12AX7 so many choices, how to pick?

[alerich]

Ed's point of real NOS tubes has me wondering.
This supply must be very limited and trending toward extinction every day.
It makes me wonder how man of the tubes sold as NOS actually are unused tubes?

In addition, most of the really good ones have been culled out over the years/decades. Every single tube that RCA or GE or Mullard made back in the vacuum tube heyday wasn't a winner. Some were noisy. Some were microphonic. Just like what we see today. Overall the quality was higher and there were likely fewer duds but there were still duds. Most of the really good ones have been sorted through. What is being hustled today is the best of the rest or sometimes not even the best of the rest. There's a lot of glass being sold simply based on the ink print or etching it has on it. Once in a while someone unearths a case of pristine unused tubes but expect to pay a car payment for them.

Case in point: I have a really nice Westinghouse branded 12AX7 that I love. Sounds great in V1 or every amp I put it in. It's a pre-war EI tube made on the old Telefunken tooling. It's basically an old Telefunken clone. Great tube. It is currently making my Soldano sing. I saw one recently online from a NOS tube dealer. $35. Not gonna break the bank so I rolled the dice since I love the one I currently have. It's an exact copy of my current tube and it is microphonic in every amp I have tried it in. It might be useful in my PRRI. I haven't tried it there yet.

Buying old tubes is a crap shoot, at best. It can be fun and rewarding but understand the risks going in and remember the old adage "If it sounds too good to be true...".

[Ed_Chambley]

Oy yoy you Ed you sure do take this seriously
We are talking about electrical components  here aren't we??
Or are we talking religion and politics??
Seriously
No-one was calling you dumb
if I had a proper shiny , just came from a vault tube , the only reason i wouldn't trade it to you is that some 'enthusiast' would pay me piles for it and then i would go buy some other perfectly useful new tubes or other things like guitars strings, food etc etc
Anyway clearly this is really important to you and I apologize if I'm making light of it
However I never think it's bad to be silly
There is enough unhappiness in the world from people taking things excessively seriously. we are witnessing it all the time, sadly


I don't want any part of this 'debate ' I was offering the original fellow an opinion and I think a reasonably sensible one
To concentrate on building and amp and not worry to much about hunting down special important parts which will make tiny differences


To me the magic is in the player, the mind the heart the soul and the music not in the glass tubes
time spent tube rolling could be better spent playing and or rehearsing
I'm sorry I'm not preaching to the prevalent choir with this concept


I had an opinion and Jojokeo told me I was deaf, I had old strings, I had crappy amps etc etc etc yeesh!


I responded with humour as I was trying not to be offended by the rudeness


I am not stopping anyone from spending any amount of time with capacitors and tubes etc
I just prefer playing music , and making amps for fun

The OP, remember him?  He asked if there are any benefits to a particular 12Ax7?  This thread has 50 posts of which 15 are yours.  Your first opinion was acknowledged and anyone with comprehension skills can certainly understand your position.
Do you take your investments seriously?  See you overlooked one huge benefit in having a nice supply of New Old Stock tubes.

Care to even guess how much percentage gain you would have made in an investment of having held NOS tubes for even 3 years?  How about the 48 matched Mullard XF2's I got in the late 80's when my friend closed his electronic shop?  Just the increasing value alone makes the NOS the better choice.  The reason is they are not making them anymore.
Also that old tired comment that tone comes from the hands and _______________ (insert great player here) would sound the same no matter what he is playing and that is simply not true.

Would Chet Adkins sound like Chet if he were using Eddie's tone on Eruption?  Would Stanley Jordan sound like Stanley if he played a flat top with no distortion/overdrive.  Of course not because he relies on the high gain to make all his taps ring out.  Joe Banamassa is quoted as saying if it were not for the tones he gets from his amps and electric guitar he would probably not even play guitar.

