Is it possible to turn my console´s LF bell into a shelf?

[Soul One]

Hey guys,

I have a A&H GS3 mixing console and was wondering if it would be possible to mod it so the LF bell becomes a LF shelf?

 

[gyraf]

..dunno.. Maybe try shorting C18 (100nf) and see what happens..?

Jakob E.

 

[L´Andratté]

It is a so called Wien bridge filter but could be a standard Baxandall configuration with removal of c17 and the freq pot (+series resistor), if you lose those components and adjust the other a little, you should get standard shelf but without freq tuning. 
But the original version is much more useful (imo).

 

[Soul One]

Many thanks for your replies, guys.

If I´d be loosing the frequency adjustment this would be a bummer.

 

[abbey road d enfer]

It is a so called Wien bridge filter but could be a standard Baxandall configuration with removal of c17 and the freq pot (+series resistor), if you lose those components and adjust the other a little, you should get standard shelf but without freq tuning. 

In a standard Baxendall, the LF branch goes to the inverting input, and the HF branch is isolated with a resistor that defines the cornetr frequency in conjunction with the LF capacitor(s). Connecting the LF branch to the non-inverting input, as a degraded version of the Wien bridge topology results in two things:
-It inverts the rotation of the Boost/Cut pot (CW becomes Cut, CCW becomes Boost
-Very reduced amplitude of Boost/Cut

But the original version is much more useful (imo).

I agree.

 

[abbey road d enfer]

Many thanks for your replies, guys.

If I´d be loosing the frequency adjustment this would be a bummer.

A standard Baxendall can be easily modified for variable frequency.