SNR on tube amp detail?

I've never seen much discussion of links between S/N ratio's on tube amps and sonic qualities. Is it that wpc, topology and tubes make a bigger difference? I've noticed several well-reviewed and pricey amps with snr around 85db.
on tube amps the snr lower than on ss amps. on analogue phonostage it is allso lower than on cd-player
snr isn't only variable to consider amp.
making higher snr often caused by sacrifices of amp's performance such as increasing global negative feedback and decreasing input sensitivity. cheap IC-based amps will have better snr than tube amps, but that doesn't mean that they will sound better.