Amp volume question

[agalamba]

Hey guys, sorry for the extremely newbie question but here it is. I have been reading your forum for a while now and I don´t understand a few things about amplifiers. What really matters to an amp´s volume? I´ve read that extension cabinets don´t make a difference, and I can kind of understand that. But I have also heard that the Wattage of the amp doesn´t say a lot about its volume either... I used to think that a 30W amp would be louder than a 22W tube amp for example... And why are tube amps of smaller Wattage so much louder than Solid State amps? Are these wattages measured in different ways? Is there like a table that says: 65Watt Solid State = 30Watt tube?? Or something like that?

Thanks a lot for your time and sorry to bother you with such beginner´s questions!

[Tele-Bob]

Alot of "percieved" volume has to do with gain. A 100 watt solid state amp with the gain cranked and the volume on 10, will get absolutely squashed by a 20 watt Deluxe Reverb. I honestly don't know the scientific reasons for this, and I'm not going to get into the whole tube vs solid state debate because there are far too many variables to start stating "absolutes". There are certain instances where one style amp works better than another, and that varies greatly depending on who you ask, and what they play.

In all seriousness, I will suggest that you just go out there and play, and listen, and then form your own opinion that you could share with us and hope it doesn't turn into the heated debate of "tube vs solid state" that seems to be so popular.

[Offshore Angler]

Well, the ear is a logarithmic device. So a 100W amp will sound TWICE as loud as a 10W, not 10x. Also, the speaker's efficiency is extremely important.
So the difference between a 22W and a 50W really isn't that great.

But one of MY absolutes - if you will - is that a small amp cranked up sounds better than a big one on 2. YMMV.

[Wilko]

There also difference in how the power is measured as well as what those numbers mean.

Peak power is the measurement of the maximum power produced. The size of the waveform. Many SS amps are measrured that way.

RMS power is the "root of the Mean Squared" and will be about 60% of the peak waveform. That measurement is taken at the highest point just before distortion kicks in.

With that in mind, know that a "cranked" 22 watt amp will be actually pushing way more than 22 watts.

Then factor in all the load on that amp, speaker efficiencey, dispersion angle, and such for actual "volume" in SPL (sound pressure level) which will be different depending on proximity.

[Tele-Bob]

And to further confuse the matter, when two or more amps are labeled at their RMS rating, then you can actually compare them through the same speaker and get a realistic estimation of the actual volume they put out.

[JAM]

I think most amps are rated at rms output. But it's at a steady sine wave rather than a dynamic signal like guitar (or music). Tubes must be able to put out short term peaks much greater than SS amps. For example if I measure my Fender 85 (a small SS amp I use for practice and teaching) it puts out about 50W (sine wave). My 65 Princeton puts out about 16W (also sine wave) but sounds louder with my guitar than the 85.

[Wilko]

And for a touch more confusion:

The FREQUENCY being measured makes a difference.

Amps will produce different power at different frequency bands.

Couple that with the effective frequency response of your speakers for more variation (supplimental and/or subractive)

[Constellation80]

for some reason I find a tube amp seems to be 12db louder then a SS of same wattage. Is there a reason for this? or am I imagining it?

[agalamba]

Wow! Thanks a lot for your reponses. I kind of asked this question to answer a friend of mine, because I said I was going to get myself a Peavey Classic 30 for playing the local clubs (800 people capacity - Miced amplifier), and he said it wouldn´t be enough. So i was kind of trying to prove to him that it will be enough. So thank a lot for the replies. I will pass the link over to the guy to get him really confused!

[Kap'n]

for some reason I find a tube amp seems to be 12db louder then a SS of same wattage. Is there a reason for this? or am I imagining it?

Are you sure it sounds exactly like an amp with sixteen times the power?

So a BF champ sounds as loud as a 96W sold state amp through the same speaker...assuming it didn't blow, of course?

A Princeton sounds as loud as a 192W SS amp?

A BF twin sounds as loud as a 1,360W SS amp?

A Marshall Major sounds as loud as a 3,200W ss amp.

OK, I'd believe the last two. :lol

I think you're imagining it.

[detuned]

Yet more variables:
Number of speakers (more air=more volume)
Type of cabinet (open vs. closed)
EQ setting for amp
What else is in the band (power trio, horn band, 3+ gtr country band,etc.)

Psychoacoustics is a tricky business...

[thetallcoolone]

If you start figuring in all the variables that can be factored in, no one will ever be able to figure the hows and whys of the original question by agalamba.

Lets assume you have a 50W SS amp and a 50W tube amp.
Put'em thru the same cabinet with the same speaker.
Use the same guitar and same setup.
Both in the same room.
The perceived sound will be louder from the tube amp.
Why?

Is it because of the circuitry, the parts needed by a tube amps?
Is it because the way the tubes handles the signal?
The physical properties of tubes are very different than the ones of the transistors. Is this the main reason?

As T-B said, no talk about the qualities of tube vs SS, just the perceived volume.

[Wilko]

The qualities effect the perceived volume. The pattern of distortion alone sets up a more complex wavefrom in a tube amp that can support a higher overall SPL.

It's sort of like a class A Class AB thing. If you wave is pushing harder through more of the cycle, it will be louder than a pure sine that only pushes pulses. You ear will be like one of the tubes in a push pull. You hear the push as sound pressure from one side of the wave.

[Kap'n]

Is it because of the circuitry, the parts needed by a tube amps?
Is it because the way the tubes handles the signal?
The physical properties of tubes are very different than the ones of the transistors. Is this the main reason?

I'm not sure. Certainly the resistors/capacitors, etc. are all the same. The big things are:

Virtually all tube amps have an output transformer, the design of which impacts the sound.(a handful of hi-fi ones are output transformerless)

Virtually all well-designed modern transistor power amps are never driven into clipping - a distorted pramp sound is fed into a clean power amp. Because of this, signal is limited so the power amp will only approach it's rated clean output, at which THD is usually measured in fractions of a percent.

