Musical Fidelity using cheap selecter & volume ?

My ex MF amp, A1X,A100,A3 had these problem.sound "de de" when turning the selecter.
And Now, I'm using NuVista M3 , Problem occur again.Very bad contact selecter.
Hi Red:

Not quite sure what you mean when you say it sounds "de de." The problem that I have had with the volume knob and input selectors has been with the remote control. The remote controls are rather cheaply made and after awhile don't work. There are functions with the CE PRE24 that are remote only and it cost me $85 for a replacement remote. This is the only build problem that I am aware of.

Regards, Rich
Thanks for your response.
My remote function good and no problem.I mean when I turn the selector manually,distortion ,dede or sisi occurs.Have you turned the selector manually before ?