"Tube" watts....

[sfogg]

Craig,

"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 "

Put your money where your mouth is. Do what you originally claimed. Why backpedal now and cut the wattage to the SS amp in half from your original statement?

"This was not the case before SS came along."

NSS. Before SS came along recommending amps with 5x the needed power would have been recommending tube amplifiers that almost no one could afford. Not a good way to sell a speaker.

"I still have never experienced an SS amp that shows any sign of USEABLE headroom above its rated steady state output playing music."

That just shows how inexperienced you are.

If you put all aboce mentioned on a steady load and pump sine waves into them and you get no explanation as to why it is BUT IT IS."

You may not get an explanation but that doesn't mean others don't understand it performing similiar measurements. I already explained the difference in clipping behavior between the two with some amps. That is the difference you are hearing. Some tubes amps act like they have limiters attached to them when you near max power to keep the clipping from getting really nasty quickly. It is not the difference in 'peak' power, it is the difference in overload characteristics.

" I guarantee you a 20 watt SS amp will drive people out of the room before a 20 watt tube amplifier SPL wise."

And I guarantee you that will not always be the case. Put in a SS amp with something like 'Power Guard' and the tube amp will get nasty while the SS amp won't.

Shawn

[NOSValves]

Thanks M8o,

Due to the efficiency of my speakers and the fact that all of my horns are driven by amps with at least 3-6dB of headroom, I see no reason that any of this really applies in my situation. My midrange and tweeter horns are rated at 50 watts RMS with a peak handling capacity of 200 watts (6dBs). My smallest amp is 100 rms (3dB on the tweeter, which will never see more than a couple of watts anyway) and then a 225 watt RMS amp on the midrange drivers which usually never see more and a few watts RMS. Clearly I am never even close to running these amps anywhere near their rated power.

Besides talk is cheap, all this psycho-babble is tiresome. Come on Craig make a trip to Florida and prove me wrong. Take the wife to Disney or the beach then spend a day listening.

What would I have to prove you wrong about??? With Klipsch speakers you would have to have lower watt SS gear to demestrate what I'm stating. If we pumped a 100 watts of tubes or SS into your speakers we would be chased out of the room from SPL clipped or not (at least I would). This is the reason I mentioned 20 watts it would be a power rating where in a reasonably large room we could hit the magic 20 watts to experience what SS and Tube sound like when pushed to there limit. With 100 watt amp we could never accomplish it without damaging are hearing[].

Craig

[Jeff Matthews]

"Were not talking about measured power were talking about perceived power playing music."

Well, that's SPL in db's not watts!

Watts are electrical - Just trying to help you out here, bub.[]

DM

BUB! Now that is a cute name []

No help needed.. Peak instantaneous watt abilities is what I'm talking about. To tell you the truth I have no idea how it can be measured. It would take some test equipment that reacts seriously fast which I can not afford. While you keep bringing up steady state rating into a dummy load running a single sign wave. That ain;t music BUB[]

By the way saying someone is stating a "CROCK" is usually not considered helping them out.

Craig

I think he is just using a lively tone for his argument and does not mean to offend. But anyway, talk to me about what you mean regarding a difference in "peak instantaneous watt abilities." Is this something that varies when clipping begins. Or is it ever present in the music, even at more moderate volumes?

And I'm just replying in a like manor!!

Peak instantaneous watt abilities = It's the ability for an amp to reach beyond its "Steady State wattage" for very brief transients. I personally think tube amps especially quality PP AB do this better then most any other amp. Obviously Shawn does not. But that's not surprising some engineer types have trouble believing anything they can not see on there test equipment. I'm sure with enough available cash and technical no how a power test setup could measured this to some degree. I just know its way beyond my wallet. The big boys in the business most have a way since they rate amps in this fashion. Although it wouldn't surprise me if they use some mathematical equation to come to a educated guess.

Craig

Okay, but back to the question I posed earlier. If you have a high enough steady state wattage, doesn't this take away any consideration to be given to "peak instantaneous watt abilities?"

