OK, who fixed that standard, is there info on it? and who uses it? I did a quick browse of the big brands. Yamaha was quite thorough with many power figures, rated output power, effective max power, max power 10% THD, etc, this obviously give confidence you know where it's tested. but most other, Sony, Schiit, McIntosh, etc have no THD metric for max power, Should we then assume that they used that method? Me my first assumption was that if I don't see any information on where it's taken, I was probably not in the linear zone nor at "THD equivalent to 250 mW", I was assuming they would cherry pick a point that make the number bigger. It is good news if it is now standardised across the industry, and if it is indeed the case, That's also the number Amir should measure and publish, not best case THD, but I was not aware of that and I don't assume this when reading specs. Do you? I've seen 1% THD a lot, or 10% or nothing. If it is as you say the standard, then no info should just mean that. Does it?