If the line conditioner has any provisions for under/over voltage, I wouldn't use it in conjunction with the voltage regulator.

If the voltage regulator does not have the ability to pass sufficient amounts of current instantaneously to satisfy the needs of the amplifier, which many do not, then I would put the voltage regulator on my alarm clock, not my system.

On the other hand, many line conditioners cannot pass sufficient amounts of current to satisfy the needs of many pieces of audio.

If you use both, the voltage regulator should be first in line from the AC outlet.

I would first call the manufacturer of both units and ask their advice on combining the two units.

Then I would plug in one at atime and listen to some demanding music to listen for the system struggling more with the unit in the AC line than when it is removed.

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