Presence knob

[MattPete]

Re: Presence knob

Another way to think of the presence knob is to compare it to where the tone stack occurs in the circuit. The tone stack occurs in the middle (fender, mesa) or end (marshall) of the preamp. So, turning down the treble not only removes highs, but it will remove the highs due to preamp distortion. The presence occurs in the poweramp. So, turning down the presence can not only can remove the highs that occur earlier in the chain, but also can remove highs due to poweramp distortion.

That's a simplification. NFB also has other effects.

 

[Pink Unicorn Horsey]

Re: Presence knob

Rather than describing the "presence knob" by electronic function (and I see no problem with that), I would rather decribe it this way:

I find the "presence control" could also be described as a "speaker axis knob". Use of the presence knob often simulates the difference between standing in front of the amp (lots of prescence)...and walking off to the side (less presence).

Frequencies above the the typical "treble knob" do seem to be the range of the "presence knob", and the these are the most affected by on-axis/off-axis positions.

Amplifiers have so many voices! There is no rule where the "presence knob" needs to be set. Many amps have no such control, and there are players who like it that way.

The presence control on my Sunn is the most powerful knob on the amp, besides the volumes. On my Mesa, I run it it about "3", but this amp has both treble and EQ sections too.

I like this non-technical description a lot, Sludgenutz. :bigthumb:

- Keith

 

[disturb]

Re: Presence knob

I have Marshalls, Mesa's, and a Diezel. My Presence knob on all of them is between 10:00 and 12:00. Seems to be the sweet spot.