You are right, we are talking about electronic components and not religion, but most of us are here because somewhere along the way we experienced the joy of the tone of a simple tube amp and guitar.  This impact to a lot of us could be compared to religion as in the area of life changing experiences.  You do not have to imagine the impact equipment like a Marshall, Fender and Vox made.  Simply listen to music recorded prior to the birth of Rock and Roll which would have never existed if it were not for this unnecessary stuff like tube amps.  I mean Robin Trower could have recorded the Bridge of Sighs album using a Martin D28 and it would have sounded just like it does.  The tone is in the hands.

Ridiculous comment?  I think it is no more ridiculous as saying tone comes from the hands.  A players style comes from the hands and the Tone-Pitch-Timbre comes from the instrument.  In our case vibrating strings.

Another thing about tubes.  They are not very efficient and will never produce the cleanest tone compared to other methods of amplification.  Tube amps take more maintenance and simply cost more and are not as reliable as other amps and are much more difficult to get high wattage from.

I have read a lot of your posts where you go to great measures to get a clean tone and use very expensive old speakers like JBL and you know there is really no difference between a JBL and a UTAH since all you have to do is practice until you can get the tone in your hands to make any piece of gear to sound like you want.

Am I serious about this stuff?  Probably not as much as you may be thinking.  I just simply do not agree with your first reply or the other 14 needed to expand and or explain your position.  I did not call you, you called me out.  Now that you have I feel obliged to explain other areas where I do not agree.

Now I am putting these things because I mean nothing offensive to you and that I am not being serious.

And one more for Jimbob

[jojokeo]

There's a lot of glass being sold simply based on the ink print or etching it has on it. Once in a while someone unearths a case of pristine unused tubes but expect to pay a car payment for them.

This is true for the less informed and the true collector. The better the print, clarity, clean shiny pins, and special markings <>, date codes, etc. will fetch nice prices now and even greater in the future as Ed mentioned. Especially even when taken from a pristine box or sleeve of boxes where it's fairly obvious these may have been stashed away in someone's shop or home maybe an estate sale? If you are diligent, tenacious, & lucky enough every once in a while you stumble onto something very worthwhile and get rewarded for your efforts.
 
Now as simply a guitar player that appreciates the finer aspects of our crafts, if you know about tube construction you don't need any printing or box to tell you what you are looking at. Like that Westinghouse of yours, this wasn't made by Westinghouse as I'm sure you know? But you know the instant of plugging that bad boy in and warming it up when you strike your first chords and hear pristine tonal bliss, the degree of headroom you like, the tight punchiness and body, the 3D sound quality permeating your senses...whatever qualities you value - you have a winner. It doesn't matter if you searched far & wide through a tube dealer or it came as a part from an old organ amplifier that was being thrown away in a junkyard near you...you have the sound, tone, and amplifier of your dreams. What did it actually cost you? And even better, did you create this for yourself? What is this all worth to you?

[jojokeo]

This is for anyone and everyone but no one in particular:
this is a "tube" amp forum. To dismiss and/or poopoo the very crucial, critical, and important role of the tubes themselves which over and over again are so carefully biased and provided carefully filtered voltages to doesn't make any logical sense whatsoever and is entirely ignorant to this fact at best.

[Ritchie200]

Bias?  So that's what happened....

Jim

[jojokeo]

Brah, you shred so hard you melt yo' glass! 

[Ed_Chambley]

Bias?  So that's what happened....

Jim

Great Playing causes that!!!!!

I thought you would know that.  Seriously, I would guess flyback since those burning things are Majors.

[Paul1453]

So from my extremely limited group of test subjects.  Basically 1 of each kind.

I would rank my premium 12AX7s as follows:

1.  Mullard
2.  Bugleboy
3.  Other Old Stock

Would any of you other premium tubers care to give your brand ranking preferences?

[HotBluePlates]

Don't have a ranking preference; sometimes different 12AX7's sound different, which then makes one good for some applications and not others.

I really like the neutral, balanced sound of Telefunkens. But then the warm sound of some RCA's is sometimes the way to go, while other times the lively top of Mullard or Amperex is the ticket...

