Sucked Back Into Tube Rolling - Anyone Else?

renderit said:

I have been collecting NOS tubes for quite a while.
I have spent some money in the 'nuclear' options area.
The old military GE, RCA, Mullard and Raytheon are my primaries.
And quite a few "off branded" tubes because of it which were supposedly put out by the biggies but branded for consumer use?
Now I am playing with some cheaper NOS tubes that need adapters to work in the areas I need them.
I am finding some real surprises there.
I have been very happy with how they sound.
But I will admit that some new ones are not bad at all.

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Which new production's in particular Ren?

corpse said:

Finding old tubes is my alter egos mission. The only way is by word of mouth or scouring musty junk shops. Given the hours I have spent it is largely a worthless endevour. I have had a couple good scores. But really a waste of time.
That said old ones are the best. I would really like to get hard results on investigations of new production tubes and exactly which slots I should be putting my NOS glass in.

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Those amps you have deserve old glass in all their holes, half measures avail us nothing......

J.D. said:

Didn't a lot of those tube operations (including equipment) move to far east countries as tube production began to wind down?

Would be interesting to see if someone could revive those old machines and make exact replicas of the old tubes. I'm sure Reflektor and Shuguang have the ability.

Thanks for the tip on the RCA and GE tubes :hank

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From everything that I have read, it is not just about using the old machines and manufacturing gear but equally about (or more so?) the chemical engineering sciences. The "sonics and longevity" of the old tubes are related to the the metalurgy (metal element composition) and electron chemistry of the coatings applied to the cathode (ie...cathode chemistry). Of course I am certain the manufacturing gear and quality control of production play a big role as well.

One finding of newer production tubes is that their "specs" are reputed to vary quite a bit from each production run. In the old days the specs were very tight and pretty consistent. Randomly select most tubes from the batch and you could measure very similar electrical characteristics. It is suggested by many tube vendors that those specs are less consistent in newer tubes.

Having said that, I agree with the OP that I have indeed tried some new tubes from both Russia and China that can sound great. I am certain I would be using them if I did not have a room full of NOS tubes. I bought them from from old local TV /radio repair shops that were selling their stock in the 1980's for pennies on the dollar. They have moved with me over the decades from various residences. Needless to say I overbought! I did have the good fortune to test all of them on a tube tester back in the 1980's. At this point I will admit that as a young, regular gigging local musician, I way over purchased my tube supply all those decades ago.

Oh well, it is fun to roll tubes... Ren mentioned the Raytheon tubes. Another incredible sleeper brand! Original black plate Raytheon 12AX7 and 6V6 are peerless in a blackface Deluxe Reverb amp. Another killer combination are original Tung Sol 5881's and RCA 7025 in a Fender 6L6 spec amp.



Buck

Here's another old film...

I had seen that video before and was good to see again. Thanks for posting. We shall never see the likes of high quality vacuum tube manufacturing again...not like Mullard at Blackburn. The few dozen old 12AX7 Mullards I have, 161 and 163 production codes, all sound fantastic. They generally sound just slightly darker than most of their USA made counterparts. And sometimes that can be good in certain Fender amps IMO. The Mullard rectifiers are peerless in my estimate, unless you really need sag, they just can't be beat for reliable service and longevity.

buckaroo said:

I had seen that video before and was good to see again. Thanks for posting. We shall never see the likes of high quality vacuum tube manufacturing again...not like Mullard at Blackburn. The few dozen old 12AX7 Mullards I have, 161 and 163 production codes, all sound fantastic. They generally sound just slightly darker than most of their USA made counterparts. And sometimes that can be good in certain Fender amps IMO. The Mullard rectifiers are peerless in my estimate, unless you really need sag, they just can't be beat for reliable service and longevity.

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My pleasure Buck.

You sure have some fine valves in your collection.

From memory the change codes I6 (code for ecc83) and the 1 & 3 denoting copper support posts? as opposed to the later nickel. Don't suppose you have any of the date codes to hand? We can have a little fun trying to decipher them.

It's been a while since I talked about the nitty gritty on these wonderful valves, forgive me if my memory has faded. My interest certainly hasn't. Thanks for starting the trip down memory lane JD.

:salude

You're very welcome. While at one time I did inadvertently have/buy what now would be considered higher quality and/or vintage tubes as I went through a Marshall amp phase, I never paid too much attention to a lot of the details. I guess I was more concerned with the stuff actually working than having the optimal tubes. I'm looking forward to learning a bit this go round.

ourmaninthenorth said:

From memory the change codes I6 (code for ecc83) and the 1 & 3 denoting copper support posts? as opposed to the later nickel. Don't suppose you have any of the date codes to hand? We can have a little fun trying to decipher them.

:salude

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My understanding is a bit rusty to immediate recall but here is what I think I remember regarding Mullard 12AX7:

The I61 is earlier production 1960's until about 1964, then starting about 1965 the code changes to I63. (Some refer to these as 161 and 163 by the way.)

All of my examples have what I think of as "shorter" plates and they have a halo getter. The Mullard short plates seam slightly taller than the USA short plates but no where near as tall as USA long plates. The Mullards I have all have a "B" in the etched code indicating they were made at the Blackburn factory.

I think of the various tube eras of production much like that of guitars and amps: time passes and things change. Certain eras and locations of manufacture can be associated with certain sonics...given a reliable specimen to evaluate. The sonics from any given era sound a bit different for each factory. It is the factory and era of production that are key to understanding sonics and absolutely not the brand inked on the tube.

