Tube Watts = SS Watts ??

[beans-on-toast]

Saying P=VI makes it easier and is an acceptable standard for amps. Power with reactive elements such as capacitors and inductors involved, becomes complex. They use imaginary numbers and vectors to characterize it.


AC power - Wikipedia


Things are never as simple as they appear.

 

[nilorius]

The same.

 

[bassinflorida]

No, but the tube amp runs at higher voltage than the mains, and a solid state at lower, so the electricity *inside* an SVT is more likely to kill you.

Not necessarily. Study the relationship between voltage and current.

 

[Lowbrow]

Long story short, the cab maker you spoke to was greatly exaggerating.

 

[JimmyM]

No, but the tube amp runs at higher voltage than the mains, and a solid state at lower, so the electricity *inside* an SVT is more likely to kill you.

You know what I do in that case? I don't touch anything inside the amp when it's plugged in and I stay away from the caps when I have to open it up

 

[JimmyM]

Dont you use a portaflex? The Traynor YBA 300 is on a whole different level when it comes to tube replacements; It’s expensive and tedious.

I have a couple SVT's too. 12 power tubes is a lot, but do you have to replace all of them when one goes out?

 

[JimmyM]

Let me point out the following:

if you make a research on the market amongst bass amp manufacturers, you will probably find out that they offer SS amps up to (usually) 800-1200 watts. On the other hand, all-tube amps' manufacturers (Ampeg, Fender, Orange) offer amps up to 300 watts. Do you think that it's because all-tube amps' users like to play less loud?

No, it's because anything more than 300w and you start to get into the truly impractical.

 

[Zbysek]

No, it's because anything more than 300w and you start to get into the truly impractical.

IMHO, the dividing line between practical and impractical is much lower...

 

[JimmyM]

IMHO, the dividing line between practical and impractical is much lower...

I suppose for some it is. I still see folks lug them around, though.

 

[micguy]

Not necessarily. Study the relationship between voltage and current.

I have - the resistance you pose is fairly high - you don't conduct a lot of current compared to a wire or a loudspeaker. Net result of this is that the voltage that's present on the rails of an amp quantifies the hazard to someone messing around in it very well - neither amp's power supply is going to be loaded down when you attach yourself to it - twice the voltage will put twice the current through you, so in the case of amplifiers, more voltage = more hazard.

 

[Zbysek]

I suppose for some it is. I still see folks lug them around, though.

I know. As a lawyer, I see people doing all sorts of stuff...

Sorry for off-topic. Take care, Jimmy.

 

[Sparkl]

Threads like this are why agedhorse got pissed off and started getting unpleasant with people. I don't blame him a bit.

There is always going to be a discrepancy between engineers and musicians. You cannot just explain everything with technical information just as you cannot do the same by just feeling the equipment. In the end it is all about what works for someone.

If I ever learned something it's that watts don't mean poop until you actually try something out. I was completely shocked at how much pleasant loudness (I don't even care about SPL anymore) a CTS Alnico Ampeg SVT810 (a "measly" 250W RMS rated cab) puts out. It completely stomps over my other gear including the Aguilar DB410 (granted, comparing with the same amp, in this case my Ampeg V4B).

Does this say much? Not really. But in terms of practicality, using my amps in the signature, this is the result I get when comparing with each other. And I can say I am the most satisfied when combining my V4B with either DB410 or SVT810 and even though on paper we could say I could own a 2kw amp with a 3kw RMS rated speaker and achieve 150dB SPL all by having to carry 30kg instead of 130, it just doesn't do much to me. So I use it the way I feel like using it.

It is what it is.

 

[Glenn Johnson]

I've done the math and performed numerous studies in 17 different countries and have determined that 1 tube watt is equal to 14.374568 SS watts.

 

[backin82]

The shortest version that seems to be somewhat of a consensus is as follows (and I'm sure I'll get something wrong).

With solid state, that maximum output is a hard figure. If you try to go past 500 watts of output on a 500W amp, you can damage things. And the sound usually isn't pleasing anyway. With tubes (and the rest of the circuit, including output transformers and whatnot) you can push them "past" their rating somewhat into a distorted tone (not an angry tone yet but something a little wooly) that is still pleasing to many ears. In the view of some, it's not "past" it's rating, rather the extreme highest output of a tube amp sounds a lot better than the extreme highest rated output of a SS amp.

It's a perception thing.

So watts are watts. However, the PERCEPTION is that a 30W tube head is a lot louder than a 30W SS head simply because up at the highest output levels of a tube amp the sound can be pleasing and it usually won't damage things.