[Willabe]

There is a good article series on Capacitor Sound printed in Electronics World in 2002. I submit it is scientific, having been researched and written by a capacitor engineer and because it gives results that, while substantiating some of the general claims about cap sound, also points out notable deviations (like how different flavors of ceramic dielectric caps both represent the worst- and best-measuring samples). The author spends a great deal of space on his measurement setup to enable others to duplicate his results; result replication is important for published scientific research.

(A quick note: "PET" in the articles is polyethylene theraphthalate, also known as polyester. But there's more than one type of polyester, and Mylar is a special form of polyester. "PP" generally means polypropylene in the article. For all dielectrics, construction methods can differ, and the article suggests construction method can cause measurable distortion in some caps.)

I read through this and I get some of it but.......  care to boil it down a little? 

[Ritchie200]

Don't have a ranking preference; sometimes different 12AX7's sound different, which then makes one good for some applications and not others.

I really like the neutral, balanced sound of Telefunkens. But then the warm sound of some RCA's is sometimes the way to go, while other ties the lively top of Mullard or Amperex is the ticket...

+1

Jim

[HotBluePlates]

..  care to boil it down a little? 

If a cap was an ideal device and introduced zero distortion, it would have no "sound" and all caps with identical ratings would be interchangeable.

Except that almost all caps measured had at least some distortion, which seemed to follow these rules:

• The bigger the cap, the less distortion (relates to different dielectrics and construction styles), except
• Sometimes caps of a specific dielectric distort much more/less than other of the same dielectric (ceramic was notable when 2 different types exhibited the most, and almost the least, distortion of all caps tested)
• Bias (voltage) across the cap increases its measured distortion (which is bad because we use caps specifically in places where there will be d.c. across them)
• Higher voltage caps seem to exhibit less distortion than lower voltage caps of the same type (which also amounts to them being bigger), and
• The rules don't always hold up (and there are bad apples even among normally-good types) so you should measure the specific caps you want to use to see how they really perform.

So if you hear a sound change when swapping caps, you're really hearing the difference in the artifacts each cap overlays on the intended signal.

[jojokeo]

Great breakdown of the info HBP. Thank you.
But (sorry can't read it now) does it mention anything regarding caps "breaking in" or becoming accustomed to certain voltages being placed on them to where the dielectrics sort of "form" or "settle-in" similar to e-lytics?
2nd - Does it mention anything regarding outside foil direction/placement and the related characteristics or phenomena this may have?

[Paul1453]

Don't have a ranking preference; sometimes different 12AX7's sound different, which then makes one good for some applications and not others.

I really like the neutral, balanced sound of Telefunkens. But then the warm sound of some RCA's is sometimes the way to go, while other times the lively top of Mullard or Amperex is the ticket...

Unfortunately, I haven't scored a Telefunken 12AX7 yet.
I do have a junk Telefunken R-R with a 12AX7 in it on my watch list.
I didn't want to pay the $75+ for it.

My Hammond/Mullard junk gear came in today.
I'll have to check out both of these tubes tonight.
That will bring my Mullard 12AX7 inventory up to 2.   

I do like the sound of these, not quite as bright as my Bugleboy.
Very full and warm sounding to my ears.

[Willabe]

Guys, so as to not hi-jack this thread I started a new thread, link below, on capacitors; 

http://el34world.com/Forum/index.php?topic=19534.0

[John]

I had  matched pair of Bugleboy 12ax/12au7 from one of my carcasses.


I loved the sound of my paypal account filling up. 


I know what Jojo means about tubes though. I like the way 6SL7s sound as opposed to the 12ax7s. It's hard to define, but I'd say smoother, warmer, and the distortion created is even softer sounding. Which, is not what everyone might want depending on what they play.