Tube amps are usually rated at 5% THD, but in practice, often run over that.

Funny psychoacoustic things happen when a signal is distorted by the sum of the parts of a tube amplifier.

[JAM]

Some years back one of the HiFi magazines would rate power amp wattage as a function of decibels (dBw), in an effort to show how actual power output compares in terms of SPL. Also some amps can put out significant more short term power than others (dynamic headroom), so that a 50W amp with 3db of headroom would sound as loud as a 100w without any additional short term power. I've always wondered if this is the case with tube amps vs SS amps.

[CocoTone]

You guys are getting a bit too deep for my old- school mentality. To me, all amps have a sweet spot, and that spot depends on your guitar of course, but by what also moves you to dig deeper. That majic `spot` will move around, depending on the room, weather, etc,, and a good amp will always get you into the neighbourhood with some good tweaking.
Now, the volume comes with that sweet spot, and unless you can attenuate to satisfation, you might be loud,, most often that is the case with most amps over 20 watts, and we all know how loud a good 20 watter can be. I really can`t figure how I played for so many years with out an attenuator, and i went most of those years being ridiculed for my excessive volume.
It is such a useful, and audience-friendly addition to anyone`s rig. You will be appreciated more, and that makes everyyone play better.:yay

CT.:ahem

[fancychords]

It's been my experience that when they advertise s.s. amps it's under a 4 ohm load and typically amps with one speaker are always 8 ohms...tube amps are always rated with under their 8 ohm load...
I first noticed this whith Carvin sx amps they would advertise their single 12 amp as 100 watts which it was<but with the 8 ohm speaker that it was shipped with it would just put out out 50 watts if that much...

[Tele-Bob]

So the long answer to the short question is, the answers really don't matter. Just get out there, play through some amps and see which one blows your dress up. When I hear an amp that sounds great I don't care how it produces that sound so much as the fact that it does produce that sound. In light of actual experience, explanations have a habit of fading away.

[Plugger]

Wow! Thanks a lot for your reponses. I kind of asked this question to answer a friend of mine, because I said I was going to get myself a Peavey Classic 30 for playing the local clubs (800 people capacity - Miced amplifier), and he said it wouldn´t be enough. So i was kind of trying to prove to him that it will be enough. So thank a lot for the replies. I will pass the link over to the guy to get him really confused!

If the amplifier is going to be miced, how it could it not be loud enough? This doesn't make sense.

Unless by "miced" you mean vermin have eaten out your speaker cones or something...

-Mark

[CocoTone]

If the amplifier is going to be miced, how it could it not be loud enough? This doesn't make sense.

Unless by "miced" you mean vermin have eaten out your speaker cones or something...

-Mark

[agalamba]

If the amplifier is going to be miced, how it could it not be loud enough? This doesn't make sense.

Unless by "miced" you mean vermin have eaten out your speaker cones or something...

You didn´t get what I was trying to say. Even though the amp is going to be miced i have to rely on it solely for my stage sound. It has to be loud enough so that all the band hears it. I can´t rely on the PA to give me "return" because we play very unorganized gigs, where we show up, plug everything and start playing... And we do that 3 times a night sometimes, that´s why we can´t make a sound check or stuff like that. What I meant was: I need and amp that will be heard, even in a large stage - we eventually play larger venues, by the whole band.

[Tele-Bob]

You may need to run an extension cabinet on the other side of the stage then.

[TT100]

You didn´t get what I was trying to say. Even though the amp is going to be miced i have to rely on it solely for my stage sound. It has to be loud enough so that all the band hears it. I can´t rely on the PA to give me "return" because we play very unorganized gigs, where we show up, plug everything and start playing... And we do that 3 times a night sometimes, that´s why we can´t make a sound check or stuff like that. What I meant was: I need and amp that will be heard, even in a large stage - we eventually play larger venues, by the whole band.

You're reminding me of the '70s. Depends on a lot. What type music, what other instruments in the band, power drummer or laid back, etc.

If the bass player pulls out an old Ampeg and your drummer beats the hell out of the skins, on a large stage or with people jammed up against a low stage I'm thinking a 30W 1x12 might get lost if you're using it for a monitor also. You might have to crank it well past it's optimum point to get the sound you want too.

Might have to think larger. 50W 2x12 or 4x10? What kind of music?

TT

[tenebrae]

If the bass player pulls out an old Ampeg

Then nothing will save you! It's duck and cover time. Those old SVTs are seriously dangerous :) ...in a good way, of course.

Tenebrae

[agalamba]

I play in a cover band, so we have to cover everything from Light blues to Hard rock... Right now we are playing lighter stuff though... The thing is, I wanted to get the smallest combo possible. 2x12 or 4x10 are out of question here... Way too heavy and big to carry around every night. This is why i thought of the C30, also I tested it on a local store and I really liked it. I also tested a couple of Laneys (LC-50 and VC-30), but they didn´t sound as good as the Peavey...

We don´t usually play very loud, there is voice, one bass, one keyboard an a drummer. The drummer is laid back, the loudest guy in band is the keyboard player, but he is a musical genious, so I let him play as loud as he wants! So In wanted to get the C30 because I liked its sound and because it is small and light.

[TT100]

Sounds like portable is high on the spec list then. Like TB said, go out and try a few out then, but try them at the volume you'll play at.

The sound you want at the volume you need.

Check this out. I had one for 18 years and they are very very good for the cash. 60 watts clean and loud, active eq, rev, built like a tank. Somewhere around 35-40lbs.

Carvin X-60

Another option, if you want new is the Traynor YCV40. Rave reviews.

TT