Does anyone have a resource for what a normal running disco should sound like? I developed a hum from the engine bay, when I started listening to various things with an extension I realized I dint know what "good" sounded like. Specifically seems to be coming from either the alternator or the AC. Only present when I have pressure on the gas pedal. Driveshafts replaced with grease-able ones 3k ago and have been professionally balanced, just to get that out of the way.

Edit: The first thing I did was replace the serp belt, tensioner and rollers