How should I set the Presence switch on Riverside?

Riverside’s PRESENCE switch tailors the highest frequencies of the pedal’s output signal for connecting to a wide variety of amplifiers with different tone characteristics.

• The minus (-) position, provides clarity with a controlled top end that works well with many amps that have a brighter voice or extended top end character.
• The enhanced (center) position extends the top end to allow for more sizzle on high gain tones. This works well with amps that have a warmer voicing, or if you want enhanced detail in the uppermost frequencies.
• When plugging directly into a power amp, or into the effects return of an amplifier, the plus (+) position further increases high end detail that may be required. The plus (+) position will also deliver extended high end detail to the darkest amps.