Help me Identify these Tubes!

[Sonicolone]

I came into some older tubes and I need help identifying them:

1. An EL84 out of a Vox amp. It is identified with "El84, PE89, A2JN1." Obviously this is a rebranded tube, but from who and where? I have two of these.
2. A GE 12ax7 of unknown origin. Is this a good tube?
3. A mystery 12AX7 that appears to be an RCA but is it?
4. A 12ax7 I am pretty sure is n RCA - looks like a black long plate, but please confirm.

Are these decent tubes? Any help would be GREATLY appreciated!!

[DRH1958]

The RCA you think is a black plate is a black plate. The trait of these is that they are not shiny like Raytheons. Kind of a dull black. The 12AX7 in the eight sided figure. Tung Sol did this too, but this is an RCA.
For the EL84, look at the bottom of the side, not the very bottom down underneath by the pins and see if there is smaller writing etched into the glass. There should be a line of three letters and numbers and below these there should be four, the first being a symbol, most often a triangle. Does the top of the tube have either two or four seams in it? Looks like an Amperex.
The GE is a good tube but they usually sell for less. I personally think they are good. It's a long plate.
I don't know about the mystery tube, don't recognize the plate structure. RCA had their 12AX7 inside that elongated eight-sided figure like the black plate. Look at this and compare. Could be a Japanese made tube. Matsushita or Hitachi. I don't think RCA had those trapezoid shapes holes along the sides of the plate. If they all test good, they will sound great if they are vintage late 1950s to late 1960s.

[Sonicolone]

Thanks, the bottom of the EL84 says "K M 4" and then underneath that, there appears to be a symbol that resembles an upside down "U" with a dot in the middle, a squiggly character that may resemble a "9" and then another character that kind of looks like a "J." The top has four seams. Does this help? Also, some more pictures of the mystery 12aX7 are attached. Thanks!

[DRH1958]

That upside down U with a dot indicates a Yugoslavia made tube, which is an Amperex. I have a few of these and mine say "Made in Germany" on them. The four seams seals the deal. They are definitely Amperex tubes. One of the best EL84s ever made. Score!! The two extra pics you posted still leave me wondering. Can you get a shot of the "12AX7" printing?
BTW, here is a link to the codes for Amperex/Mullard. Scroll down to the bottom: Mullard, Philips, and Valvo Tube Codes

[Sonicolone]

At the top of the mystery 12ax7 has a small metal tag soldered on one of the halo support posts that is stamped "35"-this is the only marking on it I can find! Thanks!

[DRH1958]

This identifies this tube as a Tungsram tube.

[Enzo]

Be careful when you ask are these "good tubes". Some brands may be generally preferred by tube heads. But tubes are not generic. Telefunken may make great tubes, but individual Telefunken tubes can be noisy, microphonic, low gain, etc etc. Likewise crummy undesirable brands of tubes may individually shine. It is like claiming that all blondes are dumb. Some may be, but not every one. So the real answer to "is it a good tube" is to plug it into and amp and find out how it sounds, not just looking at the label.

[Sonicolone]

Be careful when you ask are these "good tubes". Some brands may be generally preferred by tube heads. But tubes are not generic. Telefunken may make great tubes, but individual Telefunken tubes can be noisy, microphonic, low gain, etc etc. Likewise crummy undesirable brands of tubes may individually shine. It is like claiming that all blondes are dumb. Some may be, but not every one. So the real answer to "is it a good tube" is to plug it into and amp and find out how it sounds, not just looking at the label.

Understood - what I wanted to know is if these tubes have the potential to be great, with the caveat that even well regarded tube manufacturers serve up duds. Thanks.

[DRH1958]

Yep, get them tested, preferably a mutual conductance tester like the Hickoks and others. But it has been my experience that vintage tubes add harmonics and fuller sound than most current production tubes. I had a Peavey Classic 30 and I replaced the Sovteks with a good set of vintage tubes and it was like having a new amp. But yes as Enzo said, listen instead of look.

[Sonicolone]

Ok so I had them tested and, while I don't recall the exact results, the 12AX7s tested in the "64-70" range and I believe that the El84s tested in the "70's" - I have no idea what that value means or relates to, but on the meter, it was well in the green or "good" range.

Is this the expected range?

I have verified that the EL84s work in my amp, but I am not in a position tonight to crank my amp to really get a feel for how they sound - tomorrow they will be full bore!

[Enzo]

Tube tester numbers don't mean a whole lot. if one 12AX7 measures way different from the others, then it may be bad. But within 10% of each other like you report is fine. As long as the tube isn't shorted out, if it wants to work at all, just put it in an amp and see how it sounds.

[km6xz]

Plus, how it "sounds" depends on the complex relationship between the circuit is in and the tube being just one of the variables. A "great" tube might sound worse than a "bad" tube in another amp circuit. Those who claim some sonic trait can only truthfully say anything referenced to the amp they tried it in, and guitar and playing style. If those variables which have more impact than a tube can have, are not mentioned, ignore their advice. A tube that amplifies is good if it pleases you in your individual amp, in your unique acoustic space, being played in your unique way. That is why real masters of the guitar do not care as much about mojo claims and play anything the company endorsing them makes and still sounds like them alone. Tube rolling is a hobby fully independent from music or electronics, an expensive hobby.