Recording EVP is really very simple. You do not need any fancy or expensive audio recording equipment. You can easily record EVP using any audio recording device, whether that device be a cassette tape player-recorder, digital voice recorder or even the recorder in your smart phone. Although I personally would be reluctant to use the recorder in my smart or cell phone simply because it is specifically designed as a telephone with added features. And I absolutely do believe that the circuitry within such a device could lead to some possible audio contamination.
If you’re going to use a cassette recorder I would also suggest that you use an external microphone, as the microphones that are built into these devices could pick up the internal sounds of the mechanism itself and lead to some false positive EVP. It is also advisable to use a new tape, fresh out of the box, each and every time you do any EVP recordings. The use of an old tape, even though it may have been erased may have some residual sounds still imprinted upon it. This could also lend itself to sounds that may seem paranormal when they are nothing more than remnant or residual sounds.