Let me start by saying that I am NOT an expert. I am building a step attenuator to run a passive preamp for my VTA high gain ST70. I have read quite a bit about choosing resistors and matching the output impedance of the preamp to the input impedance of the amp. The most common recommendation that I have found is a ratio of 10 to 1. Since my amp has an input impedance of 270k ohms, I am selecting resistor pairs (ladder T attenuator) to give an output impedance of around 27k ohms. This is fairly easy to do at lower attenuation but at even mid levels of attenuation I am getting really high resistor values, particularly for the input resistor. For example at 25dB I have an input resistor of 500k and the resistor to ground of around 29k. The input resistors start going up dramatically for higher attenuation. Am I worrying too much about matching at the 10 to 1? In fact at 45db the input resistor is 4.9M. Is all that resistance going to muddy the sound? By the way, my source is a CD player with 2v output.

Thanks for any advice. Please let me know if I am way off as I am new to all of this.

Thanks for any advice. Please let me know if I am way off as I am new to all of this.