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Asher Guitars WD Music Products Amplified Parts Mod Kits DIY Nordstarnd Pickups

Watts tube vs. Solid State

Discussion in 'Amp Central Station' started by Anwar, May 15, 2011.

  1. Anwar

    Anwar Tele-Meister

    Nov 29, 2009
    Whats up with the discrepancy between tube amp wattage and solid state wattage as compared to actual loudness? I mean if you got a 10 watt solid state it may be too soft to practice at home in your room....with the door closed. If you got a 10 watt tube amp maybe it will be great for BAND PRACTICE...with a hard hitting drummer in a small club. How could that be? Did all the manufacturers just collectively decide to mislabel their products?

  2. scantron81

    scantron81 Tele-Afflicted

    Apr 29, 2009
    I'm just gonna sit back with a bag of popcorn and watch this thread grow grow grooooow. :)

  3. Chase TM

    Chase TM Tele-Meister

    May 11, 2011
    Toronto, Canada
    My 22 watt deluxe reverb and 120 watt henricksen both deliver equally. i'm not saying they are the same volume, but I've never really hit the ceiling with either of them on jazz gigs.

  4. BigDaddyLH

    BigDaddyLH Telefied Ad Free Member

    I don't know, but i wonder if SS amps are taken to the limit, where their distortion sounds nasty, while tube amps have a smoother distortion at the limits that's more musical.

    Acoustic Image, for example, has a standard SS amp head that's 800watts. That's an amp for jazz guys! A 800watt tube amp would lay waste to the countryside.

  5. Northerntele

    Northerntele Tele-Holic

    Sep 30, 2010
    New Orleans
    100 watt solid state Fender stage lead = enough volume for medium bar. maybe

    100 watt tube (allegedly, in reality its more like 120) Ampeg V4 = right volume for smallish stadium.

    That said I don't have a clue why they are rated the same.

  6. scantron81

    scantron81 Tele-Afflicted

    Apr 29, 2009
    I've heard the 4:1 ratio thrown out a lot over the years. I've also seen a lot of guys scoff at the notion and pull out wild theories about sound waves, ear canals, brain functions, etc. I haven't seen any hard evidence to the numbers but it sounds about right. In theory, a tube amp is 4 times as loud as its solid state counterpart of equal wattage. So, it would take a 40 watt solid state amp to equal the power of a 10 watt tube amp.

  7. Anwar

    Anwar Tele-Meister

    Nov 29, 2009
    Yeah, who ever thought of playing a 1 watt solid state amp to practice with. What would that be for in solid state terminology....headphones?

    Are the watts actually the same? Perhaps they mean average watts and tubes have louder louds and softer softs? That would mean SS is just more compressed? Why would they just B.S. us like this? It sounds like misleading B.S.

  8. jazztele

    jazztele Poster Extraordinaire

    Sep 19, 2006
    Well, I'm no expert, but I think the problem is people equate watts with volume (db)

    Watts are only concerned with power. How the amp uses that power is what results in volume...

    Am I close? Where's johnnycrash when you need him?

  9. RomanS

    RomanS Poster Extraordinaire

    Jun 21, 2006
    Vienna, Austria
    Solid state amps sound nasty when they are cranked so they distort - and that distortion sets in rather abruptly once you go above a certain point; you won't like the sound they produce above their rated output...
    Tube guitar amps, on the other hand have a much smoother transition between their "clean" (which is actually never really clean by hi-fi standards, anyway) and overdriven settings, and tube distortion is much more pleasing to the ear, so you might already be running your tube amp at a much higher wattage than it is rated at before you notice any distortion at all!

  10. Jimmy Dean

    Jimmy Dean Tele-Afflicted

    Back in the 80's I had a Roland JC120 head w/212 cab. I bought a Carvin 30w 112 tube combo & it was as loud as the JC. I have always wondered why?

  11. jh45gun

    jh45gun Banned

    Jan 20, 2006
    Northern WI Gods Country!
    A lot of SS amps are way over rated wattage wise. Especially car stereo stuff. Though I suspect SS guitar amps with some of the cheaper amps are over rated to get customers roped in to buying them. Better quality SS amps made by good companies are probably close but still my 100 watt tube amp will make your ears hurt my 80 watt bandit does not come close. My ten Watt MMB amp will out perform a lot of so called 40 watt SS amps.

  12. tele salivas

    tele salivas Poster Extraordinaire

    Sep 5, 2008
    My stock 50 watt SS Laney puts out a bit more than my stock 15 watt Princeton Reverb RI. I believe part of that is due to a 12" speaker vs a 10" speaker and the way it distributes the sound.

  13. jondanger

    jondanger Friend of Leo's

    Jan 27, 2011
    Charm City, MD
    The way I understand it, the power rating (wattage) is the same in solid state and tube amps, but tube amps have a wider usable range of power. Solid state amps sound bad when they distort, so the headroom is lower. You can't turn up a 100 watt solid state amp to the maximum of its range and produce a usable sound. Tube amplifiers add more desirable harmonics and distort in a way that is more pleasing to the ear, so the usable range of their power is greater. This doesn't mean that they are more powerful, just that they don't crap out when you push 'em.

    I now realize that this is basically exactly what Roman said.

