How loud is a 150 W SS amp compared to a 30 W Tube amp?

http://www.ultimate-guitar.com/columns/the_guide_to/the_guide_to_finding_an_amp.html

example; a 20 watt tube amp is as loud to the human ear as a 50 watt solid state amp (the solid state amp is 250% the wattage of the tube amp, but they are approximately the same number of decibles.

A bigger impact on volume is cabinet design and speakers (how many, the size). In order to "double" your volume by wattage you have to multiply your wattage by ten.

I don't seem to have a link on me at the moment... but there's some good information to be had on the net about the way the tube amp's "percieved volume" is louder, but it's a trick of the way the harmonics align or something.

The other hidden variable there is the way that tubes distort vs. the way solid state amps distort. Turn most solid state amps up to 8, and they'll start to buzz and sound like donkey, but turn a tube amp up to 8 and they'll be in their prime. In that way, a smaller tube amp can cover a bigger venue than a comparatively sized solid state: it's not a question of "how loud does it go?", intstead it's "how loud does it go and still sound good?"

Blah blah blah.

But yes, tubes sound louder and cabinet and speaker design and placement mean a lot more. Play a 15 watt amp through a 4x12 and be prepared to be shocked, it's the kind of experience that will totally change how you think about wattage.

Talking about tube amps and cabs, I was thinking about getting an Epi Valve Junior (5 watt Class A) and then connecting it to a 4x12 cab. Would this have anough decibles to get over a drummer?

The smallest I've had experience with is a 15 watt SS connected to a 4x10. It sounded good, and would have probably kept up with a drummer for quieter work.

I can't predict how a 4x12 (more speaker) with only 5 watts (1/3) would be, and then throw in the variable of tube vs. solid state. I'd say give it a whack, try it out at the store. You're sure the amp has an extension speaker jack?

I don't know how accurate this is but I read in Guitar World that a tube amp is about three times louder then your solid state or digital amps: so that'd make a 30 watt tube amp as loud as a 90 watt ss or digital, I don't know how accurate it is, but after reading previous posts it seems like a decent enough comparison.

I don't know how accurate this is but I read in Guitar World that a tube amp is about three times louder then your solid state or digital amps: so that'd make a 30 watt tube amp as loud as a 90 watt ss or digital, I don't know how accurate it is, but after reading previous posts it seems like a decent enough comparison.

No, doubling wattage does not double volume, so the 30 -> 90 is not accurate. It takes a wattage increase of 10x to double the volume, because dB is a logarithmic measurement and blah blah blah. Also, digital amps are Solid State.

Search for "dB SPL" on google and you'll find a wealth of info.

yeah, i didn't mean that doubling wattage doubles power... i just meant that tube amps were 3 times more powerful then solid states of the same wattage, according to the magazine i read.

I recently bought a Crate GT212 -- solid state. It keeps up with the tube amps in the band just fine. It's 120 watts, but part of the secret for volume on this amp is that the 120 watts power two 12 inch speakers. Two speakers make for better volume because they move more air. It's a nice amp. I'm very pleased with it.

Watts are watts. A 50W solid state amp should be just as loud as a 50W tube amp through the same speaker. But it is true that tube amps are "perceived" to be louder. Hey, if it sounds louder, IT IS LOUDER. :D It's one of those great mysteries.

I think the big difference is the speaker. Some amps have more efficient speaker(s) than other amps. I own a 40W Fender Hot Rod Deluxe and a 40W Marshall DSL401. They are both a 1 X 12. The HRD will blow the Marshall away easily when it comes to volume. There is no comparison whatsoever. I am not sure my Marshall could handle a gig in a medium sized club or a big crowd. The HRD will handle anything. IT IS LOUD!

It is cheaper to buy a more efficient speaker than a more powerful amp. A speaker rated 103 dB @ 1W/1M will be 6 decibels louder than a speaker rated 97 dB @ 1W/1M at any wattage.

Adding an extension cabinet will increase volume. Adding an identical speaker in close proximity is said to give you a 3 decibel volume increase. I don't believe this is entirely true as you are now sharing your amps watts equally, but you are probably getting at least 2 dB increase. You are pushing more air. It will sound fuller and cover a greater area.

Everytime you double the watts to a speaker(s) you get a 3 decibel increase in volume. So a 100W amp should be 3 dB louder than a 50W amp into the same speaker. 12 decibels is considered to be a doubling of volume (twice as loud). So 3 decibels is a noticable increase, but not anywhere near a doubling in volume.

Tube amps are far more expensive than most solid state amps. People expect quaility when they shell out big bucks for an amp. I think most tube amps probably come with a higher quality and more efficient speaker than a less expensive solid state amp. I think this more than anything explains why most tube amps seem to be far louder than SS amps of the same wattage. I could be wrong, but I think that's it.

You must also keep in mind how mcuh your speaker will handle. I have a 100 watt Line6 and the speaker farts out before I get the volume to 6.

Tube amps are commonly way underrated in power, since a common standard is to rate their power at some level of total harmonic distortion like 10% THD (which sounds squeaky clean), and guitarists like to push them to much higher levels of power and distortion.

Tube amps are commonly way underrated in power, since a common standard is to rate their power at some level of total harmonic distortion like 10% THD (which sounds squeaky clean), and guitarists like to push them to much higher levels of power and distortion.

What?! Is that accurate? From what limited amounts of material I've read, I gathered that by 2% THD, sound was a jumble. Maybe I misread something.

Hmm, just did some more reading, looks like THD in any amounts is only scary during sound reproduction, such as in pro-audio applications or studio monitoring settings. In that setting small amounts of THD are very undesirable, but 20%+ apparently can be very acceptable for guitar amps.