411 Pro Help

JSmith

JSmith

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My 411 Pro has developed an issue concerning the tweeter. When using the tweeter it makes a scratching noise as if the tweeter is blown. Turning off the tweeter using the volume knob on the cabinet makes the scratchiness go away. So, I swapped out the tweeter to be sure. Soldered in the replacement tweeter and the same scratchiness was there so this leads me to believe that it's not the tweeter. Any suggestions? Would something maybe be wrong with the rear jack plate/tweeter volume control?
 
Hi Jeff,

Pushing the "ground lift" button solved my problem :-) It was exactly as you described.
 
I'll give that a shot. Don't think that's the issue however. Used the amp previously with a 211 Pro and no tweeter scratchiness, swap cab, scratchy tweeter. Amp isn't here so I won't know until Sunday.
 
Hey JSmith Might be the crossover,maybe a capacitor on it .check the whole xover & the wires .
 
Flo, I'm sorry I doubted you. :D You were right once again. Turned off the ground lift and the scratchiness was gone.
 
:-)
Cool! I remembered this because the sounds I got were more like a broken driver than static noise... And this was the solution...
 
Florin said:
:-)
Cool! I remembered this because the sounds I got were more like a broken driver than static noise... And this was the solution...
Click to expand...
Exactly what I was experiencing. Switched it off and cured the problem.
 
Educate the uneducated. What exactly is ground lift and how do you switch it on/off on the 411 cab? What are the advantages/disadvantages of having it on/off?

I have one but it's not in front of me right now...
 
The ground lift button is on the back of most amplifiers. In particular it's right next to the footswitch jack on the Warwick Tubepath and X-Treme amplifiers. In a nutshell the switch breaks the hum caused by a ground loop. Basically it will reduce or remove ground related noise when connecting equipment. Someone with a better a understanding of electronics can elaborate more or you can read up on it here. Ground lift - Wikipedia, the free encyclopedia
 
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