How important is the N/S ratio for an amp?

[Sunny98007]

Is N/S ratio the key factor for an amp?

 

[RobinKidderminster]

S/N is more important imo.

 

[MajorFubar]

Is N/S ratio the key factor for an amp?

No. What's key is what it sounds like. And while specification-sheets tell you part of the story, they don't tell you it all. There must be measurable qualities about an amp which are directly related to how it sounds, but I can't tell you what they are. It's certainly more complicated that the simple specs shown at the back of an amp's manual such as Wattage, S/N, THD and damping-factor, otherwise all amps with similar values for those specs would sound the same.