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Tube myths

Many have asked me the same question, "How does the tube sound?" Well, the sound of the tube, is affected by numerous factors, such as circuit interaction, voltage applied to the tube, system setup, use of the tube, etc. All these things, combine, to make the sonics that one's hears, in his system. A bright sounding tube, in a mellow system, will appear to sound neutral. A tube that accentuates, the presence region, in a room with a dip, in that same region, will sound neutral. A neutral sounding tube, in a etched sounding system, will pass the etched sound along, and appear to sound etched. See what I am getting at? It's very hard, to know how a tube will sound, to the end user, in his/her room, and his/her system, based on how it sounds, in yours.
Different tube manufacturers, had a "house sound", whereas the tubes, they manufactured, tended to follow. But to what degree, the end user, will hear this sound, is solely influenced, by the various factors.
Another question frequently asked, "Is the tube NOS?" Manufacturers published a "spec sheet", that listed a set of parameters, that determined, a NOS(New Old Stock) tube. In order to determine if a tube meets this specification, one must determine, the test conditions, and invariably, test for voltage gain(emission). The voltage applied to the tube, must meet the manufacturers specs, to determine, if the emissions, are what the manufacturers specified. The NOS spec, is 99% of the time, lower, than the actual emissions, of a true NOS tube. A true NOS, unused tube, tested, according to the manufacturers spec, will almost always exceed the NOS spec, by approx 10%. A tube with an emission reading of 100%, tested accordingly, usually indicates, some use. However small, it is still used. Not knowing the history, of the tube, it takes, a true emission tester, that the applied voltage, can be varied, and a working knowledge(experience) to determine, to any truthful degree, that a tube is NOS. Mutual conductance testing, is a great way to match tubes(except power tubes), but is very unreliable, in ascertaining, whether a tube is NOS. The cosmetic condition(the way a tube looks) means nothing, as far as to whether it is NOS.
I will periodically, post more info, on the various, tube myths, that are floating around the web. My best advice, is to find a tube dealer, who is willing to stand 100%, behind his products, and knowledgeable, about the product, they are offering.
fletchj
dekay's avatar
dekay
5,703 posts
 
Herman:

Yes, it would be nice if the "private" tube dealers would @ least register themselves as "industry" pro's.

Another one that does not comply (in regard to this) is Fatbottle @ Audio Asylum.
pbb
1,140 posts
 
Newbee "Why spend your money if you don't have to". Are you kidding? The whole point of high-end audio is to filter the sound through one's pocketbook. The sound is obviously dollar dependant. Most of the time you don't even have to read between the lines, the posters will gladly opine that more money means better sound, the exceptions being few and far between. Among the sacred cows: NOS tubes. How many tubes were produced and not sold to have still have stock on hand. Unless "NOS" should not be taken literally.
newbee
4,794 posts
 
Pbb, I tend to look at mosts things cynically, sort of like being an agnostic. There are a lot of things that I believe may well be nothing more than an illusion, but until I have personally experienced it I reserve judgment. I think a lot of the reverence for NOS tubes is hype by financially interested sellers, HOWEVER there really is better NOS stuff that can't be duplicated in current production and demand determines the price. If you can afford it why not spend your money on it or would you rather have, say a better watch, car, etc? One of my favorite observations is "you may not get what you pay for, but you will never get more than what you pay for". Some people who can afford it appreciate the difference and are willing to buy it. Good for them, they are enjoying their lives.
fletchj OP
91 posts
 
Marankanetz"Good ears can fool you, no matter how golden they are. If a tube is blown after a short period of time... Ears do not fool you. What you hear, you either like, or you do not like. Trust your ears, as to what you like, not what someone says, you should like. A dealer who stands behind his product 100%, will take into account, that some tubes will fail, early in their use, like all electronics, and allow for some compensation, such as a replacement warranty. No amount of testing, can guarentee, that a tube, will not fail.
Herman, This is why I stated, that it is important, to find a dealer, that is willing to stand behind his product. The reason, you need one with knowledge, of tubes, is because manufacturers routinely bought other manufacturers tubes, and sold them, under their own brand. A knowledgeable dealer, will know exactly what he is selling, not what is printed on the tube. Also, certain tubes, have a propensity, to be microphonic, this should also be mentioned, to potential purchasers. There are a lot of new tube users, and they surf the web, for comments, about tubes. A lot of applications, paying a premium price, for premium tubes, is not neccessary. Why pay, for some difference, you will not hear? A dealer interested in providing you with the best sonics, and value, will disclose this information to you. The purpose of the posting, was to answer the most frequently asked questions, that I receive. There are a lot of tube dealers, that put the purchasers interests, first, as it should be. What I stated, is that it is worthwhile, to seek them out.
As far as NOS vs current production, there is nothing wrong with either. Tubes are not priced, according to quality, or sonics. They are priced according to availability, rarity. A tube that costs $200, is not neccessarily 100 times better, than one priced at $20. It's just much harder to find, and therefore, by the laws of supply and demand, priced accordingly. A rare tube, carries a high price, regardless, of it's perceived sonics. I myself do not hear vast differences, between the revered tubes, and the later vintages, of the same manufacturers. But small differences, mean a great deal, to others, and they should be the final arbiters, of the tubes relative value. You must understand, if these things I state, are obvious to you, then this post, was not meant for you. It was meant for those just starting in our wonderful hobby, of using tubes, and needed some straight info.
herman
2,277 posts
 
This is a discussion forum, not a place to advertise.

I do not disagree with the information you have provided regarding tubes and dealers. What I take exception to is your stance that you are doing this as service to your fellow hobbyist. When you initiate a post promoting yourself as a knowledgeable, caring provider of NOS tubes, you are advertising.
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