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Why Do Tube Amps Sound Louder Than Solid State Amps?

January 20, 2012 on 2:46 pm | In General, Guitar, Tech | 1 Comment

It’s a common belief among guitarists that tube amps are louder than solid state amps. I’ve seen little 30 watt tube amps blow away ginormous 100 watt solid state amps. This is not a myth, it’s a fact. Here’s why.

First, it must be pointed out that watts are watts. Tube wattage is not different from solid state wattage. It’s simply ohm’s law.

W = I2 x R

By any objective measure, 50 watts from a tube amp is identical to 50 watts from a solid state.

So why do tube amps sound louder?

It comes down to two things. How the wattage of amps are rated and how tube amps clip/distort differently from solid state amps.

An amplifier’s wattage rating is not a measurement of its maximum output. The wattage of an amplifier is rated at its highest output without clipping.*

Here’s a picture to show what clipping is:

As the wattage is increased, the amplifier reaches a threshold where the highest outputs are clipped off. This clipping causes distortion. In a PA system, it would suck. In a bass amp this would suck. But guitar players use this clipping to modify and add to their sound.

The next part of the puzzle is this: tube amps clip different than solid state amps.

Tube amps clip gradually as the wattage is increased while solid state amps remain clean until they’re suddenly very clipped/distorted.

The gradual clipping of a tube amp adds to the flavor of a guitar. A guitar player using a tube amp can play harder to get more clipping and play softer to play smoother. These subtle nuances add character to a player’s sound. The sudden massive clipping of a solid state simply sounds like shit. There are no subtle clipping nuances with a solid state amp, it’s either not clipped or fully clipped.

Based on the foregoing, manufacturers of solid state amps set their volume knobs to nearly 10 before the clipping starts. So to get a 50 watt solid state to full wattage, you have to turn it up nearly all the way.

Manufactures of tube amps know that guitar players want clipping, so they take that into consideration when they set their volume knobs. So a tube amp reaches its maximum wattage at a much lower volume setting. Probably 3/4 of the way up. Sure it’s clipping past that point, but it’s a warm and good sounding clipping.

So if you turn up a solid state and a tube amp to 10, the solid state is pushing its full 50 watts, and probably sounds like shit because that bad clipping would be starting (unless its a very high quality solid state amp such as a Fender or a Roland**). while the tube amp would be pushing more than 50 watts. The tube amp would be clipping, but it would be that good sounding clipping.

And of course a 50 watt tube amp set to 5 is putting out more watts than a 50 watt solid state amp set to 5.

I should point out that I’m not arguing that tube amps are “better” than solid state amps. I’ve owned plenty of solid state amps in my life and only a few tube amps. And furthermore, objectively speaking, solid state amps are cleaner and are less prone to clipping. However, subjectively people like the sound and warmth of tube amps more, despite their objective faults. Well, that’s not right. People like the sound and warmth of tube amps more because of those faults.

*This is how the wattage of quality amplifiers are rated. Measuring the maximum output including clipping is one way how low-quality amplifier manufacturer’s cheat. Another way they cheat is by measuring the peak and not the average (RMS) wattage. Thus you can find 2000 watt amplifiers for only 77 bucks on Amazon. If it sounds too good to be true, it probably is.

** Speaking of high quality solid state amplifiers, back in the early 90s I used a Fender Princeton Chorus. It was only 50 watts, but it rocked. Actually, it was even less than 50 watts. It was actually two 25 watt amplifiers in stereo. So basically I was playing through two 25 watt amps each into its own 10″ speaker.

But it was loud. Not as loud as the singer’s tube Fender Twin (which I think was rated at 25 watts), but plenty loud enough. I never had any problems at any show we played.

Generally speaking, the vast majority of tube amps are of a high quality. There simply is not a market for low quality tube amps.

However, the vast majority of solid state amps sold are of a lower quality. A 25 watt Crate solid state from the 80s would never have been loud enough to play in a band. I know because I used an 80′s built 75 watt Crate 2×12 combo in the early 90s and it was not loud enough. (Luckily some one gave it to me for free.)

So if two guitar players are in a room, one with a tube amp and one with a solid state amp, statistically speaking, the tube amp is going to be of a much higher quality than the solid state. As I explained above, that’s going make the differences in volume much more apparent.

However, if the solid state was a Fender or a Roland, there would be no discussion of, “Why is your little amp so much louder than mine?”