Input Impedance?

[dkenin]

Hey guys,

I was just wondering what this parameter did in the "Input" block where the gate is located. I was having a high pitched shrilly squeal coming from my guitars when I turn the volume up on my Atomic CLR. When I moved the rotary knob toward the last option (22micro +) I noticed it went away. What exactly does this do? It got rid of my problem, but why? Is there something else it will be doing to my guitar tone as well?

Thanks,

Dave

 

[AdmiralB]

It 'virtually' loads the input signal, sort of like using smaller and smaller-value pots in your guitar. The sonic result is primarily (there are others) attenuated treble, which is why your microphony is reduced by turning it down.

 

[dkenin]

It 'virtually' loads the input signal, sort of like using smaller and smaller-value pots in your guitar. The sonic result is primarily (there are others) attenuated treble, which is why your microphony is reduced by turning it down.

Thanks for the answer! What do you mean by value pots? Like a lower volume hitting the front end of the axe? Or is the capacitor like a high pass filter?

 

[Sixstring]

Thanks for the answer! What do you mean by value pots? Like a lower volume hitting the front end of the axe? Or is the capacitor like a high pass filter?

He is referring the the resistance value of the volume and tone pots in the guitar. 500k, 250k, etc...

 

[yek]

Input impedance

 

[FractalAudio]

You are experiencing what is known as "tweeter squeal". This occurs due to magnetic feedback from the tweeter into your pickups. Changing the input impedance shifts the high frequency resonance of your pickups and reduces their frequency response. This will lower the loop gain which causes the squealing to stop.

The best solution is to move further away from the monitors.

 

[rdnzl]

It 'virtually' loads the input signal, sort of like using smaller and smaller-value pots in your guitar. The sonic result is primarily (there are others) attenuated treble, which is why your microphony is reduced by turning it down.

Just a friendly nitpick:
It is actually NOT virtual but very much real and physical. Axe FX II does it by switching in actual resistors and capacitors on the input circuit.