  14. celeste

    celeste Friend of Leo's

    Jun 24, 2006
    The answer has its roots in Federal regulation. to be specific, the FTC stepped in in the 70's and mandated how audio amplifiers would be rated for power. In the HiFi world this was a good thing, in the musical instrument world, it causes confusion.

    the problem is now power is rated at a rather low THD, something like under 5%. Most amps can put out more power, it is just that distortion goes up with power and the law does not allow you to claim power above that distortion level. In the case of a well designed tube amp, clean is likely about that 5% THD, and you want over drive, you can push THD over 10% and power much higher then you can legally claim. In the case of a SS amp, the distortion they produce is mostly odd order and due to much higher feedback levels, much higher order. All things that are unpleasent to the ear. So you end up never really cranking a SS amp the way you do a tube amp.

  15. printer2

    printer2 Poster Extraordinaire

    May 24, 2010
    If you took two 100W amps, one tube and one solid state, ran them clean up to their rated power they would sound equally loud. Put a scope on the output and with a sine wave adjust the gain so they put out 100W into 8 ohms, both would be putting out 28 volts RMS.

    Now take a distortion pedal, clip the hell out of your guitar and feed it into both of the amps. As long as you put the same signal into either amp and you do not go over 28V they will be equally loud.

    So why does a tube amp sound louder to everyone? As said above, taken into distortion they are more pleasing to the ear. Can a SS amp be designed to overload in the same manner as a tube amp? Some say they can but it is not cheap and easy to do. Much easier to just add more power and keep it out of the harsh distortion.

    Many years ago I had a solid state amp of about the same wattage of a tube amp and it played as loud as the tube amp. Mind you the guitarist wanted something buzz saw sounding, no finesse in the sound. The interesting thing was that the transformer was undersized in current for the voltage the amp ran at. In other words on clean signals the power supply was lightly loaded as the peaks were high in level but the average signal level was not. When he cranked it the power supply sagged just like a tube amp. With a stiffer power supply it could have been rated as a 30 watt amp rather than a 20 watt.

    So clean the amp had more headroom than its power rating suggested. Distorted it had the same loudness as a tube amp had as long as you were happy with the sound.

    Now if you scoped a tube amp and found that it put out 35 volt peaks and clipped at 25 volts under heavy load you could design a solid state amp that could sound the same but you would have to cheat a little. First you would have to add 10% to the power output under both conditions. Then you would have to reproduce a pleasing distortion characteristic to simulate a tube amp distorting, either by a fancy stomp box or do it with a digital processor. Then your transistor amp will sound as loud as a tube amp (giving it the 10% advantage).

    Really a watt is a watt tube or SS. What you do to the signal before it leaves the amp is what determines how loud you crank it. A SS amp can be just as loud as a tube amp. As long as you do not mind the sound.

  16. printer2

    printer2 Poster Extraordinaire

    May 24, 2010
    With SS amps there is a lot of negative feedback and it keeps the output clean right up to the point where the amp runs out of voltage and clips the signal. No mater how much more signal you put in you will not get any more voltage out.

    Tube amps do not have as much negative feedback as a SS amp because the stages are capacitive coupled and they have that transformer in the back end throwing in a lot of phase shifts. With a lot of negative feedback that phase shift causes positive feedback and you have a squealing pig. So rather than the tube amp putting out clean power till it runs out of supply voltage you get the tubes acting nonlinear as they get closer to their limit.

    So rather than like a SS amp where the distortion curve is low and then goes straight up when it clips a tube amp distortion curve looks more like a hockey stick. It increases but the amp can still put out more voltage (power) before it clips. It might be putting out 10% or 20% distortion but it is not like that will bother us. :D

    You could have a tube amp that runs out of steam once it hits its rated power, it all depending on how the manufacturer designed the amp. Some tube amps sound louder than others even though they are rated for the same power. This power thing is not black and white.

    Oh I forgot to add, the SS amps are more odd order but it is the higher order harmonics that are the problem. If they only had a lot of lower harmonics they would sound like our P-P amps.

  17. muchxs

    muchxs Doctor of Teleocity

    Aug 14, 2004
    New England
    I run into something similar with tube wattage. 18 watts doesn't seem like a lot. Might as well go with 30. Well... there's no practical difference between a properly built 30 watter and a properly built 50 watter. Trust me on this! You won't be able to crank either of them into their sweet spot for many gigs. It's one thing when club owners tell you to turn down, it's quite another thing when the drummer tells you to turn down... :rolleyes:

    Next step down is 12 to 18 watt amps. Club owners will still tell you to turn down...

    Then there's the hassle of getting clean headroom under ten watts. Actually there's clean headroom at a fraction of a watt as long as it's a fraction of a watt with 20 more watts to spare. Almost no one seems to understand that... :rolleyes:

    Last comment: A small tube amp built like a big tube amp will act like a big tube amp.

  18. Anwar

    Anwar Tele-Meister

    Nov 29, 2009
    Ah thanks everybody! In other words both being equal in rated wattage the tube amp sounds better ABOVE the wattage rating than the solid state ones do. So the idea of 1 watt tube = 4 watts solid state has credence. A 5 watt tube amp might be operating at 10 watts in order to get the tube overdrive crunch sound.. A 20 watt solid state might be operating at 10 watts in order to avoid distortion and get the crunch out of a pedal.

    So that means a 5 Watt class A tube amp has the same practical loudness factor as a 20 watt solid state amp when played for a slight crunch sound.
    Last edited: May 16, 2011

  19. Steve G

    Steve G Friend of Leo's

    Nov 3, 2005
    LeeK (England)
    This question also makes me wonder how they accurately rate speaker power handling when there is this large discrepancy in volume from one amp type to another.

  20. jh45gun

    jh45gun Banned

    Jan 20, 2006
    Northern WI Gods Country!
    Speakers make a difference I took the Fender Speaker out of my MMB and put in a Eminence speaker that blows away the factory Fender speaker in bottom end and added head room.

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