RogerMexiko
New member
Is there some different criteria used in measuring tube and SS amps? Or is my 20W amp just broken?
why is a 5W tube amp louder than a 20W SS amp
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Little Pigbacon
Guest
Re: why is a 5W tube amp louder than a 20W SS amp
It's awfully tempting to think that the same signal being run into the same speaker at 20W would be louder than the same thing done at 5W. That said, tube amps usually sound better when they're starting to run out of power than SS amps do. A solid-state amp might abruptly become sonically unviable at a certain level, while the tube amp, despite climbing distortion, might be perceived as having quite a bit of travel left on the volume control.
It's awfully tempting to think that the same signal being run into the same speaker at 20W would be louder than the same thing done at 5W. That said, tube amps usually sound better when they're starting to run out of power than SS amps do. A solid-state amp might abruptly become sonically unviable at a certain level, while the tube amp, despite climbing distortion, might be perceived as having quite a bit of travel left on the volume control.
Myaccount876
Amira-Maker
Re: why is a 5W tube amp louder than a 20W SS amp
It's not that simple.
First - speaker efficiency. A more efficient speaker will be louder. Second - EQ. We do not hear frequencies "flat". Our hearing is most sensitive from 1kHz - 4kHz. For example, 100 Hz at 60 dB has the same *percieved* loudness (NOT the same amplitude) as 4kHz at 40 dB. This curve changes with loudness, and is flatter at higher dB ratings. An amp producing more upper midrange frequencies will sound much louder compared to an amplifier with the same exact amplitude amplifying just low frequencies. Also, keep in mind that the decibel scale is *logarithmic* - 60dB is not "167% the loudness of 40 dB", and there is a huge difference between 110 dB and 100 dB, because (again) it is a logarithmic scale. Third - RMS wattage. A 5w tube amp means 5 watts of clean headroom. If you're getting a clipping power section on a tube amp, then you're exceeding the RMS power rating (you're getting more than 5 watts). Usually solid state amps aren't supposed to clip in the power section because most guitarists think that sounds bad, so you generally do not exceed the RMS power rating on solid state amps.
Combine all these factors together, and then you realize that wattage is only a rough indicator of clean volume at best, and meaningless at worst.
It's not that simple.
First - speaker efficiency. A more efficient speaker will be louder. Second - EQ. We do not hear frequencies "flat". Our hearing is most sensitive from 1kHz - 4kHz. For example, 100 Hz at 60 dB has the same *percieved* loudness (NOT the same amplitude) as 4kHz at 40 dB. This curve changes with loudness, and is flatter at higher dB ratings. An amp producing more upper midrange frequencies will sound much louder compared to an amplifier with the same exact amplitude amplifying just low frequencies. Also, keep in mind that the decibel scale is *logarithmic* - 60dB is not "167% the loudness of 40 dB", and there is a huge difference between 110 dB and 100 dB, because (again) it is a logarithmic scale. Third - RMS wattage. A 5w tube amp means 5 watts of clean headroom. If you're getting a clipping power section on a tube amp, then you're exceeding the RMS power rating (you're getting more than 5 watts). Usually solid state amps aren't supposed to clip in the power section because most guitarists think that sounds bad, so you generally do not exceed the RMS power rating on solid state amps.
Combine all these factors together, and then you realize that wattage is only a rough indicator of clean volume at best, and meaningless at worst.
JBGenthner
New member
Re: why is a 5W tube amp louder than a 20W SS amp
Watts are like horsepower in cars. In the 60's horsepower was real. The record 0-60 time had been 2.9 seconds, made by a 1961 Pontiac Catalina 2+2, until the Bugatti Veyron came through with 2.5 seconds. So in a 2 ton car with supposedly 300 to 400hp, you did 2.9, and in a 3500 lb car with 1000hp you do 2.5. Something is wrong there.
So in the 60's when the Rolling Stones played stadiums, and Bill Wyman had a 200Watt bass amp that filled the venue, and today they have 15000-30000 watt SS PA systems to do the same thing, you just have to question the actual meaning of Watts between then and now
Watts are like horsepower in cars. In the 60's horsepower was real. The record 0-60 time had been 2.9 seconds, made by a 1961 Pontiac Catalina 2+2, until the Bugatti Veyron came through with 2.5 seconds. So in a 2 ton car with supposedly 300 to 400hp, you did 2.9, and in a 3500 lb car with 1000hp you do 2.5. Something is wrong there.
