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. From there I will wire both the + and - contacts to the CW inputs of a 10k dual gang linear pot and using 20k as a shunt resistor. These values are chosen because 20k is 10x 2k and that should not affect the sound of the preamps and work solely as a signal reduction, which is desired. The pot value is chosen because if this were a simple unbalanced circuit, a voltage divider made from 20k and 20k would result in an even 50% reduction in signal level, which is fine for the application I think, but seeing as how the circuit is balanced, the R value turns into 1/2R for both conductors which carry signal to recreate the same amount of reduction. The output will be taken from the junction between the series and shunt resistors, which turns out to be the wipers of both pots and the shunt resistor will bridge both pot wipers. Am I on the right track here? Feel free to correct me or add anything you feel is relevant.