Tube vs. Solid State Power Rating

[86mod5]

I was going through some recent Guitar World mags and came across a columnist who said that a 100-watt tube amp was equivalent to a 300-watt solid state amp in terms of volume. So basically, there is a 1:3 ratio between the two when it comes to volume. I thought a watt was a watt no matta watt. Has anyone here done a side by side comparison to this effect? Is this true?

[Cleveland Metal]

Re: Tube vs. Solid State Power Rating

I've always felt it was more like "percieved" volume. Tube amps just seems to project better.

Basically, when tube amps get overdriven, they really display the second, third, fourth, and fifth harmonic overtones which give a full quality to the sound. The further it is driven into saturation, the higher harmonics like the seventh, eighth, ninth, etc increase in volume. These add a lot of edge to the sound which the ear translates to loudness.

[86mod5]

Re: Tube vs. Solid State Power Rating

I don't doubt what you're saying, but there appears to be a tremendous power difference between 100 and 300 watts that I would think the Solid State amp would have to be noticeably louder.

[Cleveland Metal]

Re: Tube vs. Solid State Power Rating

Well, I'm not sure what the ratio is, but although you might figure it would be 3 times louder, that isn't the case at all. If you double the wattage in any amp, the volume increase is noticeably just a bit louder.

I notice it is quite common for solid state guitar amps to be around 300 watts and common for tube units to be 100 to 120 watts, so, I'll figure there's a reason for the general difference.

I may be wrong here, but being that the solid state amps are more linear and flat in response, they spend a lot of energy reproducing all frequencies evenly in the stated range, and the tube amps are less linear and spend their energy on a more focused range frequencies (that we tend to hear better). Hence, they may use the wattage more efficiently for our ears purpose.

You can see the volume vs frequency thing a bit when you see a band that scoops their mids really heavy (death metal etc), they may move so much volume that you feel it and your head hurts even, yet you can't quite hear the guitarist very well. The mids, are missing and the sound doesn't cut as well. Although it IS VERY loud nd the wattage is there, you still don't hear it as well. It's just that they are using a frequency range that the ears don't notice as much I guess.

You could blast thousands of watts in a frequency we don't hear so well, and a 100 watts in a frequency we do, and the 100 watt freqs will be what we hear.

It's not that the solid state is "bad" and tubes are "good" they are just different, and it's just the physical characteristics of how they reproduce material in relation to how our ears can hear it.

Myself, I like tubes, but solid state has uses too.

I hope I made sense, haha...

[charvel750]

Re: Tube vs. Solid State Power Rating

The 3:1 ratio is untrue. A 50 watt amp is not 1/2 the output volume of a 100 watt amp. A watt is a watt till the cows come home. I used tube heads for a long while (Marshall, Boogie, VHT, Bogner) but nothing beats the stereo spread of a vintage Roland Jazz Chorus. That is a tone to die for if you know how to use the amp right.

[Cleveland Metal]

Re: Tube vs. Solid State Power Rating

A watt may be a watt, but a 100 watt tube amp will be percieved louder than a 100 watt solid state amp. Yet, they are using the same energy, (actually the tube amp uses a lot more energy to put out the same wattage as a solid state, hence it is sorta less efficient in producing the wattage), we just perceive the freqs that a tube amp favors to be more loud, that's all.

And in this discussion, tone isn't the focus.

[lantz_c]

Re: Tube vs. Solid State Power Rating

[ QUOTE ]

I notice it is quite common for solid state guitar amps to be around 300 watts and common for tube units to be 100 to 120 watts, so, I'll figure there's a reason for the general difference.

[/ QUOTE ]

I always figured the reason for that was so solid state amps would have enough headroom to be used at live volumes without getting too fizzy sounding. That's just a guess though.

[Ozz666]

Re: Tube vs. Solid State Power Rating

There is definitely not a direct correlation like a 1:3 ratio in volume difference...it's really dependent on a multitude of factors and each amp is different. What I will say is a 60 watt tube amp will be louder than a 100W SS amp. But don't get hung up on how loud something will get...that's not the point...a 60 watt tube amp will blow your ears off. The higher watt rating is more important if you plan on driving multiple speaker cabs and need more headroom. I've got an Engl 60 W head that I drive a full stack (2 Mesa 4x12's) with and it will blow you away if you play past 12 o'clock.
I've posted before (maybe a year and a half to 2 years ago) the forumla to calculate the sound intensity (Loudness) in dB. Using the formulas a 100W amp was only 8 or so dB louder than a 50W....

Final word.....a 100W amp WILL NOT be 50% louder than a 50W amp. Here's the forumla in case you wanna see for yourself...

The loudness level of a sound, d, in decibels, is given by

where I is the intensity of the sound and Io is the intensity of a sound barely audible to the human ear. Io=10^-12(W/m^2)

- Joel

[sevser]

Re: Tube vs. Solid State Power Rating

Charvel750 said "The 3:1 ratio is untrue. A 50 watt amp is not 1/2 the output volume of a 100 watt amp."

Did someone say a 50 watt amp was 1/2 the volume as a 100 watt amp. And the 3:1 ratio was a SS Vs Tube comparison.

I did read this though and it seems to be stating the same thing you did...

CM said "If you double the wattage in any amp, the volume increase is noticeably just a bit louder."

[Outlander]

Re: Tube vs. Solid State Power Rating

more food for thought....
There also appears to be a big differance between manufacturers ideas of watt ratings, for instance two differant brand tube amps of the same rated wattage with the same speakers will usually have a noticable differance in perceived volume.
It seems Mesa rates their conservatively while some others rate theirs more aggresively than what they sound like. just an observation.

[catzodellamarina]

Re: Tube vs. Solid State Power Rating

The only real-life comparison I've had was when I owned 2 poweramps back to back: an ADA Microfet 100 (50-50) and then I bought a Peavey Classic 50/50 tube amp. The tube Peavey seemed louder and I could finally hear myself over the other guy who had a Laney or KMD tube head. I never went back to solid state for live rigs after that.

[DonP]

Re: Tube vs. Solid State Power Rating

This is some-watt true (LOL!). When a transistor amp hits it max rated power, it hits a solid ceiling and can get not louder. It just clips the signal harder.

Tube amps can go over there ceiling. They don't clip hard, they just start rounding off the peaks of the signal. A 100 watt Marshall is rated 100 watts at no clip. It can get up to 125, but with major distortion going on.

To simplify Joel's formula, in order to double the loudness, you need to increase power by a factor of ten. A 100 watt amp is twice as loud as a 10 watt amp. Go check out a small 15 watt amp like a Blues Jr. Pretty damn loud. And play fair - a 1x12 won't be as loud as a 4x12. Both amps you are comparing should be allowed to drive the same speaker load.

One other big factor is the output transformer. Guitar amps come with trannies that are 1/2 the size of a tranny rated for high-fi. Chuck in an output tranny twice the current size of what is in your 100 watt Marshall and your eardrums will bleed from the huge bass response. It will have more power in the lower end where you feel it.

[iron_monkey]

Re: Tube vs. Solid State Power Rating

Loudness really depends on the distortion you are going to allow. Are you going to compare amps only in the linear range of their output?

Clip a signal enough and you start to get a square wave which has a much higher crest factor than a sine wave. Different amps will handle the square wave better or worse depending on the transformer.

Also, are you comparing the amps with the same speakers? Speaker efficiency can make a difference.