Amiga 1200 Rev 1A Distorted Audio Output - Part 1

I've been playing the Chiperia #7 demo from Revision 2017 on the Amiga 600, which sounds fantastic.  The audio from the Left & Right phono jacks on the rear of the Amiga connects to the RGB SCART input connector on the rear of my good old Sony CRT television. 

There's likely very few people playing this demo on real hardware, especially from an actual floppy disk.  It's a similar feel to playing records ("Vinyl" in modern speak), where taking the time to write the disk and watch it load adds to the experience.

When I tried playing the same demo on the A1200 (Rev 1A motherboard) the audio level was significantly higher and the audio quality seemed distorted and over-driven.

There's a nice Youtube video discussing a known issue with Rev 1A motherboards where the audio opamp feedback resistors are too large and should be replaced with a lower value, thus decreasing the gain.  I'll try this out and post the outcome.  This post captures the current A1200 and A600 audio as a benchmark for before & after comparison.

Before, A1200 (sounds terrible!)

For reference, A600 (sounds great!)