Vintage Mesa STR 12AX7s...who made them?

[SonicProvocateur]

So I have 4 very old Mesa tubes.

Two are early Mark III era (late IIC) 12AX7s
One labeled Mesa STR 12AX7 in white large print
the other same age; Mesa SP12AX7 (7025) (pre-rubber covering)
another of the same age; Mesa STR 12AT7

the last is a few years younger, probably the first run of the SP12AX7s with the rubber covering over it; definitely pre 1990.

So my question is what manufacter's are these tubes?

 

[FXR]

I don't know if someone knows from a list and the date, but looking at photos will get you zeroed in quickly. Got any pics of the tubes or can ya take some and post um?

 

[SonicProvocateur]

I don't have a hi-def cam. I'll try and take the best pics I can though. A couple are in my amp...

 

[FXR]

A general picture of the plates inside will be a big help. Do the best you can.

 

[SonicProvocateur]

The STR, The triode plates are very complicated with a clear top. The getter is square.

The STR AT7; labeled as ECC81. Short plates with white tops and bottoms. Top halo getter is HUGE!

Rubber topped STR, Also has very complicated triodes. Can't see the getter.

I didn't get a picture of the 7025 because it's currently in V1 of my amp and it's a pain to dig it out of my rack. I'll get a pick when I can. I KNOW the labeling is the same as the first 2 but I don't know what the plates and getter look like; I recall it having a halo though.

 

[FXR]

I'm walking out the door, but with the looks of the mica we can see, we'll be able to match them to a production. I use google images and put in the mfgr name and tube type and see if any match and create a list of what the tube likely is. Sometimes there's more then one option and you have to find more info on what Mesa was doing at the time.

Gonna see a bud jam. But I'll catch up later.

 

[SonicProvocateur]

Found this auction for a 7025 like mine, though I still haven't pulled it. You can see the complexity of the triodes.


http://cgi.ebay.com/VINTAGE-MESA-BOOGIE-12AX7A-ECC83-PRE-AMP-VALUE-TUBE-/250742856743?pt=Vintage_Electronics_R2&hash=item3a61705c27#ht_500wt_1156

I'm thinking it's probably an early russian design? I really don't know; I haven't seen a US tube like it before...

Now, I do think the AT7 is US, looks like a Phillips to me. Maybe even a Tesla....Dunno, seems pretty quality by design though. Haven't tried her out yet.

 

[212Mavguy]

First and third pics are most definitely Chinese manufacture. Middle pic is too blurred and the plates/getter are not easily seen due to label printing being in the way.

 

[SonicProvocateur]

Yep, I did some digging around and found that the 7025, STR and probably the SP are Chinese 7025 "Silver Specials" or 7025SS, falling somewhere in the gen 5 tooling.

It seems through digging around they are pretty highly regarded as the cream of the crop in NOS chinese tubes; i'd be pretty quick to agree. They sound amazing.

I still don't know about the AT7; i'll try and take a better picture.

Edit: Mine are different from the Ruby versions; the Ruby's have halo getters and mine are square.

Ruby (new issue) versus an ENGL labeled same design.

I'd also like to add I think Groove Tube issues the same tube in their Chinese series tubes too (I think, it's hard to tell from online pics)

 

[94Tremoverb]

NOS chinese tubes

Lol...

What next? Vintage Chinese guitars?

Just because something is old doesn't make it good. If anything, Chinese tube production has increased in quality over time (it couldn't really have got any worse than when they started), and calling *any* Chinese tube "NOS" just because it was made a few years ago and hasn't been used yet really makes a nonsense of the whole point of why *real* NOS tubes are worth having.

Keep it for American and European tubes made before the mid 80s, that way it really means something worth having.

 

[SonicProvocateur]

Not to be too argumentative, but considering these are close to 30 year old tubes, and put head to head against my modern chinese tubes (TAD selected, no name sinos, various Ruby's, and some marked Mesa Chinese-1's) these truly are better tubes in bandwidth, responsiveness, gain and microphonics (with the exception of the Mesa Chinese-1's which have pretty similar gain, but very different bandwidth).

I'm not arguing that Chinese tube production has increased in quality over time; i'd say it waxes and wanes a bit...I hate about 50% of all the Ruby tubes i've ever touched, but all these Mesa STR's are very good and i've put well over 1000 hours on the first STR and it's holding strong (got it with the amp). The modern Mesa Chin-1 is already going out.

...and personally, I hate Sylvania 12ax7s. They like pure mud (and yes, I'm running STR-415s). You're right just because it's old doesn't mean it's worth having.

 

[94Tremoverb]

I'm not saying that they might not sound better than newer junk tubes, or that all old-production tubes sound great as a matter of taste (I personally don't like Telefunkens, and they're about the most 'desirable' of all), but calling *any* Chinese tube "NOS" even if it's twenty years old is just wrong. The term NOS was originally used to describe old-production US and European-made tubes, to distinguish them from new Russian and Chinese tubes, and that definition should still apply because it's how well the tubes are made that matters not how old they are - tubes don't improve with age in storage.

Are early Japanese Tokai and Squier guitars vintage now just because they were made in the mid 80s? They were pretty good then too. Or are they just slightly better than new far-east models, and still not really comparable to 1950s and 60s US originals?

 

[SonicProvocateur]

I see your point, and agree with the age and storage perspective.

On that note, I definitely hate when people call the new production Mullards NOS when they are clearly new production. Very frustrating indeed. They are not "New Old Stock" they are new new stock.

Back on point to my original question. I would still like to pin down a manufacture of the STR 12AT7 ECC81. I'm sorry, I do need to take a better picture still.

 

[SonicProvocateur]

Bump topic for identifying the STR 12AT7. I finally got a better camera, and better pics!

JAN PhilipsECG maybe?

 

[MrMarkIII]

"New Old Stock" also means the tube has NEVER been used. It was manufactured many years ago and has sat on a shelf somewhere since its manufacture date. The military stockpiled thousands of tubes, and never used thousands of them.