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Is there a difference between a high pass filter with an op amp and a high pass filter without one? Answered

I'm trying to modify a guitar effects pedal of mine to remove some squeaking and decided that a highpass/low pass combo with some potentiometers to modify the highpass and low pass points (since my pedal emits squeaking at different frequencies on different settings) and I was wondering if I should use a high/low pass with an op amp, capacitors, and resistors - or just a simple resistor and capacitor filter. Does anyone know if either configuration is a detriment to sound quality?

2 Replies

steveastroukBest Answer (author)2012-04-13

Its difficult to make a filter as flexible or as sharp as an ACTIVE filter.

Use decent op-amps and there is no degradation of the sound, if the thing's driven properly.

It sounds like you need to look for "parametric filter" designs.


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iceng (author)2012-04-12

They are basically the same except you can not easily add pots to a straight high-pass, 
However you can with an Op-Amp because that has gain.
And there is no signal loss when using an Op-Amp, even with pots.

Walter Jung has a very good book on filters if you go to Amazon,


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