Here, a while back, we were taking readings using my crappy voltmeter, where you speculated that I was probably only using about 30 watts to reach those earbleeder levels. Was there some greater amount of wattage that might have been used for instantaneous peaks - like say, 60 watts or 120 watts?

[NOSValves]

Thanks M8o,

Due to the efficiency of my speakers and the fact that all of my horns are driven by amps with at least 3-6dB of headroom, I see no reason that any of this really applies in my situation. My midrange and tweeter horns are rated at 50 watts RMS with a peak handling capacity of 200 watts (6dBs). My smallest amp is 100 rms (3dB on the tweeter, which will never see more than a couple of watts anyway) and then a 225 watt RMS amp on the midrange drivers which usually never see more and a few watts RMS. Clearly I am never even close to running these amps anywhere near their rated power.

Besides talk is cheap, all this psycho-babble is tiresome. Come on Craig make a trip to Florida and prove me wrong. Take the wife to Disney or the beach then spend a day listening.

What would I have to prove you wrong about??? With Klipsch speakers you would have to have lower watt SS gear to demonstrate what I'm stating. If we pumped a 100 watts of tubes or SS into your speakers we would be chased out of the room from SPL clipped or not (at least I would). This is the reason I mentioned 20 watts it would be a power rating where in a reasonably large room we could hit the magic 20 watts to experience what SS and Tube sound like when pushed to there limit. With 100 watt amp we could never accomplish it without damaging are hearing[].

Craig

[NOSValves]

"So, now that that is out of the way, a more intelligent discussion of tubes vs. SS can take place. It seems the consensus is that the distortion created by tubes is of a different (even) order than the distortion created by SS (odd). I noticed on the specs NosValves posted of the MK amps that the distortion percentages are substantially higher than the specs usually found in SS. I think it was along the order of 1% distortion in the tubes, whereas, we often see something like .05% in SS. So, is there any science that compares 1% "tube" distortion to .05% SS distortion? Or is this topic beyond any meaningful scientific analysis?" ========= Good lord, it's 1972 all over again. Mine has 0.001%THD and 120W, therefore it must be better than yours with 0.1%THD and 50W. The Pioneer SX-1080 simply the only amplifier will ever need. And hey-it's in a receiver with a boatload of knobs too? Oh, I know, let's buy amplifiers by the pound! Or, how about by the size of the heatsink? Output tubes? No wait, mine has a bigger transfomer! Mine has bigger caps - a hefty 50,000uF - it "must" have great bass, huh? You have a thing called ears. They can be a very useful judge of amplifier sound quality. Try it sometime, you might just amaze yourself! Listen critically to a variety of amplifier designs, and eventually you'll reach the only meaningful consensus - yours. md

Hurray!!

[6foot8]

Ok Craig you can still come and listen if you want. My wife and I would be happy to grill up some good steaks and veggies.

[NOSValves]

Okay, but back to the question I posed earlier. If you have a high enough steady state wattage, doesn't this take away any consideration to be given to "peak instantaneous watt abilities?"

ABSOLUTELY

Here, a while back, we were taking readings using my crappy voltmeter, where you speculated that I was probably only using about 30 watts to reach those earbleeder levels. Was there some greater amount of wattage that might have been used for instantaneous peaks - like say, 60 watts or 120 watts?

ABSOLUTELY no meter I have ever seen can keep up with music. The same can be said about SPL meters. This is why testing gear with sine waves and square waves is not the final word on anything. Sine waves and square waves are not music!!!

[NOSValves]

Ok Craig you can still come and listen if you want. My wife and I would be happy to grill up some good steaks and veggies.

Why thanks I may just take you up on that someday.

[6foot8]

Just let me know Craig. My wife and I are very normal people. I am not all that whacky most of the time.

[jacksonbart]

Just let me know Craig. My wife and I are very normal people. I am not all that whacky most of the time.

Thats exactly what I would expect most psychopaths to say.

