Measuring amp power.

twoleftears,

Thank you!!!!!!!!!!!!!!!!!!

https://www.stereophile.com/content/cary-audio-design-cad-300sei-integrated-amplifier-measurements-part-3

To all the responders, Thanks for your input. I don't think it was a stupid question, but some might (and obviously) disagree. 
 I actually love my amp in my current set up and have no intentions of upgrading. Merely a case of curiosity.
Btw, the amp is a Cary CAD 300-SEI. Over time I rolled the 6SN7s with NOS tubes from Brent Jesse. Replaced the 300Bs with AudioNote ones. It sounds entirely different than with the new Russian tubes originally provided.
The reason for my curiosity is that Cary specs the amp at 15 WPC. Most of the other 300B amps I see are spaced at 8-9 WPC including the Elekit TU-8600 I run in my second system.
My main system with the Cary has 97Db efficiency speakers. Even at relatively loud levels , the system is never challenged nor have I ever been aware of any clipping.
Thanks again to all. Please stay safe,

A

Type in your amp name model number followed by “review” or “on the bench” “bench tested”

 good luck

I mean, yes, anyone could given the correct gear.  A signal generator, distortion analyzer and power resistors adequate to the task.

Poke around the Stereophile web site.  They publish how they test and recently had an article on the amp pre-conditioning (i.e. pre-heating) requirement. 
Anything short of this is just kind of hackery.

Well honestly that is rather pointless. The problem is what I said, there are lots of ways to measure power. The industry standard RMS is rather complicated, and involves preheating with a load far higher than any you are likely to ever do, to get the amp good and hot, then with prescribed test tones and wave amplitude measurement. Then too specific THD and IM distortion levels must be specified. All because 50-60 or more years ago before we had these standards everyone was measuring a different way, a lot would quote unrealistic peak power at some frequency for a millisecond, stuff no one has done for decades but we all continue to pay the price today in the form of heat sink overkill and a lot of other crap no one even knows about because no one knows the history.  

All to arrive at one of the most meaningless numbers in audio: how many watts an amp puts out. Very nearly totally irrelevant. As anyone who listens to something like a 20 wpc Raven tube amp and a 200wpc ss amp side by side will immediately realize. Don't tell them and they will almost certainly say the Raven is the 200 watts, the ss is the 20. 

The simplest answer is stick a volt meter across the outputs while playing music through your speakers. You will have to do some math to convert the voltage reading to watts. Volts times amps equals watts. You will want to factor in your speaker impedance. Etc. Etc.

I find the story of power and how we measure it a whole lot more interesting than the actual measuring which bores me to tears, especially since I understand fully the total waste of time it is, so you will have to excuse me, search around and look that up for yourself. 

millercarbon, just really curious. I use a 300B SET amp that I am very happy with. Just would like to test the manufacturer’s specs.

Thanks

There are lots of ways. Why? 

I can tell you NEED 500 watts of tube power.