You could use a "Constant Voltage Transformer" (Good small one about $200) which would even out Voltage Spikes & Noise, assuming it supplied sufficient current for your AMP..
I utilize a single CVT for all but my Main Power Amps (which are plugged directly into a dedicated 20 amp line), the CVT provides the best results for Sound Quality from smaller current draw complnents
I utilize a single CVT for all but my Main Power Amps (which are plugged directly into a dedicated 20 amp line), the CVT provides the best results for Sound Quality from smaller current draw complnents