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lemme get this straight (wattage -> output volume)

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(the stuff on the left of "<" is quieter...)



solid state wattage < tube wattage

class AB < class A (but class AB goes up to higher wattages... never seen a 100W class a before...)


10w is actually half the volume of 100w...


and speakers make a bigger difference in volume than wattage. if plugged into the right speaker, a 20w amp can be louder than a 100w amp.






and higher wattages give more headroom... so less power tube distortion...




a friend of mine got a solid state 100w marshall halfstack, and i want to see if i can buy a peavy windsor studio (a 15-20w class a combo, depending on output tube. can use 6550's, el34's, 6L6's... kt66&88... has a single 12" speaker)

and go to the same gig he plays at.


might want an amp stand?



i was thinking... tungsol 12ax7, winged c 6550, jensen jet tornado speaker... (100w power handling, neodymium magnet... the clip on their site sounds pretty good to my ears...)






i probably wouldn't consider the windsor if the valve senior had a set release date...

but as it is, none of us even know if it will ever exist except in pictures....

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Watts aren't an accepted method to judge sound pressure level (SPL, AKA loudness, volume, etc.), they are simply a power output rating taken under some preprescribed conditions. To assess SPL, you must consider the sensitivity rating of the loudspeaker/cabinet, at what distance the measurement is taken (standard is one meter), what frequency is being used (1k, white noise, pink noise, etc.) and how much harmonic distortion is being allowed during the measurements.


If all other parts of the equation are equal and the measurements are performed under identical acoustical conditions, it takes rougly twice as much power to acheive 3dB more SPL. So a100 watt amp could provide an SPL increase of roughly 10 dB over the SPL level provided by a 10 watt amp. Whether that difference is perceived as "twice as loud" by the listener is entirely subjective.


As far as headroom, you are roughly correct, higher wattage means more clean volume before distortion, assuming the speakers/cabinet are designed to handle that power and SPL. Otherwise you will get speaker distortion and eventually fuse or break the voice coil - AKA blown speaker(s).


See the following for more info:





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Watts are watts, regardless of whether they are solid state or tube watts. brianh pretty much hit the nail on the head.


You will probably not be able to keep up, volume wise, with your friend because he is going to be playing through 4 12" speakers. His sound will be more dispersed.


If it is one of the MG series amps, I will almost guarantee you will sound better.

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I used to own a 100 watt Marshall AVT w/ 2x10 (or 2x12, I forget now). Anyway, I was always getting blown away by guys with 40 watt tube amps (class AB most likely) so I dumped the AVT and never looked back.


One thing about speakers, more speakers push more air and the preceived volume will be greater.


Another preceived volume boost you can do is get it up on an amp stand so it will be closer in line to your ears instead of your knees.



I agree 100% with the AVT comments. A very unfortunate amp choice.

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Efficient speakers and amps always blow away their cheaper counterparts. If amps are all rated at RMS levels, the clean wattage will be a closer measurement of useable volume. Tubes can approach distortion and still sound great, some sound even better, so you perceive this as louder. When you distort a SS output stage, the result is nasty, so you are limited in useable power output to the clean volume output of the SS amp.


OTOH, if your amp has a speaker that exhibits a hole in the freq response at some frequency, it will never produce the volume at a given wattage level as an amp that has a speaker with a smooth response curve. You can prove this by turning down the tone to 0 and up to ten on bass, mids, or treble and listen to the result. A tone control is a volume control for that band of frequencies, since it is a unity gain amp with a notch filter in real life terms. A speaker with a non-linear reponse is similar to a tone control turned down, so a cheap speaker will be lower in perceived output level.


The point here is that some amps and speaker combinations are just more efficient than others. More speakers move more air, assuming that you have the power to drive the voice coils efficiently.

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Watts are watts' date=' regardless of whether they are solid state or tube watts. brianh pretty much hit the nail on the head.


You will probably not be able to keep up, volume wise, with your friend because he is going to be playing through 4 12" speakers. His sound will be more dispersed.


If it is one of the MG series amps, I will almost guarantee you will sound better.[/quote']



i already sound better with my firefly... i've been using a blackstar ht dist pedal...


he does lots of ac/dc type stuff, and everybody he gigs with has some solid state 100w marshall halfstack or another...



i've been told repeatedly "solid state watts ? tube watts" and "class ab 20w < class a 20w"

but i guess... w/e.


i just want to show those guys what "all tube" sounds like, and do it at their volume. i want them to think second thoughts about their amp choices... (seriously, i was talking to one of them, and when i mentioned tube amplifiers, he said he wasn't rich... so i told him that he could have gotten a 100w peavy windsor halfstack for less than his marshall... less than just the marshall head even... but by then he didn't care to listen. they see their idols, zakk wylde and angus young... with the name marshall behind them.)

