Audio volume decreasing

Lately I've been playing with the audio circuit of my pc engine cd interface unit (briefcase model). With the help of tiido I discovered that the system generates pcm sounds internally in the ifu (interface unit). Without modifications the pcm sounds too loud and drowns out the cd audio. I found the source of the pcm audio (again thanks to tiido), but I havn't been able to decrease the volume of it. I tried putting a resistor in series up to 100k ohm, connecting a pull down resistor both at the source and after the first resistor in the circuit to create a voltage divider. The voltage divider idea did decrease the volume but sounds like it loses a little audio quality when I do that. I'm open to suggestions. My next idea is to find the cd audio traces and look for resistors to weaken on that part of the circuit instead.

If the D-A converter of the ADPCM circuit uses a simple R2R ladder, then putting in high-resistance parts might override the weaker resistors for the LSBits... that's just one guess. How about adding a diode or capacitor as a buffer first?

Maybe buffer it before the voltage divider?

So a cap followed by a voltage divider? Okay I can try that.

The problem is likely loss of right DC bias with your voltage divider.