Solid State VS Tube

What is the typical conversion for solid state watts vs tube watts? I know it may vary with factors, but generally what is it?

Any tube amp is required to add higher volume (for tubes to get warmed up) and that's how tube amp sounds really loud. If you take solid state and tube one with power of 50 watts, then they will be pretty same in loudness (and in power). The bigger speakers, the more loudness and power they'll deliver

My lead guitarists 15W tube seems to be comparable to my solid state 100W, FWIW. Unless you are going to play a big auditorium (2000 people), 100W tube might be overkill.

I misspoke. It's a switchable 5 to 3 watt tube amp. I guess based on my very limited data set I will venture a ratio of 20:1...

Typically, Tube seems to be a 3:1 in my experience. The speakers can make a huge difference however. Also, the largest problem with solid state is not the volume, but it's ability to hold it's own in the mix.

I've heard (this may or may not be true) that the wattage doesn't mean much eitherway - the efficiency of different amp/speaker combos is what's important. Although, obviously, in general higher wattage means higher volume, there are no hard set rules.

Having said that, I've only ever come across REALLY loud 50w tube amps. I've never come across a really loud 50w transistor amp. So I'd say probably tubes are much louder. Not sure why.

However I use a pair of 100w HH studio power baby transistor amps and they are LOUD. But I think they use MOSFET, which is not often used now..

I'd go along with the 3:1 ratio if they're run through the same speaker cabinets. Some tube amps are just incredibly loud. I have a 100w Fender Twin which can run at 33w - even at the low power setting it's extremely loud. I've rarely used it at 100W; it's just too loud for anything but an outdoor festival. Vox AC30's are very loud as well. . It's a disadvantage though in many cases. Tube amps sound best when they're turned up. If you have to run them at a low volume setting, they don't sound anywhere near as good.

Watts are watts -- no difference.
Amps are generally rated for a given amount of distortion, and that's the real difference between tube and solid state amps. All amps can produce MORE than their rated power, but distortion increases.

Guitarists think that distortion of a tube-based power amp is more pleasant than that of a solid state amp ( that was true back in the '60's, at least, and most guitar players are well and truly stuck there gear-wise), so they will routinely drive a tube amp into double the rated power without a thought and be happy with it.

As it turns out, most higher-end solid state amps designed for guitar these days actually do NOT get nasty and gritty (a tube emulation circuit designed and never patented by an engineer from Carvin back in the early '70's or late '60's does a good job of mitigating that). But as with the "breathing" nitrocellulose lacquer and "old-growth" stories, the mythology persists. And the cheapo beginner amps are generally unwonderful, so they support that myth.

At about 100W for tube amps, transformer weight and hearing loss come together to generally limit things. A typical head only can weigh between 40 and 70 lbs. My solid state bass amp weighs in at around 10 lbs. And it has 1500W.