Why do old tubes sound better than current tubes?


just wondering, is there something in the design, materials, or fabrication that makes old tubes sound better than those being currently produced?

it seems nearly universally held that old tubes are superior sounding to those made today - is there something specific about the old tubes that make then sound better?

-Scott
128x128srosenberg
I have great things about the new gold lion 12ax7 also, I am going to try them soon.
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Orpheus, yes, what I am looking to establish is a feel for how widely Gm1 and Gm2 tend to differ from each other. And if any correlation can be established between the degree of that difference and whether the tube is current production vs. vintage, or among brands.

The 5963's I was referring to are RCA's date-coded 57-31 and 57-35, with long black ribbed plates and square getters. My tester indicates a nominal Gm for 12AU7's of 2200. The tubes in question typically measured about 2700 for one section and 2300 for the other, which means that one section was about 17% higher than the other.

In most cases the section having the grid on pin 2 was higher than the section having the grid on pin 7, but in one or two cases it was the opposite.

Regards,
-- Al
Almarg, a 5963 is equivilant to a 12au7. Would a pair of 12au7's Gm 1, 2800 Gm 2, 2850, NOS RCA Cleartop be in the ballpark of what you are referring to.
Kirk, thanks very much for your informative and characteristically knowledgeable post.

To complete the picture, can anyone cite significant measurement experience that would provide a feel for the degree of section imbalance that can be expected for various makes of vintage and current production dual triodes?

Thanks,
-- Al
Hi Al, it of course depends on how the tube is being used in the circuit. If the two sections are cascaded single-ended transconducance amplifiers, or a triode driving a split-load phase inverter, then I'd say the matching matters not at all, so long as each section of the tube is within specs to work for its own part of the circuit.

But for a differential amplifier or cathode-coupled ("long-tailed pair") phase splitter, then the matching of the two sections affects the production of even-ordered distortion products. Both of these types of circuits are sensitive to both quiescent and dynamic balance between the two active elements. The extent to which the circuit can tolerate an imbalance is generally directly linked to its transconductance -- the higher the transconductance, the more critical the balance. It's also wrapped up a bit in the tail current - a true current-source will make the balance less critical for large-signal distortion. One can also place degeneration resistors in the cathodes, and increase the tail current to keep the same transconductance . . . and make the balance less critical.
Orpheus10, yes Brent Jessee's article is certainly an interesting read. However, the concerns about genuineness and condition are not applicable to the 5963's I referred to.

The 5963's were part of a large collection of tubes I purchased about 20 years ago, from a very nice elderly gentleman in my local area, whose career had been servicing radios and tv's. All of the tubes had been stored for many years in his nicely appointed house, and he obviously had no interest in misrepresenting anything in order to maximize his profit. He sold me the entire collection of about 1400 tubes for a total of $65, and he obviously just wanted to get them out of his house and to have them find a good home. I am an antique radio collector, which is mainly why I purchased the collection (very few of the tubes he had are applicable to audio).

Brent's article also contained the statement that:
"Five percent is doing really good for a match of vintage NOS tubes. Most amplifiers that are designed correctly should be able to operate just fine with even a 25 percent or greater mismatch, provided the bias is set correctly.
Which provides an interesting quantitative perspective, but the reference to 25% is obviously addressing power tubes.

So my questions about section-matching of small-signal dual triodes remain.

Thanks,
-- Al
Almarg, if you will open NOS, on Mapmans post dated 08-23-10, and then read my post above his which was posted before his post; you will be able to reach some very interesting conclusions.
tung sol 12ax7 gold pins, very musical, sovtec lps 12x7 , very open great bass , but maybe a little less body than the tung sol.
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A question for the assembled experts here with respect to small signal dual triodes.

I'm wondering how significant a variable in all of this gain or gm mismatches between the two triode sections within a tube might be, and if that might account for some of the divergence of experiences with these kinds of tubes.

I recently had occasion to test about a half-dozen absolutely NOS 1950's RCA 5963's (12AU7 equivalents) on my Hickok 800A tester. All of the tubes measured well and matched each other just about perfectly. However, all of them had close to a 20% difference in gm between the two triode sections.

