I have a different Outlaw amp. On the outside of the original box there is a check box for either a 110v or a 220v version. In such a case, there may be a way to change between each version, or each version may require a different mains power transformer.

Other than changes within the amplifier, an external transformer may usually be used. One of the small, rather inexpensive, voltage ‘converters’ for devices such as hair dryers or electric shavers would not usually be appropriate. Be sure that the transformer can handle at least a bit more than the maximum load you intend use.

If you are not only going to change from 100v to 220v, depending on your destination, you may also be changing from 60Hz to 50Hz. A transformer will change the voltage but not the AC power line frequency. While quite a lot of devices may be safely and properly operated in this manner, there are a few electronic items that will not function properly. Outlaw will have to tell you if your 7100 may be operated via a transformer such that the 7100 will receive 110v at 50Hz.