These waters are murky at best, and like trying to navigate through drying concrete at worst.

Short version: There is no equivalent tube to SS power rating of watts.... like the 50 to 300 ratio your tech claims simply isn't true. But, to many, the perception is that (all else being equal in the signal chain) a 100W tube head will get a lot louder than a 100W SS head. In general, it seems that you can squeeze a bit more volume out of an equally rated tube amp because of how the circuit reacts to everything else in the chain.

Hope that helps.

Thanks for the thorough explanation! I've read a lot of threads about this over the years, and the snark is so strong with topics like this, that's its difficult to wade through the garbage posts and learn what's real. Your post above REALLY made it understandable. Thanks for taking the time to explain, and thanks for not being a d-bag about an honest post by the OP. Internet win!

 

[dramatwist]

Well, you are no expert as opposed to a reputable cab maker.

I would suggest the 5-watt amp was probably solid state and the Bassman, of course is a tube amp. If you are talking clean, pretty much anything is louder than a 50 watt Bassman.

Both were tube amps... for the record.

 

[2F/2F]

Watts are Watts, if you are talking about the same exact methods/calculations for arriving at the rating. But Watts aren't necessarily what you hear.

Then once you've adjusted for different rating methods, you still run into the fact that every different amp model has a different tone – "tone" being a combination of e.q. and the character of the amp's distortion – which all affect "apparent" power to your ears. But what your ears think of as "power" isn't necessarily linearly in line with what actual electrical power is, so you introduce the dumb human brain, with all of its incorrect notions, into the fray.

Then, you also usually aren't hearing the tube and solid state amps through identical speaker cabs, so the cabs and the speakers become variables.

AFAIK, there does not exist an amp that is basically identical electronically, yet has one version with a tube power amp and one with a solid state power amp, both with identical power. Separate pre and power amps would be the closest you will get to running into this comparison on a practical, real-world level.

In short, it's near impossible to eliminate all variables to make a direct comparison. The differences you will hear in the real world will be differences of e.q. and distortion character more than directly hearing differences in raw power.

Bottom lines: 1) Watts are watts, but there is far more at play than simple electrical power in determining how an amp sounds. Almost no two different amps will sound the same, regardless of whether they are tube or solid state, even running at identical power. 2) The question is almost useless in the real world, so the comparison isn't even worth making. You'll very rarely have the choice of using either tube or solid state power sections, identically powered, to drive otherwise identical amps.

In other words, just use your ears to determine whether an amp sounds to your liking or not. Specs alone won't make the decision for you.

 

[two fingers]

Thanks for the thorough explanation! I've read a lot of threads about this over the years, and the snark is so strong with topics like this, that's its difficult to wade through the garbage posts and learn what's real. Your post above REALLY made it understandable. Thanks for taking the time to explain, and thanks for not being a d-bag about an honest post by the OP. Internet win!

Years ago I came here with a closed mind and a lot of stuff I thought I knew. The more I got proven wrong the more my mind opened. So, these days, I try to give everyone the benefit of of the doubt that several offered me back then. Like you said, it's an honest question. But it's surrounded by a ton of mythology that clouds the issue.

Short version: There's no reason to shove anyone's question down his/her throat. Just answer politely or move on to something else.

Glad I was able to clear something up for you.

 

[Passinwind]

No, but the tube amp runs at higher voltage than the mains, and a solid state at lower, so the electricity *inside* an SVT is more likely to kill you.

You might want to take a look at the first stage in many current SMPS based amps. That stage is often a rectifier/voltage doubler, with no transformer isolation to the line input at all. It's highly isolated by other means (at least in certified commercial pieces) and probably far less likely to bite you than an exposed anode rail in an SVT, but it's definitely still serious business.

 

[okcrum]

No, it's because anything more than 300w and you start to get into the truly impractical.

Where there's a will, there's a way. A band whose original drummer I knew called Cast In Bronze tours with a portable 2-1/2 octave carillon, which weighs about 4 tons.

They do tend to book extended stay gigs like state fairs and DisneyWorld that can do heavy rigging.

With 4 tons to play with, you could pull off 10-20 thousand classic tube watts.

EDIT: Almost forgot, the fans blowers might make it tough to use on those low volume acoustic gigs.

 

[Wisebass]

You guys made me laugh!

I still see folks lug them around, though.

I know. As a lawyer, I see people doing all sorts of stuff...

I hope that luggin' around an SVT is not illegal!

It' s by far the best method to get rid of the calories,

you get on your belly by drinking Czech beer!


greetings

Wise