The SUBPAC is widely compatible with anything that has a line or headphone out. This means you can use it with media players, computers, bass guitars, game systems, and pro studio equipment. It is not compatible with outputs on amplifiers that are meant to drive speakers. If you are using it with headphones that require more than 32ohms (most headphones are under this limit), you will get the best performance by using a matching high impedance amplifier separate from the SUBPAC.