As someone with minimal tube-rolling experience, I'd be interested in comments on how common that kind of difference (or worse) tends to be on both vintage and current production tubes, and on how significant it might be for each of the kinds of circuit functions dual triodes are used for.

Re Grant's question, fwiw I'll mention that in my Paxthon VTA-160 I've just replaced a pair of 1960's vintage used Telefunken 12AX7's, which had measured well until one of them recently developed a problem, and a pair of the NOS 5963's, with matched and balanced pairs of Genalex Gold Lion reissue ECC82's and ECC83's. My early impressions of the new tubes are very favorable, with improved clarity on high volume peaks, and lower noise. (The power tubes I've been using all along are a matched octet of SED "Winged C" EL34's).

Thanks!

-- Al
Tvad, You are right. I did read too much into it I think.

New production (or recent productions) I have found a place for:

SED 6550, SED EL34, SED 6L6GC, and SED KT88's (I really like SED's)

Re-Issue Tung-sol 6550 (in one amp)

JJ and NOS Tesla 6922's and JJ and NOS Tesla 12AX & 12AU7's. I like the NOS tesla's better, but not that much and they are hard to get and can be spendy.

EH6922's (one application so far - not universal by a mile).

Re-Issue Mullard 12AX7's (one application so far)

EI 12AX7E (long grey plate) - my go to NP 12ax7 as a starting point/reference. I really like this particular EI though I guess it is out of production. I've had no QC problems with this one either.
EI 6DJ8 but it is not as quiet or rugged as I like. Again it is no longer in production.
EI 6CG7 - the only new one in production. So far so good but I'm just starting an inquiry into this tube type for a specific amp but so far so good.

And, FWIW, I've got a few others that are still trying to find a good home. Curiosity may have killed the cat - so far I'm only limping! :-)
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Tvad, Forgive me for not writing a book about my stuff and tube experience. No one would be interested, even you. Talk about a cost/benefit ratio! :-)

However if I see a post where I can knowledgably recommend a specific new production tube to get a specific result I will do so without regard to whether its old or new. And that is likely the only time I'll ever get into a discussion on the internet about what tubes I like (or not).

I was really doing nothing more than advocating that those who would come here seeking advise take less than very specific advise in response to very specific request with lots of cynicism. A poster should keep a mind open to all possibilities, including that in many applications new (or recent) production tubes can be, or are, as good as he needs in that specific application. IMHO, 'general' rules, broad observations, and general recommendations suck. Now for someone who can't do better than ask for 'What's Best' I'm sure that generic responses would be fine.

BTW, I realize that you have posted that you have not improved on NOS tubes in the applications you have changed tubes in. I take you at your word. But, consider for a moment that this statement really means little beyond the needs of your applications and the number of new (or recent production) tubes you tried as an alternative. Not so many I think IF you have been predisposed to a conclusion based on the age/expense/rarity/ of the tube or the hyper critical application you were using when you reached your conclusion.

Ciao

I still think nostalgia is part of it.

Old tube gear had a certain sound different than modern gear. part of it was the tubes perhaps but also the overall state of eletronics design 50 years ago compared to now.

Old tubes in good condition still perhaps deliver that sound compared to more modern high end sounds.

The old tubes perhaps are more in the rhythm and smoothness camp and the newer ones more in the detail and resolution camp?

I'm sure there are exceptions, but that is my theory. I have too little actual experience with a variety of tubes these days to say for sure.

Similar to old low res TV versus newer HD TVs. You can see more details in HD but not everything is more beautiful in HD necessarily!
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IMHO the blanket pronouncement "NOS tubes always sound better than new production" is the mantra of salesmen and the deaf. That they can be, for sure. But as often only have that potential if they actually are any good, as in not used up and/or noisy.

More importantly it is ALL about utilization and tone. Their use is not needed if they don't actually improve anything or give you the tone you're looking for.

FWIW, I use a lot of tubes and I get good mileage out of new production tubes as well as NOS and often actually prefer them, especially on a cost/benefit ratio.