So in the 60's when the Rolling Stones played stadiums, and Bill Wyman had a 200Watt bass amp that filled the venue, and today they have 15000-30000 watt SS PA systems to do the same thing, you just have to question the actual meaning of Watts between then and now
Myaccount876
Amira-Maker
Re: why is a 5W tube amp louder than a 20W SS amp
The 2+2 was 3.9 seconds. That's still fast as hell even by today's standards, but a second is a big difference. Interesting comparison though, as horsepower is the (imperial) measurement of mechanical power, while wattage is the (SI) measurement of electrical power, and both can be misleading. In the case of the Veyron, only a fraction of the advertised horsepower is needed to accelerate that fast - the hundreds of excess horsepower is needed to reach its top speed of just over 250 mph because buoyant forces (like air resistance) are so great that a lot of power is needed just to overcome resistant forces. What you'd need for acceleration is torque - physical displacement of an object using applied force, and friction to prevent the wheels from slipping which would prevent all of the torque at the wheels from being transferred to the ground - moving the car. More force (force is not equivalent to horsepower), the faster the acceleration. That's why the 2+2 and Veyron look so wrong when just taking into account the weight and power, but make perfect sense when all factors are considered. Same with perceived volume and wattage - the results usually don't make sense when just looking at two measurements, but make absolute sense when all factors are considered.
The 2+2 was 3.9 seconds. That's still fast as hell even by today's standards, but a second is a big difference. Interesting comparison though, as horsepower is the (imperial) measurement of mechanical power, while wattage is the (SI) measurement of electrical power, and both can be misleading. In the case of the Veyron, only a fraction of the advertised horsepower is needed to accelerate that fast - the hundreds of excess horsepower is needed to reach its top speed of just over 250 mph because buoyant forces (like air resistance) are so great that a lot of power is needed just to overcome resistant forces. What you'd need for acceleration is torque - physical displacement of an object using applied force, and friction to prevent the wheels from slipping which would prevent all of the torque at the wheels from being transferred to the ground - moving the car. More force (force is not equivalent to horsepower), the faster the acceleration. That's why the 2+2 and Veyron look so wrong when just taking into account the weight and power, but make perfect sense when all factors are considered. Same with perceived volume and wattage - the results usually don't make sense when just looking at two measurements, but make absolute sense when all factors are considered.
devastone
Well-known member
Re: why is a 5W tube amp louder than a 20W SS amp
As was mentioned, the 5W tube amp is probably rated in RMS power (so it's max peak is probably ~7W), but I would guess a 20W SS amp is probably rated as peak power so it's RMS power is probably ~14W. It takes 2X the power to make 3dB difference, which is considered a barely perceptible audible difference. Also, you can push tubes harder and they compress nicely when pushed hard, SS just craps out when you get near the limits. So, when you factor all this in, the difference is probably not noticeable, and the tube amp probably sounds much better at the louder volumes than the SS amp (if it is getting near its limits). I don't mind SS amps, there are some decent ones out there, you just never want to run them near their limits, where with tubes, pushing them is good.
FWIW, 1W = 1W, there is no such thing as "solid-state watts" and "tube watts".
As was mentioned, the 5W tube amp is probably rated in RMS power (so it's max peak is probably ~7W), but I would guess a 20W SS amp is probably rated as peak power so it's RMS power is probably ~14W. It takes 2X the power to make 3dB difference, which is considered a barely perceptible audible difference. Also, you can push tubes harder and they compress nicely when pushed hard, SS just craps out when you get near the limits. So, when you factor all this in, the difference is probably not noticeable, and the tube amp probably sounds much better at the louder volumes than the SS amp (if it is getting near its limits). I don't mind SS amps, there are some decent ones out there, you just never want to run them near their limits, where with tubes, pushing them is good.
FWIW, 1W = 1W, there is no such thing as "solid-state watts" and "tube watts".
Lake Placid Blues
New member
Re: why is a 5W tube amp louder than a 20W SS amp
Tubes operate on high voltages and low current while SS operates on low voltages. It's the voltage available that becomes the main limiting factor once it runs out of 100% clean head room. Since the peaks with the high voltage tubes become just a bit rounded off and the wave form just slightly compressed, instead of cut off, it is significantly louder.
Tubes operate on high voltages and low current while SS operates on low voltages. It's the voltage available that becomes the main limiting factor once it runs out of 100% clean head room. Since the peaks with the high voltage tubes become just a bit rounded off and the wave form just slightly compressed, instead of cut off, it is significantly louder.
JBGenthner
New member
Re: why is a 5W tube amp louder than a 20W SS amp
Just FYI, a 1961 aluminum bodied Catalina 2+2 with an experimental 421 motor did do 2.9 seconds, with a Powerglide transmission, which is the closest you can get to a constant force, (almost no wheelspin), trans. The 421 option for regular people was added in 1962, without aluminum body panels. Still a 421 has less torque than a 16 cylinder 488 ci motor, just based on cubic inches and rotating mass, and I was wrong about the weight of the Veyron, and probably low on the weight of the Pontiac?... PLUS the Pontiac was on 1961 tires!, which is a whole nother story. Please pardon my senility... But that's neither here or there, as the rest of the info is right on.
