Which HQP Filter are you using? [2015-2023]

[andybob (Andrew Cox)]

This response by Jussi in another thread sets out more detail about bypassing filters in a typical DAC:

What do most people use HQ player for?

Just to explain some major differences between how typical DAC chips work vs how HQPlayer processes signal… When RedBook content is played, typical DAC chip processing path looks like this: [2x 63-tap FIR] -> [2x 31-tap FIR] -> [2x 15-tap FIR] -> [16x sample&hold] -> [3rd order sigma-delta modulator] So after first stage rate is 88.2k, after second stage 176.4k and after third stage 352.8k. After that point, every sample is repeated 16 times (sample&hold aka zero-order-hold) reaching 5.6 MHz …