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What's your favorite 12ax7 and why?

pilotputz

pilotputz

Super Member
Having rolled quite a selection of old stock 12ax7s I have come to prefer black plate Raytheons; specifically the bent square gettered 12ax7s from the late 50s. To my ears they sound very smooth and rich. They have great detail and are not at all crass or overly bright.

I've owned both smooth and ridged plate Telefunkens and think that they are sort of thin and bright. Am I the only one that feels that way? When I see how much they go for on ebay I think I must be!

Mullard long plates sell for a bunch as well! I think they sound sort of dark and not as detailed or as open as the Raytheons.

I really like early long plate GEs. I think they are very underrated. They have a super sweet and open sound and can be had for a great price.

I think the short grey plated RCA 12ax7a is an excellent tube as well. To me they sound chunky and rich. I hear guitar guys like them as well.

I keep hoping to cross paths with Sylvania black plates. I've heard good things about them. I have several pair of 50s short grey plates and think they sound good, but not as good as the GEs of the same vintage or the Raytheons.

I was hoping to get some input from you very knowledgeable AKers on other 12ax7s a fella should try as well as your opinions on the tubes you prefer with your gear. Thanks!!
 

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I briefly tried Teles in my 6V6 monos and came to the same conclusion as you. They sounded tizzy on the top end, to my ears. I ended up with Voice of Music badged 12ax7s in them. I don't know who made them, though.

I've rolled at least a dozen 12ax7s in the Almarro, and the GE black-plate 5751 came out the winner.
 
I know what you're saying, gogofast; but I'm pretty sure the secret's out. Even the thrift shops are starting to overcharge for gear nowadays!

It reminds me of Don Henley's lyric from "The Last Resort", though. "They called it Paradise. I don't know why: Call someplace Paradise, kiss it goodbye."
 
And does any of these provide the answer if the equipment the tube is used in is not mentioned. I would think there is a big difference based on this equipment. Synergy...
 
How different manufacturers 12AX7's actually sound is a highly speculative topic.

Everyone hears differently, and the circuits into which the 12AX7's are placed have various different designs, and different passive components made from different types of materials that can easily alter the end result we hear. Not to mention the many circuits out there that are simply running way out of spec.

There are just SO MANY variables, many people cannot obtain a fair listening test for a particular tube on their equipment.

However, I prefer the overall sound of Telefunken 1961 smooth plates; as far as vintage tubes are concerned. I have always found them to be smooth sounding and never thin or harsh. My second vintage manufacturer choice is Sylvania's 1961 low-noise tube they made for use in Baldwin tube organs. High gain, low-noise, and a punchy low end.

New production overall favorites are the Cryoset varieties of the Ei 12AX7EG, and the Electro-Harmonix 12AX7EH. The Cryo process is fairly good at weeding out the smaller 'preamp' tubes that aren't up to par, simply due to the rigors they undergo between the burn-in, the cryo process, and the annealing treatment thereafter. The best part is that they can generally be purchased for nearly the same price as a non-cryo'd tube.

YMMV.

. . Falcon
 
I would think tube placement more important than the brand of gear you're using. For instance, I can't hear any difference in the 12ax7s that I use in my Pilot 232 amp, but I can absolutely tell the difference in the 12ax7s I use in the Pas 3x preamp. I have also rolled tubes in integrated amps and find the same thing: The front end tubes are far more noticeable--to my ear, anyway--than the power tubes or rectifiers.
With that said, a tube is a tube is a tube. I find it hard to believe that one distinct tube is going to sound different or exhibit entirely different characteristics if it's in a Fisher amp instead of a Scott or Dynaco or whatever brand you run.
 
Urizen said:
I briefly tried Teles in my 6V6 monos and came to the same conclusion as you. They sounded tizzy on the top end, to my ears. I ended up with Voice of Music badged 12ax7s in them. I don't know who made them, though.

I've rolled at least a dozen 12ax7s in the Almarro, and the GE black-plates came out the winner.

Coincidence?:D
Click to expand...


Do the VMs have any etched dots on them Ken? I was thinking they were GEs.

My thoughts on 12A*7s is that all of the old ones were good if you got the right tube in the right circuit (ala rolling). As far as new offerings the Sovtek LPS, Mullard reissue, and Tung-Sol reissue are pretty decent.:music:
 
I've got some GE blackplates coming for my Almarro, based on your recommendation, Ken. Till then, the Fisher-branded Mullard is keeping me happy.
 
In my preamp the phono stage uses two 12ax7s. The guy who sold me the preamp sent it to me with cheap chinese tubes that tested "replace" but still worked but I got rid of those. I first got a couple of West German Amperex's which I think were made by Siemens which are good sounding tubes. Currently I am running a pair of Dynaco branded telefunkens which sound very good to me. I just got two pairs of Raytheon Long Black Plates with 1960 date codes which tested good but I have not tried them yet. With the prices of NOS tubes going up I am buying some extras lately for a rainy day and had heard good things about the Raytheons. Also bought a second set of Dynaco branded telefunkens last week. I figure all those should last me a while.
 
Hey, RWFE!!
It sounds like you've got a nice little collection of 12ax7s going!! Sometime when you get the chance you should swap out your Teles for the Raytheons and see what you think.

You're certainly right about having enough tubes to last you a while: They say that Telefunkens just about last forever! But then the Raytheons aren't too shabby either. I picked up a pair over 2 years ago and just retested them several weeks ago and they haven't lost any of their tested strength in at least a thousand hours of use! I have no idea how long they will actually last, but I've certainly had enough time to find to find spares for when they do finally fail!
 
I haven't heard all the permutations that are out there. But my fondest memories of 12AX7s were in an Audio Research Corp. SP-3a1.

So orange globe Amperex. They pictured them in all their advertising and owner's manuals.
 
Just about any 5751!

All kidding aside I'm not a 12ax7 fan and generally any 5751 sounds better to me.

As to the Telefunken bright/thin thing I whole hartedly agree, but there's a place for them,
the original circuits they came in, the vintage stuff that used them sound best with them in
there but put them in a modern piece and you get the thin/bright many accociate to telefunken.

When I HAVE to use a 12ax7, I am generally (gear/system dependant that is) going Amperex way.
 
Pilotputz,
You are right I probably got enough 12ax7s to outlast me and the preamp at this point. I plan on trying the raytheons have been in a lazy mood lately. This has motivated me to try them though.

I have enough spare tubes for my preamp now as I have also stocked up on 5751s too. Now I gotta get a couple of nice sets of 12at7 for my amp and I should be set for tubes indefinitely.

Yes the Amperex's I have had the orange globes on them until I cleaned the pins with alcohol and now no more orange globes unfortunately. But I know what they are....

My preamp takes four 5751s and two 12ax7 but I dont think I can replace the 12ax7 with 5751s there because they are in the phono stage.
 
Hey pilotputz,I got a bunch of the old CHS 12ax7 blackplate sylvanias,all are used.Whatcha want to try?pm me.
 
Thanks seamas!
You rock!!

Hey, Kegger!
I've been on the lookout for some 5751s. I've heard good things about them and intend to pick some up next time I cross paths with a good deal! Thanks for your input.
 
The 5751 is the close tolerance version of the 12AX7?? As I recall I installed the 5751's about 15 years ago when I retubed my preamp section.
 
I was of the belief that the 5751 was a low noise, more rugged, military version of the 12ax7. I believe that 5751 is slightly lower gain as well: 80 to 12ax7's 100. I believe that's why it tends to not work as well in the phono section of the preamp. I could be wrong, though. I don't really have much experience with the 5751.
 
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