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Building a single channel variable U-Pad

I read up on pads of various kinds, and I want to design a single channel variable pad for use between a microphone and the preamp when recording drums. The preamp in question is the channel preamp of the RME Fireface 800, which has an input impedance of 2k. Here is what I want to do. I will build an external enclosure with XLR in and out mounted to it.

-30 dB cut box - stereo signal

Hey all!

Recently I got a diagram from an audio technician at a company telling me how to make my own -10 dB cut and -20 dB cut stereo box. But now that I made them did I realize that I need one single box with around -25/-30 dB cut. I can see from the numbers I got from the technician that it's not just doubling the ohm numbers to go 10 dB extra.

Determine the cut off frequency of any filter formed from output impedance and input impedance

Say you have a piece of electronic equipment which has an input impedance of 1Megohms, and an input capacitance of 10 picofarads as determined by a ceramic capacitor across the input resistor. This obviously creates an RC impedance filter which will act on any AC entering the device.