Why aren't new vacuum tubes as good as old ones?

Jwm, I sort of agree although there are great sonic differences among the NOS also. I think either the skill of those who were making the NOS or the QC then with many tubes discarded.

Yes of course the RCA's sound different than the Sylvania's. I don't know why that should be the case since factories know the specs on how the tubes should be made. It may be slight differences in materials or tolerance in the parts.

I'm encouraged by the sonics of many current production tubes, especially some coming out of China. Many rank right up there with the legendary tubes, though more often than not, the old American and European variants still hold the edge in absolute terms. From my experience, I think it's in ruggedness that the old tubes hold a big advantage, particularly over many current production European tubes.

Shuguang tubes possess the best reliability in the industry reliability over the past decade. While the premium Chinese products get most of the attention, the run of the mill Shuguang 12AX7B, EL34B, KT88, and 5AR4 offer surprising sound on top of that reliability. Speaking of surprising, the dirt cheap NOS military Shuguang metal base 6SN7 (labeled 6N8P) will as well.

Personally, I find buying old used tubes that most pass over in favor of spending a lot more for NOS finds on sites like ebay to offer tremendous sonics, longevity, and overall value.

Lost art. That's why. New stuff can be very good, but will always be different. I wish some of these way-to-damn-rich philanthropists would occasionally pick a dying (beautiful) technology to keep alive (like vacuum tubes back in the 60's-70's) -- rather than the trendy shlock they typically flock to -- in order for future generations to rediscover some of the beauty and knowledge that has been created by our predecessors.

I'd love to if they made tubes that we use.

There is some subject dodging going on here...like regarding KT120 tubes. Do they have badly fired getters? Why do many feel they are great sounding, even compared to NOS whatever? Why have my 120s lasted 2 years of daily abuse and still show no signs of age? Do Psvane Treasures have badly fired getters? Why do the ones I use sound fabulous? Is New Sensor a factory full of worthless slackers pounding out junk? My re-issued New Sensor Mullards in my Class A guitar amp are perfect...why? Am I insane? I am? Oh...well...nevermind.

No Wolf. I think they sound good to you because of those bungee cords you connect everything with. And maybe you aren't completely insane it could be cabin fever with all that cold weather. Keep your chin up.

I feel better already.

Wolf, I know some of the techs at ARC. They use the KT-120s, but apparently really have to weed through them as many of them arc (no pun intended) prematurely.

However its a pretty neat tube- lotta power handling.

One way to look at it is they (Russia and China) don't take as much care, but there will still be tubes that hold up. We've seen some of our Russian power tubes (6AS7G) go for well over 20,000 hours. But that is by no means the norm...

I think they are taking greater care with the premium tubes we are seeing- like the Psvane, TJ Music and Sophia. Our customers have been giving use good feedback on those (which at this point has mostly been the 6SN7- which is our main signal-processing tube).

I had a sloppily made Psvane pair that I sent back, but that was cosmetic really (on one tube) and it was a matched pair...they did seem to sound OK. The next pair was better, and have remained in their sockets. I wonder what the number of bad 120s is relative to others at ARC, as there hasn't been much reporting of 120 failures otherwise, or at least from what I found in my research (research...ha...more like "lazily poking around").

Is it fact, or hype?

It's fype.

What is the definition of "good"? Sonic quality? Durability? Given the longevitiy of some tubes (300b comes to mind) and unless a tube fails "early," it will be hard to prove that new tubes are predictably shorter-lived compared to older ones. Or am I wrong?

Click HERE to view the Mullard video. This is really fascinating.....Worth a look.

quote]What is the definition of "good"? Sonic quality? Durability? Given the longevitiy of some tubes (300b comes to mind) and unless a tube fails "early," it will be hard to prove that new tubes are predictably shorter-lived compared to older ones. Or am I wrong?[/quote]

A 'good' tube sounds good and lasts a long time.

BTW, RCH Labs out of Carson City, NV appears no longer in business. 

Because the old craftsmen died 50 years ago.HELLO!!!!

☝🏻☝🏻 True enough. A lot of craftsmanship, old school tech, and perhaps now-banned materials are not available. 

I use some "vintage" tubes...I like chrome dome Sylvanias and Mullards that "flash." I don't know why manufacturers keep putting KT150s, KT120s, and Gold Lion KT88s in the amps they build...don't they know new tubes suck? They even fooled me into enjoying all of those and thinking they sounded great...some for years...

Current tube production is aimed at a small niche market.  Before transistors, tubes ran our electronic world.  They were critical and manufacturer's had to make quality product for the military, government and..  We are the hobby market and really don't amount to huge profits.

+1 for Sylvania Chrome domes , the Goldilocks of tubes , not too little, not too much .

How many tube guitar amps are out there? Small niche? I'd bet they're 90% of the tube market...gotta scratch that niche.

Yes but current tube production is not critical to the communications business, like in the past. Tube makers could do better but where is the motivation.  Product longevity does not keep the line moving.  

"gotta scratch that niche" ..nice
It seems as if more and more tube products are now out there compared to 15-20 years ago so,
while still not huge in the market I do think it is growing
.AND,
as Wolf_Garcia  stated
"how many tube guitar amps are out there?".
quite alot I'd imagine.
So maybe there would be some incentive to MFG some quality Tubes eventually.

