I would suggest starting with a dedicated circuit on your fuse / circuit breaker box.
Secondly, in speaking with an amp manufacturer he said that most amps aren't designed to have a transformer placed before it in the form of a line conditioner so that could be one reason why some amps sound worse when plugged into the line conditioner - check with your amp manufacturer.
As an alternative, use a passive bi-directional filter type of line conditioner.
I use a dedicated circuit, and the Foundation Research LC-1 passive line conditioner and an active line conditioner by Equi-Tec which creates a very black background.
Secondly, in speaking with an amp manufacturer he said that most amps aren't designed to have a transformer placed before it in the form of a line conditioner so that could be one reason why some amps sound worse when plugged into the line conditioner - check with your amp manufacturer.
As an alternative, use a passive bi-directional filter type of line conditioner.
I use a dedicated circuit, and the Foundation Research LC-1 passive line conditioner and an active line conditioner by Equi-Tec which creates a very black background.