[NOSValves]

Just let me know Craig. My wife and I are very normal people. I am not all that whacky most of the time.

But I am far from normal []

[6foot8]

Just let me know Craig. My wife and I are very normal people. I am not all that whacky most of the time.

Thats exactly what I would expect most psychopaths to say.

Maybe we'll have Bart for dinner...[6]

[SilverSport]

...with farva beans and a nice bottle of chianti???

Bill

[meagain]

Jeff - I do not understand why you are still on this "watts/clipping/slam" issue. Or why you seem to still hold the belief that a lower watt amp or tubes can't possibly give you want you need. There's more to life than just how loud you can crank it without clipping.

Here's the thing... if you were shopping for a diamond which would you rather have? A 5 carat with occlusions, or a flawless 1 carat? I'm thinking you'd buy the 5 carat.

When you were at Born2rockU's & played the gear to the point he had to physically leave the room - did you also do listening sessions for such things as vibration of strings against a fretboard & how lifelike/accuate that sound was? Critical listening and not just how much you can get your innerds to rumble?

It just seems like you still have a hard time accepting that you can use a lower watt and/or tube amp and get that high quality sound (1 carat flawless diamond) AND STILL get quality loudness. If you still hold that to be true in your head - I contend you are wrong-o.

[6foot8]

...with farva beans and a nice bottle of chianti???

Bill

Broiled Cajun style or roasted??

[pauln]

This is an excellent question because it's answer bears on the inate superiority of tubes to SS.

http://www.decware.com/debate2.htm READ this - it addresses this very question about tube watts

First, ALL amps spend some time in peak demand overload, but what is important is how the amp responds to that. Suppose you have a SS amp and a tube amp; what happens to the harmonics as you go to +3dB, then +10db, then +15dB into overload?

Basically, the SS brings in the higher harmonics faster, the tube amp more slowly. For example, (a made up example to illustrate...)

SS at +3dB shows some 3rd, a little 5th

SS at +10 shows lots of 3rd and 5th

SS at +15 shows gobs of 3rd, 5th, 7th, etc

Tube at +3dB shows a little 2nd

Tube at +10 shows some 2nd, a bit of 3rd

Tube at +15dB shows 2nd, a little 3rd, diminishing amounts of higher harmonics

What is important is that the cues the ear uses to establish loudness are based partly on the presence of the higher harmonics, which give the sound it's 'edge', and with enough of them sounds metallic, raspy, and harsh.

With SS you can only go a little into overdrive before these higher harmonics begin to dominate the sound and make it unlistenable.

With tubes you get to a higher SPL level before the 'edge effects' make their appearance in the sound. Not only does this allow for higher levels of musical enjoyment, but it also lends a natural dynamic compression that improves the signal to noise ratio - that is, because the loudest peak demands are louder, so are the softer sounds.

[maxg]

As usual Jeff you managed to start a thread that goes all over the place and back again.

OK - a few basics:

1. A Watt is a watt is a watt - from a tube amp - an SS amp or anything else (like your power supply).

2. Yes - there is a school of thought that says - if I have a big enough power amp then I will never have to worry about clipping. Your case is similar to that - you have a 104 db/w/m senstive speaker with a maximm continuous rating of 100 wpm and a peak of 400. Your amp is 330 - ish continuous and probably has a couple of db Headroom on top. You get get the same effect with a B&W 800 (91 dB) and a 1000 watt amp.

3. Whilst the logic of item 2 above stands - there is a question over that pesky first watt. How does it sound when playing quietly? Here is where tube amps often show benefits. You mentioned the most commonly cited distortion figure - THD or Total Harmonic Distortion. You noted that the figures for tube amps are much higher than they are for SS and no-one will deny that, but: THD is a figure generated at FULL POWER - or thereabouts. Full power is where Tubes are at their worst for distortion and SS is at its best. The interesting thing is that reverse is also often true. The SS amp shows its maximum distortion at very low power whilst a tube amp shows its lowest distortion.