I had bought some Russians, and they sounded really nice. Bought some more and they are almost all microphonic, and don't have the same sweetness. Bought a bunch of NOS and used from a feller, and they are awesome. Frankly, I doubt if it would show up as a huge difference on a 'scope (and I wouldn't know what I was looking at anyway) . (except for the noisy ones)


I'm still not paying $50/tube. *squeaksqueak*

[Paul1453]

I had  matched pair of Bugleboy 12ax/12au7 from one of my carcasses.
I loved the sound of my paypal account filling up. 

I'm still not paying $50/tube. *squeaksqueak*

So you sold the Boys?  I don't resell any of my premium tubes.

$50 ??? many places are asking $150 for NOS Mullard/Bugleboys.

Makes me think of a Cash song.  "How highs the water Mama?  It's five feet high and rising".

I'm thinking that if I don't keep all my premium tubes, the others will all get washed away and I'll never have any.

[John]

I sure did sell 'em. I drove open tractor for many years and was too young to think about ear plugs. While my hearing is still very good, I can't tell the diff between "premium" and not.  I don't hear like EJ and don't play like him either. 

[Paul1453]

Opened my Hammond package on my dinner break.  Got a Hammond/Mullard 12AU7 but the tube in the 12AX7 spot turned out to be a Hammond 7247.

I was disappointed not to get another Mullard 12AX7, but I guess that 7247 tube is not all bad.

1/2 AU7 1/2 AX7 might still be useable in some guitar amp applications.   

Both made in the Mullard factory in Great Brittan, so I'm hoping they are quality tubes.

I saw listings for more than I paid total for just the Hammond/Mullard 12AU7.  I didn't even consider the other parts inside of the chassis. 
A quick peek inside revealed some kind of reverb/percussion do-dad.
Almost like some kind of side by side coils/relays about the size of some swiss cake rolls.   

[Willabe]

I was disappointed not to get another Mullard 12AX7, but I guess that 7247 tube is not all bad.
1/2 AU7 1/2 AX7 might still be useable in some guitar amp applications.   

No it's not bad at all.

That tube is some what rare, Ampeg among others used them.

[HotBluePlates]

Great breakdown of the info HBP. Thank you.
But (sorry can't read it now) does it mention anything regarding caps "breaking in" or becoming accustomed to certain voltages being placed on them to where the dielectrics sort of "form" or "settle-in" similar to e-lytics?
2nd - Does it mention anything regarding outside foil direction/placement and the related characteristics or phenomena this may have?

The article says nothing about break-in time for any tests that I recall. It also says nothing about outer foil connection.

It's therefore unclear if the measured distortion increase (THD and/or IM distortion) with a bias voltage added is something that would settle down after a period of time to allow the dielectric to absorb all it can/will.

Unfortunately, I haven't scored a Telefunken 12AX7 yet.

I was lucky: the first good tube amp I had (a '67 Princeton Reverb) had all Telefunken preamp tubes in it when I got it. I played exactly 1 chord on that amp and knew it was massively better than the Peavey amp I had at the time.

Then I was lucky again years after: I bought 20 Telefunken ECC83's for $1 each at a hardware store in Nashville. 

[Ed_Chambley]

7247=12dw7.  Dual triode with a gain factor of 100 on the anode number 2 side and gain of 20 on anode number 1 side.  You do find them in Ampeg's, however they are really nice to cascode in V1.  It is similar to a cascode of a 12Ax7 to 12AU7.  Makes a very tuby sound similar to a Octal preamp tube.  Fat and warm.

[dude]

7247=12dw7.  Dual triode with a gain factor of 100 on the anode number 2 side and gain of 20 on anode number 1 side.  You do find them in Ampeg's, however they are really nice to cascode in V1.  It is similar to a cascode of a 12Ax7 to 12AU7.  Makes a very tuby sound similar to a Octal preamp tube.  Fat and warm.

Now that's something I never thought of doing, thanks I'll try that. I thought old Ampegs only used that tube....

But that first gain stage 12Ax7 is the most important preamp tube. You can get lucky sometimes buying on ebay used old tubes but it's a crap shoot. If someone is selling one most likely the tube is beat.

