One thing you might want to consider is that if the Halcro preamp prefers to be plugged in directly into the wall, the conditioner that you compared it with is really not doing you any favors.
You could have the outlets mounted on the floor rather than the wall. You might also consider that adding another outlet on the wall isn't crazy- houses are required by code to have outlets, and people use them, even for stereos.
You could have the outlets mounted on the floor rather than the wall. You might also consider that adding another outlet on the wall isn't crazy- houses are required by code to have outlets, and people use them, even for stereos.