FWIW
I suspect that the aging process may have something to do with this. I have a number of very old globe tubes along with the newer equivalents with ST shape bottles. I consistently have found that the old globe tubes sound better. I doubt that the bottle shape makes a difference and I would be think that quality and manufacturing expertise would have been higher when the ST shape tubes were made (50-60's vs 30-40's).

In particular I have a set of blue glass Acurus 27's that were made prior to 1931. They sound notably better than the later 50's version.
"some old tubes sound great, some sound like crap, some new tubes sound great, some like crap"

I suspect this to be true.
some old tubes sound great, some sound like crap, some new tubes sound great, some like crap. Sorry ,but the notion that anything nos is better than anything new is just not true. I listen to the sound, not somebody's marketing hype.
I claim to have golden ears in regard to NOS tubes. I bought some bargain NOS tubes that sounded half as good as full price tubes and I sent them back for full price tubes. MY point is, leave bargains for the bottom feeders.
I have bought tubes from "Brent Jesse" for years. A reputable dealer makes his living dealing with "golden ears", he can not afford not to deliver the goods. Since there is absolutely no way to tell an OK tube from the real deal by looking at it, and only if you got the ears can you tell by listining to it; your best option is to only deal with a reputable dealer.
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BLindjim,

Never thought about it but you are right. New old stock sounds like marketing jibberish. Its old, oh but its new! Oh sorry but I meant unused, not new. How do I know it was never used? Well, it reads like new. Yeah right! Funny.

I agree tube rolling can yield benefits, but the book is still open for me on the merit of NOS versus otherwise. I may never know though because so far for me, the fewer tubes, the better. And I like the few that I already have!

I think the very lable of 'NOS' is misleading.

Unless my parents or some other close relative bought some of these claimed "NOS" tubes when they were young and can now recall it vividly, and kept them in a box clean and dry for the past several decades.... well those tubes I'd call NOS. Otherwise, NOS means very litttle to me apart from that they are old... New? Maybe new to me... but NEW outright?

I'm going to be quite doubtful. But if my gear and my ears say they're a step up... I'm good with that, and that means only they measure out well according to orig specs... but certifiablly 100% virgin new? Probably not. not IMHO.
Tube are often represented as NOS that are probably old pulls, and often include testing results that turn out to be either false or based on poorly calibrated testers. Most tube testers do not subject the tubes to full power tests (the Amplitrex does do this) or give actual numbers for transconductance and other measurements, so it is hard to get meaningful readings in terms of how much life is left in the tubes.

I don't know to what extent older tubes decline without use, but, I have some old tubes that DO test very strong on my Amplitrex so I know that at least some tubes do not deteriorate with age.

As to whether NOS tubes are overpriced, that really is a value judgment. It is entirely up to each person to determine whether it is worth the cost to conduct the search for better tubes. In every instance where I, or my friends, have tried different tubes, we have found alternatives to what the manufacturer supplied that sounded better. That was the case with my amplifiers, and my amplifiers came from the manufacturer with old tubes (RCA bi-plate 2a3s, red-base 5692s). In my phonostage, I really like the result of using old Telefunken ECC803S tubes. I know that they are now unbelievably expensive; if anyone knows of alternatives that sound like that tube and cost less, please provide such information.

Manufacturers of tube gear almost always use current production tubes because availability and consistency are of prime importance. Since alternative voicing is really a matter of system matching and personal taste, it makes less sense to use much more expensive older tubes when the result (matching customer's needs) is entirely unpredictable. Thus, in almost every case, their is at least THE OPPORTUNITY to "improve" the result by selecting alternatives, whether other brands of new tubes or older tubes.

" I've bought tubes that are claimed to be NOS from supposedly reputable sellers that test pretty mediocre on a good, modern tube tester (Amplitrex)."

So are they real NOS tubes or not? PErhaps NOS tubes are just not always the cats meow? They are old after all. Most electronic devices decline with age.

