Stereo Amplifier fades out. My Sansui dolby pro
No that's how to describe a problem, folks - with details. Using internal FM as the source is always the preferred way of troubleshooting system-wide receiver audio problems (no cables or setting in the way).
Does the sound come on immediately with power and then fade or is there a small delay while the electronics stabilize, a click and then sound that fades?
The fizzle probably means something is rapidly overheating or a capacitor is malfunctioning. If both channels do it, I'd suspect a common power supply problem. Can't help much more than that.