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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
emorrisiv
313 posts
 
This is a great thread. My personal experience as a trained musician and not a scientist is that class A has always sounded "bigger",more powerful and more accurate(I could also say "musical" but I don't like to use that term).
I remember back in the 70s hearing a (200rms) GAS Ampzilla with some Energy speakers. I wasn't moved.We then heard the same speakers with a little 10watt class A Bedini and it blew the Ampzilla away in every way. That was a learning experience that has always come back to me when I audition amps.I hear tube amps similarly to SS amps.
Could someone talk of Triode PP vs Ultralinear? Since they are frequently the same amp being able to work in either mode.

Now what I really want to know is will Ralph's M60 work with my Acoustats! (with zeros of course).

just having fun

e
davemitchell
253 posts
 
Yes Pubul57, the signal does have to fight its way through all of that copper wire, but as we have learned over the last couple of decades, the dielectric is as important as the conductor and air dielectrics sound the best in cables for much the same reason that a vacuum sounds best in amplification.

The less physically intrusive dielectric there is to block and distort the signal, the better.
pubul57
3,712 posts
 
Well, for whatever reason, tube amps sound better to me, and believe me I have tried several times to fall in love with an SS amp (all have been Class A)and they always end up going back and I go back to my tube amps. My speakers may have a lot to do with that, I'm sure with some SS would be the way I would have to go and tubes might not do quite so well in driving them.
unsound
7,329 posts
 
Atmasphere, I would really like to read that GE report in complete form.
atmasphere's avatar
atmasphere
11,803 posts
 
I've only seen snipets but its easy to prove if you have some very basic test equipment.

All you need is a sine/square wave generator, a small amp of any type, a VU meter and a speaker.

Set up the sine to drive the amp, which is in turn driving the speaker. Put the VU meter across the speaker terminals. Obviously you don't need a lot of power for this test. Set the sine wave to read 0VU on the meter. Now switch to the square wave and set it **without looking at the meter** to the same apparent sound pressure level.

What you will find is that with the square wave you are setting it somewhere in the neighborhood of -20 to -30 db to get the same sense of volume- less than 1/100th of the original power!

Square waves are composed of only odd-ordered harmonics. This is a very simple test, but it illustrates the issue very clearly.
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