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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
aball
2,018 posts
 
Oh yes, sorry for the confusion, Paul is right. I had SE Class A in mind. That's the type of amp I've been on the prowl for so that's what I've been thinking about lately.

My comments still apply for Class A push-pull however because they have the same ungapped core design as Class B push-pull since the two halves of each channel remain in opposite polarity and similarly sum in the secondaries. Hence my generalization from the circuit design point-of-view.

Arthur
orpheus10
8,668 posts
 
There is a scientific explanation as to why Class-A amps sound better than Class-B,but there is no scientific explanation as to why tube sounds as loud as solid state when the tube is less powerful.
mapman's avatar
mapman
22,342 posts
 
Power output I believe, regardless of amp technology used, translates essentially only to how loud things should go, all other factors aside.

This does not say anything about how optimally an amp drives a particular speaker design. By optimally I mean that all frequencies are delivered essentially on equal ground even as the load impedance varies by frequency from the nominal, generalized overall rating.

Distortion will be lower when an amp drives a speaker with higher input impedance in general I believe, all other factors aside.

In general SS amps are better able to drive speakers with lower input impedance more optimally and with lower distortion for properly balanced sound than tube amps (in general).

That is my general understanding. Please correct me if I am off base here.

My point is that power output alone ma determine the quantity of sound (volume/spl) that can be produced, but not the quality, even at lower volumes. Other factors come into play there.
atmasphere's avatar
atmasphere
11,862 posts
 
Orpheus10 and Mapman, the reason tubes seem more powerful has to do with the way we perceive sound and the different ways that tubes and transistors make distortion. I would look at some of Arthur's comments above- they are right on the money.

I think I also had some of this explained above too- if I need to clarify it just let me know.
mapman's avatar
mapman
22,342 posts
 
Atmasphere.

No further clarification needed on my behalf. Transients are key. Its pretty clear to me that its mostly about details relating to distortion and how different factors contribute to that, as you say.
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