If the problem is sagging voltage, you could potentially try something like this Equitech product that they are selling on closeout. Though I would call them first to see if they think it could solve your problem. Product description:
Model 1R-J - Identical product to Model 1R but with 8% voltage boost. Originally these units were intended for use in Japan and the Caribbean where common AC power is 100 Volts and where North American gear designed for 115-120V is to be used. They are also very useful in areas of the US where the voltage is low. (<110V-115V) They will correct low voltage situations and output a nominal 120V. They are not to be used in North America where the local line voltage is typically in excess of 110V. If this recommendation is not followed, tubes and power supplies will be short lived. However, these "J" units can be very useful where lower supply voltage (100V - 110V) is all that is availble and North American equipment designed for 115-120V power is to be used. Special Clearance Price - Only a few left - $500
BTW, $500 for an Equitech product is a steal.