I am certain others know way more than me so maybe they will chime in and contribute. I find tube sonics fascinating and I love to roll tubes to listen to the subtle differences. The only thing more fun is playing the guitar! I will say that generally I prefer the sound of USA made tubes except for the tubes made in the 1960's at the Heerlen Holland factory, often branded as Amperex. Those 12AX7s are my personal favorites in Fender amps.

Here is a Mullard info link. There are many online but this reads like what I remember and agrees with what you said regarding the copper grid supports. I have not studied these codes in detail in years. Just a reminder that metallurgy and cathode chemistry are so key to a tubes performance. Some suggest that new tube production metallurgy as akin to soup can metal. The engineering and quality control of the old days is something to cherish in my view.

And if new tubes sound good then what fools we old men have become...some will say

https://www.effectrode.com/news/tube-enthusaist-tube-codes/

Great reading and video, thanks for sharing.

I agree, for applications other than tube amps, those tubes likely were built to higher standards than current production which is mainly made for audiophiles.

I'm just glad that we tube amp guys have some options again for buying decent tubes at reasonable pricing.

One of my favourite amps of the last decade, a teeny tiny little thing, with the voice of an angel.

American built, British valves...for me a match made in that place.

I have it back with me for a while on loan, for an imminently incoming guitar; more to follow on that - to quote Mr Runyon, "A Story Goes With It"





Brimar 12ax7, Mullard EL33 (KT61), Brimar 6X5GT rectifier.




:biggrin:

Beautiful looking amp. What are those tubes?

buckaroo said:

Beautiful looking amp. What are those tubes?

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The bottom picture - a Brimar 12ax7, A Mullard EL33 (KT61) and an RCA 6AX5GT Rectifier.

The top picture (valves running) - as above but with a Brimar 6X5GT (EZ35) Rectifier.

Aesthetically it's a beautiful amp, sonically it's better. It's an Emery Sound MicroBaby.

http://www.emerysound.com/

:salude

How about the Tungsol EL-34's that Marshall has been using the past few years ?

Yep, saw those. Must be ok if Marshall is using them as OE.

If you want excessive details on the progression of original short plate Mullard 12AX7s, this was first posted by me on TGP awhile back:


"Mesa- Here's something still posted in this forum 2011 that might be of interest. Happy Thanksgiving to all-

Of Blackburn-made ("B"=coded) short plate 12ax7s, the sequence is as follows:

Initial appearance is 2/59, coded "I61". Note that long plate versions made at Blackburn coded "f92" continue simultaneously through at least 8/59, possibly even later that year.

These 1959 "I61" are distinctive in that they have:
four seams on top like the longplates;
silver colored grid rods (unlike the longplates and later I61);
top mica spacer with evenly-spaced "teeth" all the way around.

I am of the opinion (at least some of the time!) that first year production I61s from Blackburn tend to sound a little different than all other versions. But might be my imagination.

Starting around 10-11/59 and for at least 2-3 months transition period, the code remains "I61" but:
the grid rods go to bright copper;
mica changes to "skipped teeth" on top perpendicular to the plane of the plates (and ever after);
seams go from 4 to 2 on top.

I61s with "B" codes continue with above changes through 4/64; e.g., grid rods are copper, etc.

In 4/64 and 5/64, there are a few "I62"s that otherwise look the same, copper grid rods, etc. These are the only year/month codes I've seen for I62s from Blackburn (add: Thom pointed out one from first week of June). It's almost like "I62" was a mistake for these, or something changed rapidly.

Starting approximately 5/64 or so, code changes consistently to "I63" for Blackburn made 12AX7s. Grid rods remain copper.

In early '66, first few months, grid rods change to silver color not copper. Type code remains "I63", and remains "I63 for these waffle short plates from Blackburn through their entire run, i.e., until 1978 or so, possibly slightly later. Almost all although not nec 100% of these have 2 seams on top not 4.

You can note also that, until the late '60s, the halo getter ring was welded to a straight rod, i.e., the halo is perpendicular to the rod. By 1969, they were usually bending the rod, the halo was welded parallel to the bent top part of the "l-shaped" rod. This seemed to have started sporadically slightly earlier, but not before ca. '67. So if you have, say, "I63 B6E3" with silver grid rods, if the halo rod is straight invariably it will be 5/66 and if it is "L-shaped" invariably it will be 5/76.
Jeff W."

I patrol Craigslist regularly- I live near Atl and there is something almost daily to make me sit up. Yesterday it was a guy with a bunch of tubes. I have bought from him before years ago- everything tested strong.
$310 for the following- all are old pulls- prices are ea:
Telefunken diamond logo 12AX7 $50 (3)
RCA Black plate 12ax7 $45 (1)
RCA gray plate !2AX7 $25 (6)

I put a Raytheon 12ax7 into the V2 slot in my 62 VL and it certainly got more authority. I am going to try the TF's in my Marshall 2061RI. The prices appear fair.

Yes- and the VL also has new matched (32/33) VOS GE 6L6GC power tubes- that might help too.

I don’t ever remember not using NOS anything TBH, but in the spirit if this thread I bought some new 12ax7’s to see what’s up

Not bad at all actually. I went through the three positions on a JTM45 (with clear glass GEC’s). I tried the Mullard, Tung-Sol, and Svetlana re-issues. The main thing I noticed was they all sounded a bit more modern (a little more compressed and a little more gainy) than the NOS tubes - for many that migjt be a plus! For my taste though, I found the New Sensor version of the Svetlana the most “vintagey” tube. Less “gainy” and a bit more middy. I’d be totally happy with it if I ran out of my Mullards. I tried just using an NOS Mullard in V1 and the re-issue Mullards in V2 and V3 and it still resembled a more modern sound. I put the Svetlana in V3 (PI) and it was much better.