"Also, there is such a wide variety of voicing of older tubes that it is easy to come up with simply wrong tubes for a particular application. "

I think one must be willing to experiment with lots of different tubes to find the best. Buying overpriced NOS tubes just because they are NOS will break the bank sooner and perhaps actually prevent one from finding the right tubes perhaps?

Does Flo Rida or the Black Eyed Peas sound better with NOS tubes?

"Nothing would make these guys sound good on anything other than an MP3 player, IMO. ;-)"

I use stock 12AX7 tubes in my ARC sp16 tube pre-amp and BEPs sound just they way they should to me and mega miles better, no comparison, than on an Ipod with earbuds which typically has very limited dynamics.
I've got some of those expensive, NOS EL 34s. Maybe I should auction them off since I replaced them with current production 6AC7 because they sound much better to me in my amp. I like syrup on my waffles, but not my music. ;-)

My amp, pre and phonostage are the same as Doug's. So, ditto what he said.

Does Flo Rida or the Black Eyed Peas sound better with NOS tubes?

Nothing would make these guys sound good on anything other than an MP3 player, IMO. ;-)
Certainly, particular designs, system synergy and personal taste could favor any one particular tube over another. For small signal tubes, I have generally found that older production tubes sound better, and also last much longer.

The big problem with older tubes is that one hardly finds truly new, or barely used, old tubes on the market these days. I've bought tubes that are claimed to be NOS from supposedly reputable sellers that test pretty mediocre on a good, modern tube tester (Amplitrex). Also, there is such a wide variety of voicing of older tubes that it is easy to come up with simply wrong tubes for a particular application.

In everything that I've heard, for my taste anyway, I've been able to find alternatives to the manufacture chosen tubes that I prefer. Almost always that alternative has been older varieties for small signal tubes. But, then again there are a LOT more older choices.

I own modern 2a3 power tubes that do sound VERY good (EML meshplates and solid plates) so I can say that there is good current production of those tubes. A friend has AVVT 300bs that are quite good and distinctive (not as mushy on the bottom as most 300bs, new or old).
Viridian, Opheus10, Tjnif, others...

Regarding some of the more commonly used preamp tubes, do you find that "joe's tube lore" remains a valid tool for winnowing/choosing vintage pulls etc when preparing to do tube rolling?

Jim
I have a rather LARGE collection of NOS and "pulled" tubes both preamp and power tubes bought most in the 90's. I 100% agree w/ orpheus & Virdian. I originally collected vintage guitar amps from the 60's (mostly Marshalls) before I got into i-Fi again. In my experience ANY new tube does NOT compare w/ vintage tubes,period! Now I'm just talking preamp tubes. I will attest to the fact that when it comes to KT88 and Kt66 tubes some of the new ones beat out my vintage ones. I must stress that I'm comparing them to vintage USED.
When it comes to NOS and even used 6L6's/5881's, El 84's, and EL 34's..... NO COMPARISON! the vintage win! Especially true w/ EL 34 mullards and telefunkens. I would not even "think" to put in ANY of the new variants available when it comes to them. My 02 cents...
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Viridian, we found something we can agree on; I think. New tubes do not even compare to NOS tubes. NOS tubes can take gear to another level. Let me be specific; I am referring to preamp tubes, those are the one's I have had experience with.
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Vacuum tubes require, as should be obvious in their name, vacuum. Over the years, vacuum tube manufacturers and suppliers have turned to lower quality vacuum to cut costs. The high-quality vacuum supply is harder and more expensive to acquire.

As vacuum was mined, the easily reached sources of good quality vacuum (near the surface) were quickly exhausted leaving only more expensive and dangerous mining operations as the only source. As a result of several large and devastating mine implosions the larger vacuum mines that produced good quality vacuum were closed leaving only small boutique vacuum mines to supply the vacuum. Often, this vacuum contains impurities that must be removed (by what else than a vacuum cleaner!).

In the mid-80s, the Russian Kamakiskorvitchski brothers (Kamis for short) had a corner on the vacuum market. They had several tanker cars on a railroad siding in Siberia that contained most of the high-quality liquified vacuum available at the time. They carefully supplied only the Soviet and Eastern Block tube manufacturers with the high quality vacuum. Some smaller tube manufacturers were forced to use counterfeit vacuum containing large amounts of impurities. Again this vacuum needed cleaning.

