Presence

[waves]

Ok i was playing with my amp and while i can hear what the presence knob does i wondered what it actually does technically.

Anyone know?


(dunno if this is the right place for this thread)

[Twinfan]

It's linked to the power section of the amp, and is related to the amount of negative feedback that's pumped back through the power valves.  This basically tightens or smooths the sound out by cancelling out certain frequencies at the high end.

Presence = 0 gives max negative feedback, and the tightest and smoothest sound

[gwEm]

you can imagine it as a sort of 'attack' control

if you set your amp's treble control low (like at 1), and use the prescence control to adjust the treble you get a slighty different upper frequency voicing, which can be nicer sometimes.

[AdamB]

straight from my egnater manual

(this is density too)...

These knobs (presence and density) provide bass and treble boost in the poweramp section of your mod 50. Similar in effect to the loudness contour on your home stereo, at low volume, fullness and clarity is enhanced. These powerful controls should be used sparingly at high volumes. At higher volumes, if overused, the sound can get 'brittle' or 'muddy'.