Game Boy lineout, a.k.a. Prosound mod

I soldered a TRS 3.5mm audio jack to the direct line level stereo output of my Game Boy DMG. Wow does it sound richer and beefier (technical terms)! Still responds to the volume pot and I may have recorded this a bit hot.
Audio recorded from Game Boy to Alesis mixer. I didn’t change the volume dial on the GB when I swapped the cable between outputs, so the volume difference is inherent between them.

I followed this page for guidance: