RadioBOSS lets you use VST and WinAmp DSP plugins (dsp_*.dll), except ones that change the speed of a stream. You can also use an integrated DSP (e.g., Equalizer or Compressor).
To open the DSP manager, select the FX tab on the control panel:
To add a DSP, click the “+” button. To remove a DSP, click the “–” button. To change DSP parameters, use the configuration button 
.
To move DSP up/down, use the up-arrow/down-arrow button. DSPs are applied from top to bottom.
If you click the “+” button, all available DSP effects will be shown:
Check the Winamp DSP plug-ins and/or VST plug-ins check boxes if you want to use these plugins. To open the folder containing Winamp DSP plugins for RadioBOSS, click “Plugin folders...”
Select a plugin and click OK. The plugin will be added to the DSP chain:
To turn DSP effects on/off, check/uncheck them in the list.
Please see this page for guides on installing VST or Winamp DSP plugins: https://www.djsoft.net/enu/support.htm