If you didn't see any harmonics in a -130 dB noise floor, that is also an excellent result. My question was not about chasing SINAD but trying to understand if there is a weak spot in their design. I still doubt that it is really full class B, though.No, I cannot measure that low. Just down to -130dB. Anyway, I find such race pointless, bringing nothing but issues we can see here. But it sells, the SINAD sells to certain group of customers, regardless other parameters.