I know Marshall's presence control (on lets say a 2203/4 head) controls the negative feedback loop. Can someone please dumb the process down and explain how this works and effects the sound?
I always thought of the presence as the "sparkle" above the treble knob, but now I am hearing more complexity in what it does. Maybe my ears are just getting better (or worse) but I feel like the presence knob actually adds some sparkle and also takes out some upper mids somewhere....its definitely a well named knob as it seems to add presence in the mix, just as it should. I have basically left this knob on 5 for the last 6 years (why?) and have just now decided to turn it up some more....diggin' the sound but wondering about the technical aspects.
I have a general idea of how a passive tone stack works in the amp.....but the negative feedback loop thing is a bit over my head. Any help with understanding this would be great!!!
Also "Presence" is the best Zeppelin album so you know there is something going on there
thanks!!
