Out 1 by itself is limited to 20v peak to peak.
Boosted port using 20v and inverse+sync provides up to 40v peak to peak.
When you double the voltage, you square the power.
Other than this, there is no difference in output frequency wise.
Given that the PEFM coil was original driven by the SC at a fixed frequency of 100 Hz and at +29VDC which equates to 58v peak to peak, you will want to try and keep it boosted.
If you don't have a boost, while at 20v peak to peak, it may still offer some therapeutic effects.
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