Bad Presence pot on .50 cal

[Hangar18]

I recently acquired a .50 cal + and am only somewhat impressed. The presence knob doesn't change the tone at all so I pulled the preamp and all the wires look good. I'm guessing the pot needs cleaned or replaced. Is mesa the only place I could buy one if thats what it needs? Could it be the resistor on the pot? Thanks.

 

[ams2ek]

If I rember right with your master volume set low you will not hear presence adjustments. Try turning up the master then adjust the presence. It was either the master or lead master if set too low you wont hear any presence adjustments.
Rick

 

[Hangar18]

Thanks. It works, it's just not a very powerful control. This amp seems dark all the time.

 

[scottcrud]

Somethings wrong with it then. Mine makes a BIG difference . It gets real sharp the higher it goes.

 

[jimmy9]

Hi guys!

I have another sort of problem with the presence pot on my 50cal+. It works as another master volume. Could it be a bad 005 cap at the pot?

 

[adamlanghans]

Perhaps someone modded it into a variable Negative Feedback Resistor?

 

[jimmy9]

Well I lurked into the chassis and everything seemed normal... the cap is soldered tight. Think I'll replace the cap since it's dirt cheap, if it won't work, then we'll see what next.

ps. sorry for reviving a necrothread

 

[Roadifier]

Perhaps someone modded it into a variable Negative Feedback Resistor?

How would someone do that? I want to do that with my 50 cal +

Sorry for the old thread bump :lol: