Ah cool thanks for the info. I was hoping it might be a bit more advanced than ‘turn left for dark, turn right for bright’ type HP/LP
E.g. the Strymon Timeline combines LP and HP filter controls for a really cool range of tones.
From the manual:
‘FILTER: At minimum setting, the Filter Function provides a flat full-bandwidth response. As you turn the knob up, the repeats get progressively darker. Around 12:00, the filter is voiced to give an analog delay EQ curve. The darkest repeats occur with the Filter knob between 12:00 and 2:00 in these machine types. As you continue to turn the Filter Knob, the low end is progressively reduced, and some highs are added back in to create an EQ curve similar to that of a Tape delay when the knob is at maximum position.’