Why Can't Tubes Be Mass-Produced Cheaply?

I have a good many tubes in my collection, don't know the exact number but at least two or three hundred. Among these are many current production small signal tubes as well as NOS.

Among my NOS are Genelex KT77, KT66, Mullard EL34, Brimar 12AT7, Mullard M8162 gold pin, Mullard 6922 gold pin, 12AX7 Telefunken, Siemens and Mullard, 12AU7 Telefunken, 12AT7 Telefunken and 6DJ8 Telefunken. (Can you tell I'm a big fan of Tele's :^).

I mention this before stating my opinion that there are no small signal tubes being built today that are equal to the best NOS. This judgement is made based on critical tube positions and does not pertain to EVERY situation in every piece of equipment. Like other things in high end, the type and design of the equipment and associated system play a big role.

For power tubes, the quality of new production gets closer (perhaps as Dan_ed suggests), in particular Wing C in 6550 and KT88, Wing C EL34 and Tesla E34L come to mind as favorites of mine.

Granted Mullard EL34 XF1 and XF2 are better than Wing C and Tesla, but it matters most when comparison is made in a critical position such as power supply of Aesthetix Io or Callisto. In an amplifier circuit (Wolcotts come to mind immediately), the EL34 JJ Tesla is more an option than a requirement when compared to Mullard El34 as power tube. The difference is there, but sonics could be argued.

When comparing small signal tubes such as 12AX7, 12AT7 and (especially) 6922, the modern versions from Sovtek and others are nowhere close if the comparison is made in a critical position. By critical position, I'm referring to small signal tubes in EAR 834, Aesthetix Io and Callisto, Audio Research Ref 2, input circuit (12AT7) of VTL 450, 750 and 1250 to name but a few.

I admit the Russians have made huge strides in tube quality. The newest Sovtek 12AX7 varieties are much better than years ago and for the dollar are amazing. The problem comes when these tubes are required to be ultra linear, zero microphonics and totally free of noise. I personally know manufacturers that screen Sovtek tubes to find the best, and the report I hear is about 5% are usable in critical phono circuits. Worse, when a few of these tubes get a couple of hundred hours on them, they degrade to the point of being unusable.

Other new production tubes from Russia and elsewhere, especially the 6922 variety are dismal. I don't know of a current production 6DJ8, 6922 that's really good. As old stock there's Telefunken 6DJ8, Mullard 6DJ8, Mullard 6922, Amperex 6DJ8, Amperex 7308 (Military) and others.

Unfortunately most audiophiles have figured this out, meaning the price of this particular small signal tube has gone through the roof. A hand full of years ago I could buy Mullard 6922 for $15.00, today they can cost $100.00. It's not greed driving the price, it's supply and demand.

Well screened used or new stock old production tubes are often not only quieter, more musical and less microphonic, they last up to 15 or 20 thousand hours.

Money always comes into the discussion, so I would like to make a point. Back in 2004 I replaced my critical input tubes on my Aesthetix Io with the best grade Telefunken (12AX7) that could be had. Now, four years later my sound is equal to the day those were installed, no microphonics, no noise and wonderful sound.

To keep new stock tubes that quiet I would have gone through a lot of screening and replacement, meaning wasted time and still suffering less than best sound.

Quoting myself

Like other things in high end, the type and design of the equipment and associated system play a big role.

A short list of exceptions, where NOS tubes had little impact (as I recall).

Shandling CD player (rare Western Electric tubes no better than stock).
Atma-Sphere's older amps, 12AT7 position (Yugo worked as well as Tele).
Scott Nixon's DAC, Russian as good as premium NOS
Wolcott amps, 6GW8 position in input, stock as good as NOS
Tube Research OD4 position in circuit, little or no change among brands
VTL 750, 6350 tube difficult to get big upgrades with swaps.

Probably a dozen other tests that I've forgotten, but you get the idea, and why people disagree with value of upgrade. I would not be surprised if someone got different results than mine on this "exception" list.

The quality standards that Sugarbrie attributes to his Mom is exactly why tubes of that era were so special. The Germans, Dutch, British and Americans were all doing their absolute best to build the ultimate tubes that could be manufactured.

Back then tubes were necessary to the survival of all radio, TV, broadcast, civilian and military aircraft, as well as military communications, guidance systems, radar, computers and more.

Just think about it, tubes were even required for movie theatres, PA systems, TV broadcast stations, electronic organs for church, ham operators, test equipment and medical diagnostics.

