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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
rugyboogie
199 posts
 
This is strictly my opinion/impressions

Having owned some SS amps SUMO, PS Audio, Hafler, ML33, ML 33h, ASR Emitter II over the past 20 years I have made a switch to tubes. Have settled for a 211 SET and am really enjoying it. Its 18 watts of pure bliss.
Friend brought over his VIVA mono's as well as his MACTONE.
The Viva's were great and the Mactone was nice at lower volumes.
Do most of my listening around 75 to 85 db, above 95 getting a little loud for me
For me the music that comes through the tubes is much more involving. In my case anyways.
Was really curious on having a SS power house amp in with my 18 watter.
Reading HP's review, decided to try a pair of 1000 watt Brystons mono blocks.
Had them on loan for a week and they disappointed me to say the least.
This is not to say that a SS may not reside in my home but for now I am converted.

YMMV.
unsound
7,333 posts
 
Atmasphere, the "why" for me is; never mind the isolated tests, why haven't I come to prefer tubes in real systems? Please forgive me for answering my own question, I suspect it might have more to do with the speakers that I seem to prefer. Whatever charms tubes have (oh yeah, I can appreciate some of them) might be outweighed by the compromises that the speakers that they need to be paired with have. In the end we listen to systems, not components, and especially not isolated tests. Of course that is not to suggest that isolated tests don't have merit, in proper context they absolutely do.
pubul57
3,712 posts
 
Unsound, I think you hit on it, some speakers simply need SS to be driven properly ans tube amps will not perform well with them - usually amps with low nominal input impedance, but perhaps more importantly speakers with big swings in impedance at various frequencies - I think Theil speakers might be like that. Like the question of passive versus active preamplification, the system context makes all the difference, and not necessarily the inherent attribute of the amp, preamp, or anything else.
atmasphere's avatar
atmasphere
11,942 posts
 
Unsound, for your answer:
http://www.atma-sphere.com/papers/paradigm_paper2.html

Tubes will not drive all speakers 'correctly' and of course there are speakers that cannot be driven by transistors.

However I am pretty sure that this thread is assuming that the speaker in use is not a variable for the purposes of this conversation.
unsound
7,333 posts
 
Atmasphere, thank you. I read the link again, it's a good read and worth re-reading. The link points to feedback as the anathema to good sound. I tend to agree with that, but, as the link suggests the lack of feedback is not exclusive to tubes, and doesn't suggest to the amount of feedback that becomes objectionable and/or might provide an appropriate balance of pros to compensate for the cons.
Perhaps better for another thread, but, I could imagine a digital processing ss amplifier that could use feedback and then correct for the time lag.
While the OP's speakers might seem to be better suited to tube amps, I think the blanket promotion of the notion that lower powered tube amps sound louder than lower powered ss amps is misleading, and furthermore that the premise of choosing a system around amplification is misguided. You of course, may disagree.
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