Output power

Doing final measurements on an amp and thought this might be of interest.

This is one way to answer the question "How do you know the output power of an amp?".
Note: thermal dissipation in the power tubes (plate current * plate voltage) is not the right answer






FWIW, the C50-RT ("Bob") into an 8 ohm load with a 440Hz (low A) input starts to compress at about 25W with max clipped power at about 43W when running a pair of 6L6GC

And yes, I need to clean up my bench.

 

Thanks John

Digital stuff is nice, but an old analog (with the mirror for parallax) is really tough to beat. This one goes to 200W and claims 1/4% accuracy up to 1KHz, 1/2% accurate to 2.5KHz.

 

Autotransformers are easy to come by, keep an eye on Fleabay. But for test meters (excepting general purpose DMM, in which case it's Fluke, Fluke, and Fluke) the old high quality analog meters from Weston, Avo, Simpson, etc. make current stuff look like garbage. The meter movements for current production stuff tend to be pretty sloppy. I can only assume because most folks want digital -- but on an analog device you just get a better feel for what's going on in some cases.