<HTML>Terry,  I was taught that the stability was not an issue,as you were goiung to change it again anyway. I get them close,and move on,unless I can tell it is really changing. On the treble I have found to tune sharpe ,in relation to how flat the note is,or how fast the lights are spinning,I will go that far in relation above it.It works for me anyway.   Good tuning Hazen Bannister</HTML>