When you save a preset it will be initially saved at the end of the list of factory presets.  If you save it utilizing our tagging system you can access it via the tags you saved it with.  The physical preset .nka file will be stored in the Signal Presets folder located here: SIGNAL > Data > Signal Presets

Please note, once you restart SIGNAL a "SCAN" of the presets may be required to pull up your recently saved presets.  This option is only available on NKI restart, and can be found on the preset select page in the preset viewer window.