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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
atmasphere's avatar
atmasphere
11,807 posts
 
Mapman, that is as succinct an explanation as I have ever heard. Well done.
unsound
7,329 posts
 
Mapman, Atmasphere, not everyone take offense to the same things.
mapman's avatar
mapman
22,210 posts
 
Unsound,

That is true.

I suppose that could be one reason perhaps why many are tube fans yet many are not.
atmasphere's avatar
atmasphere
11,807 posts
 
Unsound, what is meant by offense is not really a matter of taste. Back in the 1960s, GE did a test where they played music and test tones for people and gauged the response.

What they did was to introduce two types of distortion- even lower orders, and higher odd orders, in two tests. What they found was that people will tolerate without objection up to about 30% distortion if its all lower orders, but tiny amounts of odd orders, less than 0.1% was highly objectionable!

IOW, what they found out was that the human ear listens for the 5th, 7th and 9th harmonics in order to determine the volume of a sound and that we are sensitive to distortions as low as 0.001%, where we really don't care about lower orders (the 2nd,3rd and 4th).

This is also the difference between tubes and transistors as far as distortion goes. I myself do not like what many have come to call the 'tube coloration' and I have found that with careful design there is no reason to have to tolerate it either. Nor do I like transistor coloration, but its a lot harder to design transistor amps that lack it; all of them that I have heard that lack transistor coloration are all also zero feedback class A designs, I think not out of coincidence.

I don't fault anyone for disdaining the typical distortions that are easily heard in a lot of gear- I feel the same way.
unsound
7,329 posts
 
Atmasphere, your points are well taken but, I'm doubt that these findings were experienced by 100% of the people tested. Just as in other areas of audio, for what ever reason some people seem to be more or less sensitive to some aspects more or less than others. There are other considerations that need to be considered; budget, heat, space, compatibility with connected gear, etc.. When the entire equation is put forth, new sources of "offense" can be introduced. In certain circumstances the benefits of one technology are over ridden by the exposure or introduction of new flaws.
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