Emission Labs. Information about life time of electron tubes.

Technical Bulletin TB-12.

What makes good tube sound?

Ever since we make and sell tubes, one of the most occurring questions is: 'What tubes must I buy to get ultimate sound out of my equipment'. Now, if people ask the question that way, it is no beginner's question. For that reason, answering it is difficult. Some semi specialist jump into the gap, where real specialist can not give a simple answer, or must even sometimes give an negative answer. Same as in medicine. When the real doctor can help, people go there. If not, they go to people with a lower qualification, to pay a higher price. Some tube doctors have strange theories. In several case you are listening to people with complete lack of engineering knowledge, and they can 'hear' what an engineer can not measure. An experienced technician though, 'can not simply erase the facts from his memory, and replace that information by 'belief'. (This is a quote from Immanuel Kant actually). On the forums, believers team up with each other, and discuss how they hear phase errors above 20kHz. Before you know it, you are in the middle of a dead serious discussion which lacks every technical background. This is not leading anywhere.

Be cautious for black magic.

That can be self-invented treatments, self invented test methods, or extremely tight selected parameters that don't benefit mostly the profit of the seller. Fantasy is set no limits, like CD de-polarizers, direction-sensitive interconnect cables, or 'sound stones' to place near your speakers. If you are searching for these kind of experiences, we have none to offer here. Rather a few very practical things are mentioned here.

Back to the question: What makes tubes good sound?

The answer we have, is based on a simple principle: Sure you heard the expression 'HiFi Chain' before. This is a chain indeed. Sound is passed through very many elements, more then you may be aware. Each has a function, and very few of them have the function to change the sound, like for instance a tone control has.

If one element in the chain that is weak, it ruins the good function of all others. So a chain can not be stronger than it's weakest element. Meaning each element must have equal quality. Let's give an example of a wrong choice. Suppose you have 10000$ to spend, and you spend 9500$ on the amplifier, and 500$ on the speakers. It is obvious that this will not give the best sound for your 9500$. You need to balance the cost between speaker and amplifier. For 'just' 1000$ more you have 1500$ speakers, which will make a big difference, whereas the amplifier of 9500$ or 8500$ will not sound so extremely different. This of course is logical.

When it comes to replacing tubes, the above rule is also valid, but many have learned it the hard way. Suppose the listener has the idea, tubes may sound better than transistors. Then an expensive r amplifier gets replaced by a tube amplifier. Being aware that this is an experiment, the amplifier may not cost much. A 5000$ transistor amplifier gets replaced by cheap amplifier from Ebay, for just 400$ new, including shipment and all tubes. The hope is, this will at least give 'tube sound' not knowing yet what that might be, but when that sounds better, the user plans to buy a more expensive tube amplifier. After a while, they users comes to the (valid) conclusion the sound is disappointing, and the suspected elements are the Chinese tubes. The frustration is very large, when they find out a set quality tubes costs 2x more than the whole amplifier without tubes. So the Chinese tubes are used further, until they get weak. It can take up to two years, and even then, when they get replaced by expensive tubes, the result is only average. This is because in the amplifier are likely output transformers, wound on cores, same as for mains transformers. If you are in a situation like this, better cut out the weak elements completely.

The following happened to me. In 2008, we presented the EML 2A3-Mesh tubes on a HiFi show, playing with a Yamamoto A-011 amplifier, and a set of exclusive horn loudspeakers. Actually build by a person who holds a still valid patent on dipole bass speakers. So when I say great speakers, I mean great speakers! There was a middle aged woman listening to the amplifier, and she returned every day of the show. She came with her husband, and bringing vintage Pink Floyd CD's, asking to hear them, over and over again. I saw she was crying. I asked if she had a problem, but she said she just liked the music that much. ok it happens. Then what she told me, moved me so much, I want to tell this here. The sound was so wonderful, but the reason of her sadness was, she spend 20 years of her life, unknowing such a sound excists. She asked if she could buy the loudspeakers, after the HiFi days are over. Which was not planned for, but it was possible. She was so happy about this, and cried again, because she said she can not get back those lost years of listening to lower quality music. Pink Floyd music is very important for both her and her husband, it is part of their lives. This is a true story.

To my opinion, a well balanced set of tube gear is combined the following way:

1) Begin with top quality tube grade speakers. Requirements to speakers for a tube amplifier are higher than for a transistor amplifier. Such speakers have following properties:

2) Connect to this to the tube amplifier

3) Put in there the best quality tubes

When you have all the above set right, you have come at this point here. Even a high cost tube will not be overly expensive compared to what good equipment costs, and sure with good equipment you will hear that!

'45 tube' amplifiers
'2A3 tube' amplifiers
'300B tube amplifiers, recommended tubes
Some items to take care of.