presence knob says shhhhhhh

Express, Liverpool, Rocket, Dirty Little Monster, etc.

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HobbswheresCalvin
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presence knob says shhhhhhh

Post by HobbswheresCalvin »

Although the presence pot does seem to add presence to the sound up until 80 percent of its full load, it brings in alot of excess hiss after that, when you turn the pot there is an audible shhh... It sounds like a broom sweeping the floor. Any ideas?
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fishy
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Re: presence knob says shhhhhhh

Post by fishy »

The presence pot has DC on it hence the noise when you adjust it.
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HobbswheresCalvin
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Re: presence knob says shhhhhhh

Post by HobbswheresCalvin »

Good, bad?
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Structo
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Re: presence knob says shhhhhhh

Post by Structo »

DC on a pot can make it sound scratchy or dirty when you adjust it.

On the Presence circuit this is common and not really a problem since it isn't messed with a lot.

On other pots you shouldn't be getting DC and if you do it's probably a leaky cap preceding the pot.
Tom

Don't let that smoke out!
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HobbswheresCalvin
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Re: presence knob says shhhhhhh

Post by HobbswheresCalvin »

Ok cool. Is there a way of getting rid of it. I am wondering if it is causing the hiss i am getting as i turn up the amp
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fishy
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Re: presence knob says shhhhhhh

Post by fishy »

Lead dress - makes a big differnce on the feedback wiring.

Shielding the feedback wire is an option also.
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HobbswheresCalvin
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Re: presence knob says shhhhhhh

Post by HobbswheresCalvin »

I resoldered the resistor to the lug and did a better job with the heat shrink, decided to heat shrink all the way up to the lug. Ill check it out tonight, thanks.

I think im going to turn the presence knob into a resonance knob later tho anyway
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