Jeff Matthews Posted March 13, 2006 Share Posted March 13, 2006 Okay, what's up with people always using the phrase "tube watts?" When you say "these tube amps are 20 watts," the amp's afficionado's say ".... But these are tube watts." Quote Link to comment Share on other sites More sharing options...
Deang Posted March 13, 2006 Share Posted March 13, 2006 From http://www.ccdemo.info/SportsAndHobbies/TubeElectronics/TubeElectronics.html "Electron tubes are thought by many to be well suited for high fidelity audio applications. Technical observers report that when a tube amplifier is operated near its power limits that the distortion produced is the addition of even harmonics (even multiples of the fundamental freqency), while transistor amplifiers produce a distortion consisting of odd harmonics. Many listeners think that the addition of even harmonics is acceptable and even pleasant, while finding odd harmonics are harsh and disturbing. The addition specific proportions of even harmonics to a pure sine wave will produce a sawtooth wave, which has a timbre similar to a reed instrument such as a clarinet, while a similar addition of odd harmonics will produce a square wave, percieved as a harsh buzz, similar to the sound of a kazoo. Click here for a diagram of harmonic addition. On loud transients, the current capacity of the tube and a tube-rectified power supply will limit with a gradual fall-off, where solid state will "clip", introducing harsh high frequency components that can even damage speakers. Thus many solid state amplifiers are overbuilt, with extra capacity to avoid the introduction of this distortion under conditions rarely encountered. Tube amplifier watts are said to be "bigger", in that under extreme conditions a given musical passage will sound better on a tube amplifier than on a solid state amp of the same wattage. Modern mass market solid state equipment is now built to meet specific manufacturing cost targets. (Some think that there was a "golden age" of Japanese solid state equipment around the 1980's, when the technology was mastered and engineers rather than accountants still ruled.) It has been my experience that an old mid priced tube amp sounds much better than modern mid priced solid state equipment (using the same speakers and source), especially in the way that instruments in a symphony orchestra's string section will retain their individual identities, rather than being muddled together." Quote Link to comment Share on other sites More sharing options...
D-MAN Posted March 13, 2006 Share Posted March 13, 2006 Oh, I get it - tube watts are fatter than REAL WATTS! Do you guys really buy that? DM Quote Link to comment Share on other sites More sharing options...
Jeff Matthews Posted March 13, 2006 Author Share Posted March 13, 2006 Good response. I see what you mean by the "odd" vs. "even" distortion. As to the idea that some say tubes sound "bigger," I noted you stated that they would sound "bigger" under extreme conditions. I take it you mean when clipping. Correct? Quote Link to comment Share on other sites More sharing options...
NOSValves Posted March 13, 2006 Share Posted March 13, 2006 Plus a quality AB Push Pull tube amp has near double its steady state power rating for transient peaks without audible distortion. So a quality 20 watt AB Push Pull amp has the ability to operate similar to a 40 watt class A tube amp or SS amplifier when playing music since in most cases with "normal people" they would never push an amp to a point where you were using all its steady state power rating.(Of course you would never qualify as normal []). Craig Quote Link to comment Share on other sites More sharing options...
NOSValves Posted March 13, 2006 Share Posted March 13, 2006 Oh, I get it - tube watts are fatter than REAL WATTS! Do you guys really buy that? DM Absolutely!!! Quote Link to comment Share on other sites More sharing options...
Jeff Matthews Posted March 13, 2006 Author Share Posted March 13, 2006 I just want to make sure I understand..... Let's say you turn up the volume to 1-watt output on a tube amp, and you do the same for an SS amp. Is this "tube watt" going to sound like more than 1 SS watt? Or will it just sound harmonically different? Quote Link to comment Share on other sites More sharing options...
sfogg Posted March 13, 2006 Share Posted March 13, 2006 " Plus a quality AB Push Pull tube amp has near double its steady state power rating for transient peaks without audible distortion." So do quality SS amps. Its listed as dynamic headroom on the specs of some amps. Shawn. Quote Link to comment Share on other sites More sharing options...
D-MAN Posted March 13, 2006 Share Posted March 13, 2006 "Absolutely" That's a giant CROCK. And YOU should know better, Craig! Measuring wattage is measuring wattage into a load, kids: P=IE (power (in watts) = current x voltage). Add to that the criteria for resolving RMS and that has absolutely NOTHING to do with output stage topology. Wattage is wattage is wattage. {edit} However, if by "fatter" we mean dirtier and all that entails, then ok, agreed. But not louder. DM Quote Link to comment Share on other sites More sharing options...
sfogg Posted March 13, 2006 Share Posted March 13, 2006 "Is this "tube watt" going to sound like more than 1 SS watt? Or will it just sound harmonically different?" No, it won't sound louder. You *might* notice a difference in harmonics but at 1w the differences are going to be very minor. The place differences could be more pronounced is simply in FR if the speaker is a reactive load. The way the tube amp and the SS amp will deliver power to a varying impedance will be different which will alter the power delivered at different freqencies. IOW... the FR could vary between the two. Shawn Quote Link to comment Share on other sites More sharing options...
