Power Conditioner

I have Furman Elite 20PFI and like it very much.  I bought it used for about $650.  It has very tight non-sacrificial over/under voltage protection and I believe that it filters HF noise well.  My previous amp had plain unregulated power supply and did not suffer any loss of dynamics when plugged into it (high current bank).  I have whole house spike protection, but Furman already turned off circuit breaker few times.  When it happened I noticed bulbs got brighter for a moment.  Now with double protection I feel very safe.  Whole house protection is a must since everything these days is electronic, including appliances and even light bulbs, but Furman gives me extra protection for expensive gear.