I like the RMS vs peak comment, that's probably the original guy's answer.
Respectfully submitted,
Just FYI, a 1961 aluminum bodied Catalina 2+2 with an experimental 421 motor did do 2.9 seconds, with a Powerglide transmission, which is the closest you can get to a constant force, (almost no wheelspin), trans. The 421 option for regular people was added in 1962, without aluminum body panels. Still a 421 has less torque than a 16 cylinder 488 ci motor, just based on cubic inches and rotating mass, and I was wrong about the weight of the Veyron, and probably low on the weight of the Pontiac?... PLUS the Pontiac was on 1961 tires!, which is a whole nother story. Please pardon my senility... But that's neither here or there, as the rest of the info is right on.
I like the RMS vs peak comment, that's probably the original guy's answer.
Respectfully submitted,
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RogerMexiko
New member
Re: why is a 5W tube amp louder than a 20W SS amp
If tube amps are significantly louder, watt to watt, why isn't there a uniform measurement of loudness?
If tube amps are significantly louder, watt to watt, why isn't there a uniform measurement of loudness?
Blille
Well-known member
Re: why is a 5W tube amp louder than a 20W SS amp
Isn't that dB?
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Isn't that dB?
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devastone
Well-known member
Re: why is a 5W tube amp louder than a 20W SS amp
Watts is a measure of power, and was originally applied by James Watt (coincidence) to the output of steam engines, there weren't any Marshalls or Fenders in his day, if there were tubes, they were in their infancy, but there weren't electric guitars to amplify.
On the other topic here, is Ford hp the same as Ferrari hp? :33: :crazy:
- Si
Watts is a measure of power, and was originally applied by James Watt (coincidence) to the output of steam engines, there weren't any Marshalls or Fenders in his day, if there were tubes, they were in their infancy, but there weren't electric guitars to amplify.
On the other topic here, is Ford hp the same as Ferrari hp? :33: :crazy:
ginormous
Understatmentologist
Re: why is a 5W tube amp louder than a 20W SS amp
That's an issue sound and electronics engineers have been trying to solve for decades.
What started as dB (decibel) was the earliest effort, but it didn't show the difference in what was really going on electronically, versus what our ears heard.
Many technical communities are going to either dBV or dBu (essentially, different expressions of how much power is required to create one dB), or the European LUFS (loudness units, full scale).
For casual listeners and regular folks, this would be splitting hairs on a microscopic level.
That's an issue sound and electronics engineers have been trying to solve for decades.
What started as dB (decibel) was the earliest effort, but it didn't show the difference in what was really going on electronically, versus what our ears heard.
Many technical communities are going to either dBV or dBu (essentially, different expressions of how much power is required to create one dB), or the European LUFS (loudness units, full scale).
For casual listeners and regular folks, this would be splitting hairs on a microscopic level.
RogerMexiko
New member
Re: why is a 5W tube amp louder than a 20W SS amp
WOW! Thanks gang for all the interesting, informative and even the stuff I have no idea what it means. I'll walk away from here with my own conclusion - tube amps are louder than SS amps rated at the same watts. This is part real and part perception but for me bottom line they are louder and sound a heck of a lot better. Too bad they weigh so darn much. whats with transformer technology, it doesn't seem to have advanced in 75 years?
WOW! Thanks gang for all the interesting, informative and even the stuff I have no idea what it means. I'll walk away from here with my own conclusion - tube amps are louder than SS amps rated at the same watts. This is part real and part perception but for me bottom line they are louder and sound a heck of a lot better. Too bad they weigh so darn much. whats with transformer technology, it doesn't seem to have advanced in 75 years?
ginormous
Understatmentologist
Re: why is a 5W tube amp louder than a 20W SS amp
Class D transformer circuits are being designed for tubes, but they're expensive.
For guitar amps, the characteristics of the iron core transformer is part of what creates the sound. If it ain't broke...
As you alluded to, the basic circuit has been the same since the days of Marconi.
Class D transformer circuits are being designed for tubes, but they're expensive.
For guitar amps, the characteristics of the iron core transformer is part of what creates the sound. If it ain't broke...
Myaccount876
Amira-Maker
Re: why is a 5W tube amp louder than a 20W SS amp
You can have smaller (and cheaper) transformers, but you need bigger transformers for higher wattages, and the sound is massively affected by the output transformer. which can thin out the sound, sound dark and low-end heavy, and anywhere in between. It all depends on the design. The transformers in guitar amps are also typically made out of iron - hence the weight. Trying to "advance" transformer technology would be like trying to advance wheel technology - there isn't that much to them. They're pairs of inductors with winding ratios between pairs with the goal of stepping up or down AC. Not much else to it.