Jeff Matthews Posted March 13, 2006 Author Share Posted March 13, 2006 Here's a write-up where this was used (which is similar to what I've seen a number of people write).... "The Waves may only put out eight tube watts (but remember tube watts ain't solid-state watts)..." This seems, to me, to clearly state that while you may think 8 watts is not enough, remember, these are "tube" watts, and a "tube" watt is more than an SS watt. Quote Link to comment Share on other sites More sharing options...
sfogg Posted March 13, 2006 Share Posted March 13, 2006 Dean, I know you are just quoting from some other source but the whole tubes = even, SS = odd is misleading. Lime most things it isn't that simple. There are plenty of SS amps that put out more even order then odd order distortion and there are also plenty of tube amps with more odd order then even order. Depends upon the design far more then if it is SS or tubes. Shawn Quote Link to comment Share on other sites More sharing options...
NOSValves Posted March 13, 2006 Share Posted March 13, 2006 " Plus a quality AB Push Pull tube amp has near double its steady state power rating for transient peaks without audible distortion." So do quality SS amps. Its listed as dynamic headroom on the specs of some amps. Shawn. Go get what you consider a quality 20 watt ss amp and I'll whip up the same we will meet half way between are locations at some forum members house and I will prove you dead wrong. We don't need to go any further with the discussion. would this apply to your world class TEAC amps?? Please say no...... Craig Quote Link to comment Share on other sites More sharing options...
steamer Posted March 13, 2006 Share Posted March 13, 2006 Well Jeff here is some more info that might give you some insight.I dont know what to believe but I sure like the sound of tubes. http://www.audionote.co.uk/technical/amppeak/ Greg Quote Link to comment Share on other sites More sharing options...
sfogg Posted March 13, 2006 Share Posted March 13, 2006 "This seems, to me, to clearly state that while you may think 8 watts is not enough, remember, these are "tube" watts, and a "tube" watt is more than an SS watt." The difference is that depending upon the design a tube amp may have 'softer' clipping then some SS amps. Instead of the top of the waveform being a flat top (hard clipping with its attendant distortions) the top basically sort of compresses. The action acts like a limiter and in effect compresses the dynamic range of the recording. The peaks don't play much louder past that point... just the quieter stuff gets closer to the peaks. Of course if you try and push it harder it will clip harder and distortion will jump up. But here is the thing. Not all tube amps act this way. Not all SS amps 'hard' clip. 'Soft clipping' is a design goal in some SS amps. I think for the clipping to be soft the designers basically setup the amp so that the input stage runs out of gas before the output stage and compresses like some tube amps. And there are other SS amps that won't exactly clip at all. McIntosh amps with 'PowerGuard' are like that. What they literally do is dynamically lower the input signal into the amp when they are approaching the point where the amp would clip. This in effect acts as a limiter/compressor to keep the signal into the amp below the point where the amp would actually clip and introduce distortion into the signal. You can run a SS Mac amp with PowerGuard right up at its limits and it behaves a lot like what some thing all tube amps do. Shaw Quote Link to comment Share on other sites More sharing options...
NOSValves Posted March 13, 2006 Share Posted March 13, 2006 "Absolutely" That's a giant CROCK. And YOU should know better, Craig! Measuring wattage is measuring wattage into a load, kids: P=IE (power (in watts) = current x voltage). Add to that the criteria for resolving RMS and that has absolutely NOTHING to do with output stage topology. Wattage is wattage is wattage. {edit} However, if by "fatter" we mean dirtier and all that entails, then ok, agreed. But not louder. DM This was not a crock MUSIC IS NOT A CONSTANT LOAD and you should know that. What I stated was absolutely true!! Craig Quote Link to comment Share on other sites More sharing options...
D-MAN Posted March 13, 2006 Share Posted March 13, 2006 Perceived loudness is not the same as measured wattage. And yes, I know, but NOBODY measures wattage into a reactive load, do they? They use a fixed dummy load and nobody uses music as a source to measure wattage. That would be pointless. They measure current x voltage (2.83v sound familiar?). DM Quote Link to comment Share on other sites More sharing options...
Duke Spinner Posted March 13, 2006 Share Posted March 13, 2006 Mmmnnnnn..... Dana ... has it......[] Quote Link to comment Share on other sites More sharing options...
NOSValves Posted March 13, 2006 Share Posted March 13, 2006 Dman, Read it and weep and according to Shawn I guess some SS amps have the same ability although I have never witnessed it and find it hard to believe the way the dead clip and drive you out of the room compared to a similar rated tube amp. Quote Link to comment Share on other sites More sharing options...
Jeff Matthews Posted March 13, 2006 Author Share Posted March 13, 2006 I read about as much of that article as I was willing to bear. It seems much of the focus is on clipping. Why get an amp that clips "good" when you can get an amp that does not clip at all? Let me maybe refine the question. Assuming no clipping is occurring, is a "tube" watt going to sound like more than an SS watt? Quote Link to comment Share on other sites More sharing options...
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