Tube watts vs SS watts

[Sada Yairi]

IIRC, one tube watt equals 3 SS watts......so a 10 watt tube amp equals approximately 30 SS watts.

That doesn't seem right to me. Lately I've been playing around with two amps - a 5watt class A and a 15watt ss. The tube is significantly louder than the ss, so a 1:3 ratio doesn't seem right. I'm just not sufficiently versed with ss amps above 15watts to know what the 5watt tube compares to. Seems to me 5watt class A has to be on par with at least 25watts of ss.
At the same time, what you say about pushing the relative amps is certainly true. Pushing a solid-state is not pretty.

[Ch0jin]

That doesn't seem right to me. Lately I've been playing around with two amps - a 5watt class A and a 15watt ss. The tube is significantly louder than the ss, so a 1:3 ratio doesn't seem right. I'm just not sufficiently versed with ss amps above 15watts to know what the 5watt tube compares to. Seems to me 5watt class A has to be on par with at least 25watts of ss.
At the same time, what you say about pushing the relative amps is certainly true. Pushing a solid-state is not pretty.

Scientifically speaking, Watts are Watts. P=IV Apparent Volume is another thing entirely.

Whilst I don't disagree with anything here, and I think I've covered this in detail somewhere before, 3:1 is NOT a rule. It's just a quick reference to indicate a tube amp with the same power rating as a SS amp will usually sound louder. There are also dozens of other factors at play in making one amp seem louder than another.