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

Showing 5 responses by fletchj

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, there was no reference to myself, as anything. I did not even state, what my experience, with tubes are, nor for that matter, what experience I have. I only stated, what one should look for. Everything else, you have assumed, is based on what is going on, in your mind, what you inferred, not what was stated. If you agree, that a knowledgeable, and dependable dealer is important, then we are in agreement. I am not advertising myself, I am simply stating, what I think, about tube myths. That is what this forum, is for.
When one offers information, one should be knowledgeable about the information, one is offering. Think aboutit, if a doctor told someone, that they should visit a doctor, for an ailment, they were suffering from, is he advertising himself, or offering, what he thinks, is pertinent information?
You know, I have taken a lot of criticism, for offering infomation, that many thought, new tube users, might find useful. Although noone seems to disagree, with the validity of the comments, they seem wholly distrustful, of my intentions. As a knowledgeable tube person, who has dealt with tubes, for over 30 years, I thought I'd pass on some simple info. Do not worry, this will not happen again. I have no need to drum up business, that is what my adversements, on Audiogon, are for. So you may thank Herman, Newbie, Viridian et al, for censoring information, that may have been pertinent, for a tube novice. Maybe they can answer some tube questions, since they seem to be so intuitive, as to ones motives. So fellow Agonners, I have been gagged, by the self righteous few, who have decided, who, and how, information, should be proffered.
I've read this post many times, and its so revealing of what's happening on social media today. They latch on to a message, and tell its readers what the massage is trying to do, instead of just reading. Always some underlying reason, or conspiracy at work. Nobody does anything, out of the thought of their fellow man, or so they say. Have they ever thought, that they are so corrupted in thought, that they only see corruption? How can you be open minded, when you can discern the bad intentions of others, without them doing anything bad, just something that can be construed as bad? But YOU know their reasons, regardless of what they say. Even if their explanation, makes sense, they're perpetrating. No need to defend yourselves, you're right.