[Ericus Rex]

I don't want to start a debate on NOS vs. New Production.  In my book that debate is long since dead with NOS generally winning in both sonics and reliability (there are exceptions, let's not get bogged down with them in this thread please).  I would like to know why, in this modern age, can't we make tubes that are far better than NOS?

In this age of Ultra-Precision Manufacturing why can't a new production tube be guaranteed to last 10,000 or more hours so long as it's operated as intended?

Why do NOS tubes most often sound far better than their more recently produced brethren?  I've heard the rumours about EPA not allowing certain metals be used and dirty manufacturing practices now being banned but those arguments hold no water for me.  Nearly all new production tubes are produced in countries that either don't have environmental restrictions or completely disregard them (China, for instance).

So Roger, in your opinion, why are new production tubes so inferior (or spotty at best)?

[adydula]

Hi, I am not Roger....but have been around a looooooooonnnnnnngggggggggtime using tubes, building stuff, testing stuff with tubes etc..

We can build tubes as good as or better than anything else made in time period....and I for one think we actually still do. But this  usually starts the age old NOS vs New Tube battle discussions you want to avoid..

There is no real demand compared for them as there used to be except for us strange audiophile types....who think and belive things with valves in them are so much better or nicer sounding that other SS stuff.

I think that the boutique tube mfgrs would state and do state that what they make and sell for big bucks are as good or better than what we call NOS.

Lets see where this one goes....
Alex
 

[Ericus Rex]

Wouldn't it be lovely if tubes were manufactured with such precision that every single one produced was matched with every other one on the assembly line?  It seems to me that 'matching' is just the manufacturer putting tubes with 'like flaws' together.  Roger, am I just dreaming here?  If we can make nanobots and $50 smart phones why can't we make reasonably priced tubes with todays technology that leave NOS in the dust?  What am I missing?


Alex, the tube industry is not as small as you think.  Tubed guitar amps outnumber tubed stereo amps perhaps 300 to 1.  It's no coincidence that the vast majority of audio tubes are also in guitar amps.  And don't forget that the countries still manufacturing tubes still utilize tubes in their everyday lives far, far more than here in the US.  And if the tube manufacturers think they make a better tube now than ever why don't they last beyond 1-2k hours?

[milford3]

Who wants to start up a tube manufacture company?  Just need the capital for the start up.  We can make the best tubes on the planet.  Hum!

[bunky]

Some of the modern power tubes are really good.i dont play with too many of the newer small signal tubes because with a few rare exceptions the NOS sound better and last longer.the black treasure CV181-Z 6SN7 varient is a great sounding tube but i dont know if its a 10.000 hour tube  too early to tell.

[rpf]

Some of the modern power tubes are really good.i dont play with too many of the newer small signal tubes because with a few rare exceptions the NOS sound better and last longer.the black treasure CV181-Z 6SN7 varient is a great sounding tube but i dont know if its a 10.000 hour tube  too early to tell.

I agree that several of the new power tubes are quite good sounding but they seem to need to be changed by 2000 hours. I don't know how long NOS power tubes lasted but it would be nice if the new ones lasted longer. 

I also agree that most NOS signal tubes sound a lot better than new production - even  the expensive ones. With the caveat that although I've heard a lot of them, it's only been in several pieces of gear.

[Roger A. Modjeski]

As many of you know I work very closely with New Sensor, the owner of the Russian Reflector factory that appears to be the last man standing in Russia as Svetlana appears to be closed.

I buy tubes in large lots and every lot is different. Sometimes I return a whole lot and the next one and the next one. When I find a good one I try to buy a 3-5 year supply because I know there might not be another good one for a long time. Even then they sneak in some other problem. It's never the same. Furthermore, it appears that the tubes I return go to some other manufacturer who doesn't see what I saw. I know they don't junk them.

Like the statue we have of Justice, I tend to cast a blind eye to who made the tube. I just care how the tube tests and sounds. There are no good new production 12AX7s coming from anywhere. The Genelex ECC series is just horrible. My Hungarian NOS are sold out and my Yugo smooth plate are almost gone. I have some NOS Chinese production from 12 years ago that are excellent tubes. I hope people can get past their negativity of Chinese tubes. Chinese tubes got a bad reputation because they shipped a lot of duds. I have to discard 20-30% of what I get but what remains is very good.

I have been supplying output tubes for CAT amps for several years now. In this very nice, expensive amplifier I have been able to satisfy owners with Chinese KT-88s selected to Ken Stevens specifications. Although the Genelex KT-88s are fine tubes they will not meet his spec for grid leakage. So what makes a good tube.... One cannot shop by maker alone.

[medium jim]

Some of my Favorite 12AX7's are those older Chinese ones that have the double spacers with silver plates.  They measure around 1.1ma which is what they should....most New Production 12AX7's are usually around .9ma. 

I used to get my new tubes directly from Aspen Pittman, founder of Groove Tube, but he sold GT to Fender Musical Instrument Company several years back and I can no longer cherry pick.  Roger is correct that too much is made over where a tube is made, a good tube is a good tube. 

Jim

[Ericus Rex]

Thanks for your reply, Roger.

Why do you think it's so hard for New Sensor (and others) to make a consistently good and reliable tube?

[Roger A. Modjeski]

Thanks for your reply, Roger.

Why do you think it's so hard for New Sensor (and others) to make a consistently good and reliable tube?

In making tubes there are more chances to go wrong than right. There a lot of materials that can change from batch to batch. Wire gagues are not as precise as one might want, cathode coating consistancy is a big problem, having the micas really clean so they insulate well, getting the pins right (those vary a lot in diameter and the base of the tube is a purchased part).

When I visited the Sylvania plant in Altoona the man who have been running it for years told me they had 10 chemical engineers for every electrical engineer. Strange as it may seem, making tubes is very chemistry dependent. I was told that some years ago the Russians could not get cathode coating material from their usual domestic source. Getting it from the USA was too expensive so they got some from the Chinese. Turns out it wasn't so good for consistant emission.

I discovered this by checking emission and bias vs. filament voltage and found the tubes drifted all over the place and not together. Therefore pairs became rather unmatched as filament voltage varied even a little. I sent them all back. This is something we do at RAM TUBES that I can almost assure you no one else does. I personally do all the testing and because of my experience with tubes I catch these things that I presume others miss. I think a lot of what I send back ends up in some amplifier somewhere.

I recently looked at some other tube vendors who claim to sell very carefully and even custom matched tubes. They use the Amplitrex AT-1000 tester.  http://www.amplitrex.com/. This tester only tests one tube at a time. There is no way to equally warm and stabilize a test one at a time and get any reasonable number of them done in a day. Furthermore, it would be very difficult to vary filament voltage one tube at a time, record the data and compare it over a reasonable sample. You are not going to find out anything this way about the tubes you are dealing with today or the ones you get next month which will be different. 

In my experience current production tubes get most things right but there are characteristics that certainly vary batch to batch. I wrote an article on this year ago, here it is. It also gives some technical reasons why people do hear differences in tubes. I do agree with the reader who states "a good tube is a good tube" My job is to find them, test them and pick out the really good ones

http://www.tubeaudiostore.com/whyamsochwhy.html

[gsm18439]

The modern production Japanese Takatsuki 300b tubes are excellent. Expensive, but so are Western Electric.