"The ASP1000 module is worst in this respect being what....about 1/2 db down at 20khz w/4 ohm load?"
Magfan - you're right (just checked datasheet graphs) but 8 ohms have too much down and up by 1/4dB starting in less than 10kHz. My Rowlands 200ASC is a little better - it dives down about 1/4dB but comes back to 0dB at 35-40kHz. Phase shift over 20kHz is also smaller - effect of higher carrier frequency.
Mapman - I was turning everything OFF but now I have Furman Elite 20 PFI conditioner with non-sacrificial over and undervoltage protection and keep everything ON all the time. It clamps at much lower voltage than traditional MOV protection.
Magfan - you're right (just checked datasheet graphs) but 8 ohms have too much down and up by 1/4dB starting in less than 10kHz. My Rowlands 200ASC is a little better - it dives down about 1/4dB but comes back to 0dB at 35-40kHz. Phase shift over 20kHz is also smaller - effect of higher carrier frequency.
Mapman - I was turning everything OFF but now I have Furman Elite 20 PFI conditioner with non-sacrificial over and undervoltage protection and keep everything ON all the time. It clamps at much lower voltage than traditional MOV protection.