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i've been told repeatedly "solid state watts ? tube watts"


I think I know where this comes from. First off, RMS ratings are sorta BS anyway. They're fairly arbitrary. HOWEVER, the way that amps are rated for output IS standard, so the arbitrary ratings are the same for all amps, which means that the numbers at least have SOME relevance to us. If we have experience with a 5 watt tube amp and a 50 watt tube amp, for instance, we can make a reasonable assumption as to what kind of useable output a 20 watt amp would have, right? RMS ratings are taken BEFORE distortion, which is why it's such an arbitrary number, since you're sort of guessing at when distortion begins...unless the distortion is particularly harsh or significant, it's very difficult to see it on a scope.


This misnomer that SS watts are less than tube watts came, I believe, from the fact that tube amps can push far more output than their published rating. It's not unreasonable to assume that an 18 watt Marshall, pushed to distortion, is actually putting out more like 25 or more watts, and if you use a boost pedal, even more yet. Some tube amps can push nearly TWICE the RMS rating, when overdriven. The question becomes, where do you measure output?


With a tube amp, and particularly when a guitar is plugged into it, this distortion is something that is generally found favorable, and a goal to attain. With a SS amp, however, pushing the amp beyond it's limits is harsh and ugly, so it's avoided.


Thus, you can have a 20 watt tube amp that's capable of pushing perhaps 30-35 watts, and a 20 watt SS amp that's going to push very little more than 20 watts.


The belief that tube watts is more than SS watts really stems from the fact that RMS ratings don't take into account what happens to a tube amp that's overdriven. There probably should be two different ratings...one for SS and one for tubes, because that would give a person a more realistic comparison. However, since not everybody pushes tube amps to the point of distortion, that too, would be an arbitrary number, wouldn't it?


and "class ab 20w < class a 20w"

I'm not sure where this one comes from, to be honest. You can certainly make the comparison in tube amp vs. tube amp, so there needed be the sort of lopsided comparison that you'd have between tube and SS. I really can't think of why there would be this belief, to be honest.


Perhaps, it's got something to do with the way that the two amps distort, and the fact that class A will push more even order harmonics, vs. AB, which pushes more odd. There's undoubtedly a difference in the harmonics content between the two.


I think that, oftentimes, these statements are probably made based on false comparisons. Somebody cranks an AC30 loaded with hyper-efficient blues and compares it to a cranked Fender, of similar output but with very inefficient speakers, and concludes that the "class A" Vox is putting out more power. If they were to run both amps into the same type of speaker, they'd probably have a different conclusion. Speakers and cabinets make a HUGE difference in perceived output.

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m-theory, I completely agree with you. Amp ratings are subjective when it comes to a side by side comparison. Ever since Mr. Randall put a 12" speaker and 100 watt Fender Bassman electronics into a Princeton cabinet and created the first Mesa Boogie, people have been judging amps by tone and loudness. If you build a better amp, people will beat a path to your door, until someone else adds something attractive and creates the next "gotta have it" gadget.


Amps and speakers are a little like got rod cars. Do you measure it by horsepower, 1/4 mile times, or top speed? Just because your car will do a wheelie doesn't mean it will run faster in a mile than mine.


The final test of an amp is performance in the application in which it must live. If it sounds good in the bedroom, will it sound good outside on a stage surrounded by concrete walls in a parking lot? Will it be loud enough? Will it hurt your ears when you crank it to 10 or will it get sweet and full of sustain? Can you play in a small club and crank it to the sweet spot or will the club owner run you out? All of these tests will determine whether you need 20 watts, 40 watts, or 100 watts. If it's SS you probably need to buy more wattage than a tube version of the same size due to whether you can overdrive it or need to back it off to stay sweet and clean.


And there's the personal factor. I wouldn't have some amps because my ears hear differently than others. If you listen to guitar players using the same amp, you will hear vastly different setups and tonal variations when they dial in "their tone". One of the best guitar tones I've heard in an outside venue was a band that was set up on a stage on Fremont St. in Las Vegas last October. The lead guitar player had kind of a Golden Earing sound and outside it was full, ringing, powerful, and pleasing. He was playing through a 4x12 Marshall mic'ed into a large PA. When he slid down the neck on the 6th it sounded like a jet taking off! Frequently, I will sit and listen to guitar players playing through a Marshall stack and think "I'd cut the highs about 4 clicks and get rid of that chinky sound". It's all relative.

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