Vintage tubes - facts, science, technology & empirical evidence VS. marketing, myth & hype


Sorry. Long post. I hope you find the premise interesting and useful. And hope my writing below is not too bone-headed. Please feel free to correct or point out any misstatements or errors in my thinking.

This is not intended to be a controversial thread. At the outset I am not staking out a position. My questions are sincere and are not intended to poke anyone in the eye. The ultimate focus of my question has to do with the performance of vintage tubes as they compare to current production tubes. I am asking because it seems to me that there is a lot of marketing hype & perhaps some myth and wishful thinking when it comes to vintage tubes. There is also a rich body of collective experience. And, it seems, consensus that certain brands, factories, vintages and specific types of tubes are better than their peers and are "worth" the extra money they command. Of course, the principle of diminishing returns applies here. Right?

Do measures of voltage gain, transconductance, plate resistance, noise and microphony tell the whole story? Are they sufficient for predicting performance? To what extent do they predict longevity? Or is longevity primarily a function of empirical collective experience? What about the materials science aspect of vintage vs. modern tubes?

It seems that every company that produces tubes works hard to refine their design and balance innovation with "faithfulness to the vintage design", production processes, materials to make good sounding tubes. Even so, not all tubes from a given factory will perform the same, hence the testing and grading relative to the measures above and the consequent sorting into hierarchies of ascending levels of performance and price.

It also seems to me that performance will be closely tied to the circuit design and execution. A solid design would, it seems, be robust and produce excellent results with a wide range of tubes. A poor design might drive a tube in a way that is hard on the tube or requires a very specific technical characteristic for the circuit to perform well. Either of these situations could cause a user to come to completely different conclusions about what vintage/modern tube is "good" or excellent.

I have read some posts on this forum from certain individuals in which all "modern" or current production tubes or tubes produced by certain countries are dismissed out of hand. This seems like prejudice. Or it could, I suppose, reflect accumulated frustration with a given tube/brand/maker/etc as it performs in a given circuit.

I suppose I’m ultimately asking those who’ve more experience and who have invested more $$$ in tubes and tube rolling across various kinds of equipment to share their experience and opinions.

Thanks, in advance, for your patience. I hope to learn from those who are willing to share.




128x128markusthenaimnut
Let me be, perhaps, a little clearer in explaining what I'm thinking. I think it takes years of experience to really know your way around vintage tubes. Without that experience we're relying on others to guide the way. Isn't that one of the purposes of this Forum? To share our experience?

It is.    

My experience is, yes tubes do sound different. It should be obvious they are not all the same, if only for the simple fact sometimes one blows out while another one of the same type and brand and age runs for years. They all pass the same QA measurement tests so that should tell you all you need to know about the efficacy of measurements. This much is all obvious as can be and so it remains a mystery why anyone still wonders about such things.  

This does not mean there are no physical properties might that account for the superior performance of certain tubes. The most experienced and knowledgeable man I know on the subject, Raven Audio's Dave Thompson, told me he heard from an engineer who worked at the factory where some of his most cherished tubes were made that the equipment used then pulled a vacuum 20% greater than today.   

So there are reasons, and let me know the next time you see the inches of mercury vacuum stat on a tube.   

Even then I would have to say that is just one on a very long list of factors. Tubes are a connosseur's game. Reliable information is so hard to come by that I gave up years ago. Until learning about Raven and Dave. Now thanks to Dave I know whatever I buy will indeed be well worth the extra. Just last night I swapped out a TungSol and moved some of Dave's around to the rows he recommended, and immediately experienced extension, nuance, and real live emotion like it was a whole new amp.  

These are tubes collected from a lifetime of searching and comparing. This transforms tube rolling from a crapshoot to just about the easiest and most rewarding thing around. All you have to do is buy a Raven amp. The stock of these NOS wonders is limited, and when they are gone they are gone. He only sells within the Raven family. So there you go.



Excellent post from @atmasphere.

@markusthenaimnut, as you already mentioned, the following tube sellers effectively mitigate the risk of purchasing vintage tubes. They also will provide recommendations based on your component(s). They are worth repeating.

Andy Bouwman - Vintage Tube Services: http://vintagetubeservices.com
Brent Jesse Recording: https://www.audiotubes.com
Upscale Audio (buy Kevin’s Stash grade): https://upscaleaudio.com/collections/vacuum-tubes

I have used all the above and can recommend them without hesitation. I would avoid E-Bay sellers, unless you either know them through personal experience, or through a trusted referral.

Other members often suggest:
RAM tubes: http://www.tubeaudiostore.com
@tvad and Ralph who actually engineers some of the finest tube gear on the planet, have it correct as do others who mention reputable experts who do also sell Tubes. Andy is a gem, have a look at his Arsenal of test equipment and his listening skills superb. Also consider the genius of Roger Modjeski ( rip i miss him ) and RAM tubes. One point being, there is more to nos and new tubes than just newly discovered Raven. For example the particular genius of Jim White of Aesthetix. While the use current production tubes with extra grading far and above final factory QC, they point customers to Vintage Tube for upgrade help. i could go on….

I helped build some of the most advanced and powerful tubes in orbit above earth, i can assure you it is a high precision business requiring very tight process control and quality ALL along the way. RAM tubes undergo some of the most rigorous testing, however lint in the tube ( contamination ) plagues many modern tubes.

Scarcity is not diminishing returns

Many designers ignore the RCA tube design manuals at peril

Some designers and firms have a culture of designing for tube longevity two that instantly come to mind McIntosh ( under Gordon Gow ) and Music Reference. There are more.

have fun, enjoy the journey…..


also for the OP, it helps IF you focus on tubes deployed across your system. My reference system , with various input path contains 25 tubes…..ah which to work first ?