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Why tube amps are rated so low, still don't get it

Hi Guys,

I am still very confused as to howcome tube amps are rated so low, and how to tell whether the amp will be able to power your speakers properly. In particular I am interested in the Shanling SP-80 tube amplifiers for my system. This is since I have the CD-T100 and I want to partner it up with the amp for the synergy. The amps are rated at 50W each (monoblocks). Is that enough? How do I compare it to a SS amp? I tell someone 50W SS and they laugh, but I say 50W tube and they call it a monster! I am still very confused!

Thanks for any help/explanation,
X
xenithon
bomarc
501 posts
 
50W is pretty hefty for a tube amp. Nobody can look at a set of specs and tell you whether a particular amp can drive a particular speaker. (All right, a 200-watter can drive horns.) There are too many variables. The only way to know for sure is to get them both into your room, and play them as loud as you are likely to ever want to listen with some really demanding (think orchestral warhorse) material. If it sounds good, it is good.
xenithon OP
130 posts
 
Hi There,

I'l be honest with you - Shanling is not available here. I tested out the CD Player when I was overseas and fell in love with it, so I imported it specially. The tube amps I will thus not be able to test.
marakanetz's avatar
marakanetz
5,473 posts
 
All we're trying to explain is delivered power to a visible by amplifier freequencies.
A noise contains all components of such audiable "visible" freequencies.

If we take a trivial sine wave 1kHz and feed to both 50W tube amp and 50W SS amp they will both deliver the SAME power to the dummy load(measured by true-RMS Voltmeter).

Speaking of the noise noise experiment we may assume all audio freequencies but far not all load combinations.
We also can apply the term of "visible" freequencies and in SS case they're much larger let's say at particular THD limit set for both experimented units.

Now, in your case when you're shopping for full-range speakers of medium efficiency... I'd have to say you'll only hear half of them with 50W of tube power. I'm not saying that you shouldn't shop for tube amp that HAS plenty of advantages to the SS but you'll have to shop for higher powered ones than 50Wpc.
You must also take a note that higher power tube amps have a higher-complexity power supplies and so with cost of parts and lower reliability.
I have a tube amp myself and it took me a while of research how to improve a reliability without loosing performance and I finally did it at once. I now prefere in bi-amp setup together with Sunfire Symphonic Reference unit fed trhough DIY balanced converter with adjustable gain -10 to unity.
It saves the tubes and brings me the best of both worlds of amplification FYI...
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