Tube Amp. Power ratings


I'm a solid state guy intrigued with tube setups....Is this like everything else in Audiophilia, Eye (or ear) of the beholder? ....Would you always have a tube pre-amp with tube amp? In general terms how do tube amps differ? Warmer?...mellower....And what about the output ratings? The tube ratings seem much lower than SS...Is that the nature of the beast?....
kippster
>>The pwr. of tube amps decreases rapidly once the spkr. impedence deviates from the output tap being used<<

Not true. In the case of a 12 ohm load connected to an OTL amp, for example, the output power actually increases.

Conversely, the power output of a solid state amp decreases as the impedance increases.

The door swings both ways.
In general you will be noticing more detail with a more relaxed presentation with tube gear. As you noticed, power is harder to make with tubes so they are often less powerful for the money. You have to use a speaker that is designed for tubes- tube amps tend to make constant power with respect to load rather than constant voltage of most high quality transistor amps. This appears to be a matching issue, but it is more than that, take a look at

http://www.atma-sphere.com/papers/paradigm_paper2.html

If you use a speaker intended for tubes with a transistor amplifier, you will get tonal aberrations just like you will if you use a tube amp to drive a speaker intended for transistors. But overall, if you have a setup where the speaker is optimized for the tube amplifier, the presentation will be more lifelike and musical, as tubes in general obey more of the rules of human hearing than transistors do. Its something that you hear right away- its not subtle.
I've seen 20 year old amps running on original tubes. Heck, I've seen 40 year old tube amps running on the original tubes. In any case, I wouldn't worry too much about tube costs as a miantenance issue, but if you're coming from the SS camp, it should be a consideration.

I've seen sytems with SS pre's and tube amps that were great. That being said, if you like tubes you will likely end up with a tube pre and tube amps as they have similar attributes. Tube pre with SS amps is both popular and helps with tougher speaker loads while adding some tube magic.

In any case, if you buy used to try, you can almost always get the same money back out that you have into the piece.

My persoanl preference is to have tubes everywhere, but also remember not all tube amps sound the same and some amp/speaker combinations will be a problem as mentioned earlier. But oh, the fun of the journey!

And, of course you can listen in the dark and enjoy the
tube glow.

RFG
OTLs are an exception to the rule being designed for 8 ohms or greater. These amps are virtually useless w/ most 4 ohm spkrs of which there are many more on the mkt than 14/16 ohm spkrs.