In other words for item 3. If I have your speakers (say) and 2 amps - one a 300B 8 watt class A amp and the other your crown which will sound better when the volume levels are 95 dB (for example) at 1 meter?

Note : That is a rhetorical question - there is no correct answer - suffice to say that there are some that would choose the SET amp in a flash and others, probably, that would go for the SS amp.

Now as you approach the 8 watts continuous you may well find that the tube amp starts to clip - although that might be rather difficult to spot sonically. At this point one would expect the SS amp to start to sound, relatively, better to a greater proportion of the listeners than at the volume levels given above.

Of course 8 watts is 113 dB (at one meter). In a moderately sized living room that can be very loud. Nobody (that I know of - at least till the advent of digital amps) makes an 8 watt SS amp. Here is, I think, where the myth over the magical tube watt started.

Imagine someone who is not an expert hearing your speakers playing with 8 watts. They have never heard of an 8 watt amp before - all the SS amps they have heard of are 50-500 watts - yet here we have an 8 watt tube amp playing as loud as a B&W 802 with 300 watts.

Conclusion - tube watts are magic.

OK - that is an exaggerated example but most people think that if they have a 100 wpc amp and turn the volume to half way they are listening to 50 wpc. You arrive with an 8 watter - turn the volume to half way and get the same volume - magic again.

Any of this make any sense to you?

[Deang]

http://www.rocketroberts.com/techart/powerart_a.htm

[Colin]

This is an excellent article and I am glad to see him re-visit the subject.

"More than twice the voltage technically supposed possible! You'd need a 50 Watt transistor amp to realize the same peaks my 9 Watt 300B launched without wincing at my 'speakers! "

A transistor amplifier performs similarly into either a resistive or a real loudspeaker load. Externally augmenting its traditionally very low output impedance (high 'damping factor') to a value of 3.5 ohm as commonly found in non-feedback valve amps helps mimicking valve amp behaviour. Apparently, amplifiers that have 'ideal' near-zero output impedance waist energy that the loudspeaker has in store and is ready to use for building up extra sound pressure, by short-circuiting this energy out. <?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" />

The feedback issue as yet leads to further confusion. But feedback or non-feedback, most valve amps laugh in the face of the poor solid-state amp, even with the external 3.5 ohm applied.

So valves do something special transistors can't. But we already knew that, didn't we. [?]

So he is saying the very low output impedance (less than 4-ohms 'damping factor') of non-feedback tube amps doesnt waste energy the loudspeaker store for extra sound pressure?

Didnt his original article conclude that tube amplifiers pump out about 5 times more current than their RMS measurement reveals? Why not compare IHF measured wattage versus RMS measured wattage on tube and solid-state amplifiers? Bet that would also confuse things

Ditto Deano on the class T chip amplifiers

Mark, its the new millennium, cant we just plug everything into our cell phone or iPod and reduce the sound quality to a buzzing blather, then the amplifiers wont matter?

I cant see the occlusions on vs1 compared to vs2 without a 10X scope = Ill take the 5 carat diamond for my babe thank you, other women wont be able to see the occlusions without a loop, but they will see that rock a mile away!

Max, tubes arent magic? Then why do they cost so much?

[H]

[6foot8]

I have had both Khorns and la Scalas driven with both tube and SS and in my experience I was always on the edge of the sofa wanting more when I was using a tube amp. Impossible to get enough bottom end in a large room with a small amp (tube or SS). I no longer have the Khorns but I still have the La Scalas in another room and the improvement in bottom end was very noticeable with a very good SS amp..again BGW. These are very large amps with massive power supplies and are rated at least twice what the speakers will handle continuously. Some of my bigger BGWs are three times rated power of the La Scalas...they do not clip, or get close to running out of power...period and end of story. I also have the added benefit of more bottom end at reasonable listening levels in a large room. For my Jubilees I must have a very good SS amp for them as no tube amp in the world (that I know of) is going to give me a minimum of 400 watts continuous with 6dBs of headroom without costing more than my house and weighing in at 500lbs.