Hey, JoJo want to sell any of those old tubes, just kidding but nice collection. I love the Philips Holland made eL84s, in an 18 watt.

Bottom line: tubes matter to me, only I'm not picky on rectifiers as long as the voltage is what I want. 

K caps, plate resistors have a lot to do with tone but tone is subjective. One man's holy grail is another's  junk....   

Remember that first tube is the one to fool with as long as everything else is up to par...

PS: Don't get too sensitive, no thin skin allowed here

al
 

[sluckey]

I thought old Ampegs only used that tube

Magnatone is quite fond of that tube also. My M10A has one for the vibrato oscillator/driver. And Hammond really likes them. There are 3 in my AO-63.

[Paul1453]

You can get lucky sometimes buying on ebay used old tubes but it's a crap shoot. If someone is selling one most likely the tube is beat.

I love the Philips Holland made eL84s, in an 18 watt.

PS: Don't get too sensitive, no thin skin allowed here

al

Got the tube lot thing covered in my junk gear thread.  I have always had great luck buying the junk gear, those tubes have not been picked through.
I've got 1 Miniwatt and 1 Bugleboy EL84 made in Holland, that I want to team them up in an amp eventually.

[Ed_Chambley]

I thought old Ampegs only used that tube

Magnatone is quite fond of that tube also. My M10A has one for the vibrato oscillator/driver. And Hammond really likes them. There are 3 in my AO-63.

Sluckey, have you ever considered trying one in the AC15 Tremolo/Vibrato.  I do not come close to understand the Vibrato circuit, but I think the AU side would then drive the tremolo and the AX side would drive the Vibrato.

Just wondering if the Vibrato would get stronger?

Now don't jump on me, I said I did not understand the Vibrato.

[Ed_Chambley]

7247=12dw7.  Dual triode with a gain factor of 100 on the anode number 2 side and gain of 20 on anode number 1 side.  You do find them in Ampeg's, however they are really nice to cascode in V1.  It is similar to a cascode of a 12Ax7 to 12AU7.  Makes a very tuby sound similar to a Octal preamp tube.  Fat and warm.

Now that's something I never thought of doing, thanks I'll try that. I thought old Ampegs only used that tube....

But that first gain stage 12Ax7 is the most important preamp tube. You can get lucky sometimes buying on ebay used old tubes but it's a crap shoot. If someone is selling one most likely the tube is beat.

Hey, JoJo want to sell any of those old tubes, just kidding but nice collection. I love the Philips Holland made eL84s, in an 18 watt.

Bottom line: tubes matter to me, only I'm not picky on rectifiers as long as the voltage is what I want. 

K caps, plate resistors have a lot to do with tone but tone is subjective. One man's holy grail is another's  junk....   

Remember that first tube is the one to fool with as long as everything else is up to par...

PS: Don't get too sensitive, no thin skin allowed here

al

Yep Dude, it does work, but you still use a whole socket and you could use a pentode there.  That is what a lot of people do, but they are cheap even in NOS which does provide a very low microphonic 12Ax7 section.  I did one and made it switchable.  Waste of time cause I never switch it off.

I am adding a fun pot to the cathode of the lower gain side currently.  When I tested doing it I ended up with a range of resistance from about 500 ohms to 2k.  Doesn't sound very good at either end of travel, but it is still nice.  You can go from warm and fat to a nice light overdrive.

[sluckey]

Sluckey, have you ever considered trying one in the AC15 Tremolo/Vibrato.

Yes I have, but not while I was hot and heavy on building the AC15. Too late now, at least for me, for 2 reasons... You would have to switch triodes. The oscillator needs the AX7 side (pins 6, 7, 8) and the phase inverter needs the AU7 side (pins 1, 2, 3). So you would have to rewire the socket. Also, I have a bunch of AX7s. I have no spare DW7s.

[Willabe]

There's a new made DW7 that they make either way, AX7a/AU7b or AU7a/AX7b.