Unfortunately, the supply of good quality vacuum has dried up in recent years. Only the older tubes still used high quality vacuum in their manufacture, but some tubes of the same era used counterfeit vacuum.

So one must be careful. Check your tubes and don't forget to use your vacuum cleaner.
When folks are making $$$$ finding pulled tubes from old TV shops and where ever they of course will say the best. I heard several new tubes that sounded better, some of the NOS tubes can have a warmth to them, but dynamics just are not there or tight bass, also the NSO can go to the other side and side bright and lacking mid-bass/bass.

In the end it is system depended and what you enjoy. I just ordered a set of the ECC83 Gold Lion reissues and I am looking forward to seeing what is what with them.

Will newer tubes last as long as Tele's who knows, but if they sound better who cares, just stock up on them. My friends had his stock McIntosh tubes in his preamp for several years and he says still going strong.

So myth vs. fact. Like LP's always sounding good, just not true.
Hi all, I do believe that the overall voicing of the system or the component and related things (cables, cartridges, etc.), all help set the stage for what tube or tubes will sound better. In my current system with my new phono stage, Fosgate Signature and Lyra Lydian Beta cartridge, I've found that two JJ Gold Pin 6922 tubes, sound wonderful. I am also using a mix of one JJ Gold Pin 12AX7 (ECC803 S) followed by one electro-harmonix 12AX7 Gold pin, then one NOS Mullard CV4024 (12AT7),and finally one electro-harmonix 12AT7. I love what I hear.

I tried using NOS Sylvania 6922 and NOS Sylvania 12AX7 as well as Mullard 12AX7 remakes, Sovtek 12AX7LPS, and of course the tubes supplied with the unit, all were less than desirable or even awful. For what it's worth I have discovered that with phono stage tubes it's worth paying extra for low noise and microphonics. So at least with this application it seems that for the most part, current production tubes out perform NOS tubes.
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because the people who sell nos tubes cant make money on new tubes. I have rogue m180s and have tried mullards, telefunkens, mazdas, GEs , rca cleartops, 5751 triple micas, and about five or ten I cant remember, sorry folks but the cheap as dirt sovtek 12ax7 lps is a winner, and so is the new tung sol gold pins, those are what I go back to again and again. the old tubes can sound nice and pleasant, but just dont have the resolution of the new ones, at least in my system. but now I cant brag and say I have three hundred dollar telefunkens in my amps either. I guess I will just have to listen to music instead.
One of the Chinese tubes, the Suguang 12AX7 is as good as NOS or better than other new for sure. I swapped some out and quickly swapped them back in.
There is much more to say about tubes than would fit into a thread. As was mentioned before, some tubes of days long gone by do have a unique mixture of materials in a pureness you won't find anymore today.
But in Audio it all comes down to the individual judgement of the respective listener/owner about what set of tubes he/she like BEST in a specific piece of equipment under certain circumstances ( circuit, matching with other components etc.).
There is no rule - there is no universal guideline. I for one do look for very specific mechanical criteria in tubes (and tube-types..) I use in amplifiers, because I know about certain direct links between sonic performance in a given circuit and specific mechanical/architectural circumstances in a tube. And this too is depending whether I use them as plate-follower, in SRPP mode, input-, driver- and/or phonostage-tube.
In the very end it always come down to what YOU do like best.
That is all that counts.
There is no BEST tube (type or version) out there.
There is a selection of great tubes for each specific purpose.
NOS or NNS - you will find good and great tubes in both camps (but you are likely to find a wider selection in the NOS-camp .... ;-) ..... ).
Try and enjoy.
I picked up a few of the new Genalex 12AX7GENGP tubes from NS and did an audition over a weekend between them and the 04/60's Telefunken I was using in my C500T.

Guess what -- even though still early, and the Genalex have only 5 hours on them or so since the swap out -- I like what I'm hearing & so, they remain in the MC slots.

Impressive so far folks.

Bob