Power cords to the same outlet

A 15 amp circuit at a nominal 115 volts has 1725 watts of available power. Compare that against the maximum operating power required by the 2 amplifiers. If your operating power requirements of all connected equipment is nearing 1500 watts you want to seriously consider adding another circuit to prevent voltage drop problems.

With monoblocks there are some who favor putting them on two circuits. Each one on opposite sides of the mains breaker. Supposedly this setup aids in canceling common noise. There are ways to simulate this setup if you want to see whether it's benefical in your situation. My method requires you know how to use a voltmeter however.

As Sean notes above there are potential problems to adding additional supply lines to your system, and is why I always advocate simulating a proposed additional line(s) setup for those who need/or want to try. There's even more potential problems with AGG's setup.

For starters it violates the National Electric Code which requires seperate a neutral (white) wire to the neutral side and seperate ground (usually bare or green) to the ground connection of a 115 volt outlet. The reason for this is to avoid the dangerous potential of a floating ground.

AGG, if your lines breaker is a double wide unit with a common lever, the two lines are most likely out of phase with each other. That's the normal way to get 230 volts in a common residential system. Don't even think of putting one of these lines on a different breaker (to create a common phase supply). You risk creating an extremely dangerous situation where 40 amps can travel thru a very undersized wire.

Like other posters to power related postings on this site: If you are not clear of the code requirements for a safe installation. Hire a licensed electrician for his knowledge.