1. Contact for any purpose can use either the CS port or the High Power Port. These are the two middle ports on top line of 4 on the Boost.
The CS port will be slightly less apt to be felt during the program operation, but either will work.
There is a small resistor in the CS circuit to limit current when making CS. This is generally insignificant when using Contact because the body impedance is usually much greater than this resistor, so the effective difference should be very slight.
You can try the High Power Port, but if there is too much tingling, then change to the CS port.
2.There are also specific settings in the users guide to prevent the tingling, burning, or convulsions that can occur with lower frequencies. While the manual recommends to reduce amplitude for frequencies before 10k hz, I prefer to use 5k hz and occasionally 1k hz. I also tend not to use the recommended frequency limit of 20hz s this will completely block out anything below but these are the ones which cause the most irritation for people. Some lower frequencies are essential in the healing process. It may take some experimentation to find what is most comfortable.
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