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Power output of tube amps compared to solid states

I'm having a hard time trying to figure out how tube amp power output relates to solid state power output. I've been looking at the classifieds for tube amps and I see lots of tube amps with 50w or 60w output, but nothing close to the 250w output typical of solid state amps.

So I have no idea what type of tube amp is required for my set up, right now I'm using totem forests with a required power rating of 150w-200w at 8ohms. The bass is so powerful on these that I have the sub crossover set to 40hz.

My question is, are tube amps so efficient that 50w from a tube sounds like 150w from a solid state? Or will 50w output from a tube severely limit how loud I can play my speakers? If so, are tubes usually meant to be driving super-high efficiency speakers?

I had previously tried a tube pre-amp with a solid state power amp (both musical fidelity) and didn't like the results because the imaging suffered greatly, even though the music sounded nicer from a distance. Now I want to try a solid state pre-amp (bryston) with a tube power amp (no idea which brand to look at), but I don't know how much power output I need or if it will even be possible with my speakers. Does anyone know what I would require?
acrossley
mapman's avatar
mapman
22,472 posts
 
Atmasphere,

What speakers cannot be driven by SS and why?

Thanks!
pubul57
3,712 posts
 
Is there such a thing? Seems like SS can drive anything, it just won't sound as good as tubes with speakers that can be driven effectively by tubes.
unsound
7,333 posts
 
Atmasphere, it's exactly here where we diverge. IME, speakers both objectively and subjectively vary more than other components, and have a more varied response in different rooms/setups. With that said, all the speakers I seem to prefer, work best with ss. It seems to me that speakers that work best with tubes, do so with that intention, and seem to suffer much greater compromises in order to do so. IMHO, those compromises swamp what ever advantages tubes might(?)offer. With that said, it would seem to me that the easiest path to a system that sounds like real music is to build a system around the constraints we have the least control of; budget/room, and the speakers which adapt to those variables more so than any other components, and to their more varied unique voices to which our own unique specific sensitivities must adapt to more so than with any other components. YMMV :-).
unsound
7,333 posts
 
Mapman, Pubul57, it would seem to me that speakers with a benign phase angle and a higher impedance rating might be better served with tube amplification over ss amplification, that would loose power with an increasing impedance rating.
atmasphere's avatar
atmasphere
11,959 posts
 
Here are some speakers that are not well driven by transistors: ESLs (too bright, no bass unless the speaker is only a foot or two from the wall), horns (usually very shrill, due to the reactive nature of the drivers), full-range high efficiency drivers (similar to horns), any box speaker wherein the designer was expecting a power response from the amplifier rather than a voltage response.

An example of the latter is the Wilson Watt/Puppy, which had a resonance in the tweeter. This was controlled by a trap filter set at the frequency of the resonance. This caused a 2 ohm impedance at that frequency (2KHz). Tube amps, encountering that impedance, do not make much power and everything is good. Transistors dump power into that load, resulting in brightness. This is why you see such conflicting opinion on that speaker.

for more info see:
http://www.atma-sphere.com/papers/paradigm_paper2.html

So IME, since I prefer the reduced coloration of tubes, it makes sense to me to choose a speaker that works with that, rather than one that requires a transistor amp to sound right. IOW, that's why you choose the amplification first, then the speaker. Otherwise you can flush some big money down the loo.
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