Guitarix team http://www.guitarix.org/
5 Pedalboards using it

GxHighFrequencyBrightener

Plugin screenshot

A High Frequency Brightener

Control Default Min Max
INTENSITY 0.50 0.00 1.00
VOLUME 0.50 0.00 1.00
http://guitarix.sourceforge.net/plugins/gx_hfb_#_hfb_ v.1:28.3-24