L6GC), NOS Polam/Telam EL84, NOS Tesla Roznov (not JJ) EL84, NOS Russian Mil. 7189 (6P14PEB - Mil grade EL84 type).

Rectifier Tubes: NOS JAN Philips 5AR4, NOS GE EZ81.

After standing idly by and watching the old standby NOS tubes disappear (GE, Mullard, Tungsram, Tung Sol, et al), I started buying NOS tubes that were still considered "deals" at the time. When deals came along on the remaining US made tubes I bought. When the deals came along on the lesser known foreign tubes, especially the EL84's, I jumped on them. So, I have enough NOS tubes for my short term needs (long term for EL84). Fortunately, the market for newly manufactured tubes has greatly inproved. With guys like Mike Mathews buying up old NOS names like Tung Sol, Mullard, Genalex and making tudes under these names in the Reflektor plant at Saratov in Russia (that he now owns), the quality levels of these "new" old brand name tubes has improved markedly. And tubes produced in the Shuguang plant in China are getting better by the year.

NOS was always the way to go for good tubes. But, with the out of reach prices on what's left in that market, and the great improvements in the new manufactured tubes, I think I'm finally done buying NOS. I'm priced out of that market...it was inevitable.

[LeadedEL84]

Cool man. Sounds like you have a pretty wide selection there. A couple of those I don't even know that I've heard of before.

I have to agree with you on the new production tubes coming out of the Reflektor plant. I think it's called New Sensor now? My first couple go arounds buying new tubes were Sovteks or Groovetubes and then I tried Electro Harmonix. That was back in the early 90s. I wasn't real impressed with any of them. They never lasted that long. My ear wasn't as developed then but I don't remember the tone being great either. I stopped playing for a number of years. I started playing again in about 2000 but was playing solid state amps for 4 or 5 years. Then I got a used tube amp and it wasn't long until I had to replace the original groovetubes. The only EL84s the dealer had in stock were Electro Harmonix. He assured me they had improved so I bought those and the matching 12AX7 preamps. Played that blues junior for about three years before I sold it. The tubes lasted and I liked the tone. I liked the new JJ/Teslas for the Fender Deluxe reverb reissue I had for a while. That's what it had when I bought it and I never changed them. I am really happy with the Tung Sol 12ax7s and E.H. EL84s I put in my USA V 30. The combination seems to be working well.
I'm now learning about the vintage stuff. Messing around with it for my little 5 watter. Mainly because the good deals I got on these tubes. I can't really afford to become a vintage convert. But hey at least with this little amp it's only 2 tubes per replacement! I'm going to have fun and experiment. I'll put a couple power tubes and a couple pre amps back for future replacements.