Automobile radio's back then even required tubes, most 7-11 grocery and Radio Shack stores had a tube tester by the door and drawers of replacements for their customers. (Radio Shack even sold Telefunken, not kidding).

To make a point, look at the competition today between AMD, Intel, Texas Instruments and others that build high tech chips. It's a big business and quality, consistency, speed and dependability determines who wins and who looses.

That's the status tubes held during those times, equally important to consumers, big business and the military as high tech chips are today. Add in the fact that everyone took a lot of pride in workmanship and you have an era of very special circumstances that produced a product that will never be again.

Stevecham,

What I said in my post is:

When comparing small signal tubes such as 12AX7, 12AT7 and (especially) 6922, the modern versions from Sovtek and others are nowhere close if the comparison is made in a critical position.

By critical position, I'm referring to small signal tubes in EAR 834, Aesthetix Io and Callisto, Audio Research Ref 2, input circuit (12AT7) of VTL 450, 750 and 1250 to name but a few.

If you doubt me, do an experiment by putting new production tubes in the first stage of an Aesthetix Io and to make things fun, go with a .2 MV cartridge such as a Koetsu Jade.

If you can get new production tube to work as well as Telefunken, you need to reveal your magical source. I have a lot of people, including several manufacturers that would like to buy some of these tubes.

So are companies like ARC, Conrad-Johnson, and others doomed for extinction as production eventually shuts down and existing stocks are depleted? Is the market for tube equipment because of lack of tubes going to disappear?

No, but the designs of old are being replaced by new technology that is not so dependant on old popular tube designs.

The Aesthetix Io used 4 12AX7 in the first gain stage and the new Audio Research uses a transistor. Other companies use a transformer or both transformer and solid state together. Audio Research went with four 6H30 dual triodes in place of 6922 or 12AX7. Older model Audio Research phono stages and line stages used 6922 but ARC abandoned them because of quality control problems from modern tube suppliers.

I'm surprised Aesthetix has not developed a new input circuit for the Io, it's a world class piece and among the best ever made but last I heard there were maybe one or two tubes in 100 that made the cut after sorting and testing for that first position.

NOS Telefunkens (back when they were available) were frequently good enough out of the box to do the job. Today even the "select" NOS Telefunkens have been picked over, tried and returned to the box until finding a truly NOS perfect pair or quad for phono is a massive undertaking.

The last time or two I needed them for my Io (before I sold it) Andy at Vintage Tube took months to get perfect stocks and he is among the best in the business at finding them.

I think there will be changes in circuit design to accommodate what's available. Those that don't change will find it increasingly difficult to tube up properly when needed.

All that being said, the old designs are magic, the new tubes like the 6H30 were designed for use by Russian Military and although they may test great and have fewer problems than new 6922 from Russia, they are far more electronic and solid state sounding.

Some newcomers are going with transformer coupled circuits combined with NOS Euro communication tubes like Siemens and Mullard to get reliability, low noise and great sound.

There are lots of ways to get there. Tubes are here to stay, at least for as long as most of us will be around.

Thanks for the info, Albert. I really don't know much about the 6H30s.

Sgn,
It's not a new tube, it was designed for Russian military. Some people love them and some don't. I respect the design and emphasize the fact manufacturers need current production stocks and Russia has thousands and thousands of these.

That being said, I've known BAT owners that search out older stocks of 6H30, preferring them to what is more easily available today.

There was a short thread about this here at Audiogon, link below:

http://forum.audiogon.com/cgi-bin/fr.pl?htech&1252692091

I respect ARC and if I didn't own what I have now I would be trying out the new Ref 5 and new phono from ARC.

ARC style is nice, clean lines and no nonsense controls. Their workmanship is first rate as is their chassis. The new remote control is superb and performance from later models rivals anything around.

Companies like ARC and BAT have had time to work with these new tube and "tune" the circuit to sound best. I'm not crazy about the BAT sound but they are an excellent company and build a first rate product.

Tubes are a huge influence on sound but even with the newer stuff, some designers are able to coax out the best. A perfect example is the Russian 6C33C power tube, I've never liked that tube or heard a amp that used them that made me want to buy, until I heard the little Lamm 18 watt SET.

I'm a power guy, so probably never own the Lamm but I respect the hell out of it and the designer that got that incredible tonal balance and texture out of what I always thought was a poor sounding tube.

In time there will be other tubes and other designers that wring out the best from tubes, probably some that we don't even think of for audio at this moment.