Also, the majority of information in this thread reaches a much different consensus - that generalizations about the loudness between tube amps and solid state amps are inaccurate in most cases, as an amps loudness is a much larger combination of factors than just the type of circuitry used. Even with the same wattage - which still isn't a great indicator of loudness. I can run a 20 watt tube amp in class A (less efficient) through a 1x8 cabinet with a speaker that has an efficiency of 90 dB while cutting upper mid frequencies, and put it up against a 20 watt solid state amp in class AB (more efficient) through a 4x12 cabinet with each speaker having an efficiency of 102 dB while boosting upper mid frequencies. I can guarantee you the solid state amp in this scenario will stomp all over the tube amp in volume (and it'd possibly sound better too). That's why it's plain inaccurate to claim one is louder than the other regardless of equal wattage.
Most of what you said is correct, but this bit is misleading. If you're talking a 3 dB difference between 60 dB and 63 dB, then you're right - it's barely noticeable. If you're talking a 3 dB difference between 100 dB and 103 dB, there's a very noticeable difference (in fact, 103 dB has over twice the amplitude of 100 dB, although amplitude isn't a direct measurement of loudness either). That's why it's important to remember that dB is a logarithmic function and a measurement of sound pressure levels - not the perception of loudness.
You can have smaller (and cheaper) transformers, but you need bigger transformers for higher wattages, and the sound is massively affected by the output transformer. which can thin out the sound, sound dark and low-end heavy, and anywhere in between. It all depends on the design. The transformers in guitar amps are also typically made out of iron - hence the weight. Trying to "advance" transformer technology would be like trying to advance wheel technology - there isn't that much to them. They're pairs of inductors with winding ratios between pairs with the goal of stepping up or down AC. Not much else to it.
Also, the majority of information in this thread reaches a much different consensus - that generalizations about the loudness between tube amps and solid state amps are inaccurate in most cases, as an amps loudness is a much larger combination of factors than just the type of circuitry used. Even with the same wattage - which still isn't a great indicator of loudness. I can run a 20 watt tube amp in class A (less efficient) through a 1x8 cabinet with a speaker that has an efficiency of 90 dB while cutting upper mid frequencies, and put it up against a 20 watt solid state amp in class AB (more efficient) through a 4x12 cabinet with each speaker having an efficiency of 102 dB while boosting upper mid frequencies. I can guarantee you the solid state amp in this scenario will stomp all over the tube amp in volume (and it'd possibly sound better too). That's why it's plain inaccurate to claim one is louder than the other regardless of equal wattage.
Most of what you said is correct, but this bit is misleading. If you're talking a 3 dB difference between 60 dB and 63 dB, then you're right - it's barely noticeable. If you're talking a 3 dB difference between 100 dB and 103 dB, there's a very noticeable difference (in fact, 103 dB has over twice the amplitude of 100 dB, although amplitude isn't a direct measurement of loudness either). That's why it's important to remember that dB is a logarithmic function and a measurement of sound pressure levels - not the perception of loudness.
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GoldenVulture
Braindeadologist
Re: why is a 5W tube amp louder than a 20W SS amp
Our ears don't have a linear response. Phons are a measurement of that.
Our non linear response will affect your perception of sound depending on it's volume level.
- http://www.google.com.au/url?sa=t&r...sg=AFQjCNGsY3Z7W-Wdd37kWOuecj_WBkAcUA&cad=rja -
Our ears don't have a linear response. Phons are a measurement of that.
Our non linear response will affect your perception of sound depending on it's volume level.
- http://www.google.com.au/url?sa=t&r...sg=AFQjCNGsY3Z7W-Wdd37kWOuecj_WBkAcUA&cad=rja -
RogerMexiko
New member
Re: why is a 5W tube amp louder than a 20W SS amp
You stacked the deck by using class A vs class AB and a little old 8" speaker with 90db sensitivity vs 4 x 12 speakers with 102 db sensitivity. Just the speaker arrangement alone results in a 20% db SPL loudness reduction for the tube amp set up. I'm just guessing but I'd think the frequency response between the different set of speakers would have a significant effect on the "perceptive" loudness factor.
You stacked the deck by using class A vs class AB and a little old 8" speaker with 90db sensitivity vs 4 x 12 speakers with 102 db sensitivity. Just the speaker arrangement alone results in a 20% db SPL loudness reduction for the tube amp set up. I'm just guessing but I'd think the frequency response between the different set of speakers would have a significant effect on the "perceptive" loudness factor.