Here is stuff I have that needs Tubes;
Stereo-
Schiit Audio Freya
Primaluna Prologue 5

Geetar Related-
Dr Z Rt 66 Head
Egnator Rebel 20 Head
Egnator Tweaker Head
Peavey JSX Mini Colossal  Combo
Peavey 6505 Piranha  Head
Gibson/Kalamazoo Model 1 Combo
JetCity JCA20 Combo Combo
Blackstar HT1 Head
Orange Micro Terror Head
Orange Micro Dark Terror Head
Vox AC4T1 head and combo
Epiphone Valve JR 5 watt head
VHT Special 6 head [2 of them]
Blackheart Handsome Devil 15 watt head
Blackheart Little Giant 5 watt head
Blackheart Killer Ant 1 watt heads[3 of those!,2 modified]


So,that's around 22 things around the house that use Tubes.
A few are only using tubes in the preamp section and
 all the others are all tube
so I am all for increased MFG of quality tubes

I suggest you try what Billy Gibbons allegedly did with a bunch of amps...his crew piled them up in a sort of large box configuration and stuck a mic in the middle of the heap...not sure how it sounded but hey, why not? 

like  Marty in Back to the Future with a bunch of amps instead of One Big One

Can anyone provide data or evidence for the claim that new tubes don't sound as good?

Data or evidence would mean things like tube characteristic curves showing that old tubes are closer to the ideal than new or double blind hearing tests showing that listeners can easily detect the difference.
 
Data and evidence would not include unsubstantiated statements like "in my opinion ABC NOS tubes are way better than XYZ new tubes".

jyprez,

You don't need the data, all you have to do is listen to NOS vs. New.

"new vacuum tubes are not as good as old ones "
That used to be my line of thinking. NOS tubes were made better, better choice of materials, more consistent, etc.

After trying the latest PSVANE Treasure series, not sure I would agree with that original line of thinking anymore.

The sonic qualities on the T-II PSVANEs are so good, I actually prefer them to many NOS types.

this would include input tubes as well as rectifiers. The VANE 5U4G, is an excellent sounding tube,....

Audio components that measure the best do not necessarily sound the best. There are many aspects of music reproduction that we haven’t figured out how to measure yet. Tests that objectively prove what we should like just don’t work in audio, it’s a very subjective pursuit. Can anyone prove that people should prefer Picasso over Van Gogh?

If one prefers current production tubes, that’s what he should buy and enjoy. If others prefer classic tubes that’s what they should buy and enjoy. That way everybody is happy.

So mr_m 
your answer is “no, I have no data or evidence” 

Agree tomcy6. Some people prefer components that distort more (measure poorer). I was defining better as “distort less”. 

My Yamamoto A08s uses 45 tubes.
I have both the original WW2 era NOS set, hand / ear picked and matched by Mr. Shigeki Yamamoto himself, and a set of new production EML mesh 45s.
The EMLs are 3 leagues above the NOS in terms of sound quality in every aspect.
Yes, they do cost > $700 for the pair, but they are worth every penny :-)

I have Mullard NOS tubes from England. These are FAR better than the newer tubes that came with my amp. Not even close....

.... b/c back in the 1940s to the 1980s, the quality of the tube was literally a Life/Death situation during the COLD WAR and all the millions of pieces of military gear from complex communication systems to airplanes (as noted, for MIGs to withstand the Atomic Cloud after an A-bomb goes off--> since the transistor designs could NOT withstand the Atomic Cloud and would fail ... mid flight in the MIG).

Note all the later model cars running around with burnt out lamps (not LED's, a different story altogether regarding solder joints and high temp LED's), and yet I bet there are 1958 Chevy's with original bulbs all around the car. I never replace the old copper bulbs in vintage units if they are still good, as they will outlast any new bulb.

I have heard some tube types say the "quality" of the parts/spotwelds and the purity of the vacuum itself is not a good as it was before Solid State. Could be the same with today's lame ass bulbs.

and alot of those people that made tubes back in the day have passed and the EPA aspect is more stringent in todays world.

Because old ones where made for war...new ones are made for audiophiles...although there are few new tubes that exceeds expectations...

Nobody knows why. If somebody did they would certainly be able to make exact duplicates. 

This thread is very timely.  I own an ARC Ref 150SE amp.  My amp uses 8 KT-150 tubes.  I either read or heard that KT-150 QC has dropped over the years.  I understand that ARC and some of the major tube retailers have a high KT-150 reject rate.

In any case, here's the bottom line.  I recently spoke with the ARC customer service rep.  He advised me that ARC is selling KT-150 tubes for $265 per tube.  ARC charges over $2650 for a complete retube of my amp (2 quads of KT-150 and 4 6H30s).  Yikes!! 

As an aside, several years I bought 2 quads of KT-150s from a well known and respected tube vendor.  The problem is that even though the tubes were matched, the bias settings between the set tube and slave tube were off by a lot.  By contrast, ARC tube match very close.

Any suggestions?