"I purchased a whole system that included an ETA power conditioner rated 20 amperes. The plug will not plug into a standard wall outlet because one of the pins is rotated 90 degrees. My house and almost every house on the planet is set up for 15 ampere plugs and I assume it is not a good idea to just replace the plug with a 15 amp version. What should I do to use it?"

Well, hold on a minute. Before someone accuses us of being too colloquial, let me remind you that nowhere near every house on the planet has 15 amp service. That said, you can assume most houses in the U.S. (our target audience) do. You are correct that a 20 amp plug has one pin turned sideways. This is done specifically to keep them from being inserted into a 15 amp plug. You can buy 20 amp wall outlets. They will accept both 15 and 20 amp plugs. You can recognize those by observing that one of the slots looks more like a sideways "T," which is how they accommodate both types. Of course, the reason you have a 15 amp plug is almost certainly because it is connected to a 15 amp circuit breaker and probably, but not necessarily, because the wiring between them is only rated at 15 amps. This leads us to our first possible solution.

Before we go on, please be advised that we are not electrical engineers and do not know the electrical and fire codes covering your geographic area. Anything we tell you should not be attempted unless you know what you are doing and/or consult with an electrician. We are not responsible for... blah, blah, blah. Okay?

If you can determine that the house wiring in question is capable of handling a 20 amp load you can probably just replace the circuit breaker and wall outlet to accommodate your power conditioner, This is the best solution.

You can simply build or buy an adapter to go between the 15 amp outlet and 20 amp plug. This isn't the same as getting real 20 amp service to the outlet, but is relatively safe. If the device tries to pull too much current your 15 amp breaker will trip and remove the power. Of course, in that mode you'd have to ask yourself what the benefit of the extra 5 amps you paid for is.

If necessary, you can have your wiring for that circuit updated, or a new circuit installed to accommodate the 20 amp load. If this is too difficult you could also install (or have installed) a new 20 amp circuit closer to your main breaker box and then use a 20 amp rated extension cord to deliver that power to your studio location.