I have had experience with a ton of amps NAD,Marantz, Mcintosh,Einstein,Electrohome,Yamaha,Tecnichs,
Ayon,Leo Research,Bryston,Meitner,Coda TS,15,15.5 and the S100,
The S100 tops the list. It's pretty close to the best of the tubes and Iam not replacing tubes every 1600-2400 hrs