Electronic – arduino – Why does the AY-3-8910 sound so distorted

I'm building a circuit driven by an Arduino UNO that controls a AY-3-8910 programmable sound generator.

The AY has three pins labeled Channel A, B and C. Each output is an independent sound channel.

I am piping the audio through an LM386 which then drives a small PC speaker.

When I run a single channel, it sounds pretty good. But each time I mix another channel, things start getting really distorted.

I've built this on a breadboard in the past and it sounded great so I don't know what I'm doing wrong this time.

Below is a crude schematic of my circuit. I didn't draw the LM386 because it's the same with or without it and I never used it before.

Any ideas how I can cleanly mix these signals? I don't remember doing anything in the past other than literally connecting all three channels together.

I can provide more schematics and/or videos or pictures too. This is driving me nuts. So I'm hoping someone out there has worked with this sound generator in the past that can provide some insight.

Thanks.

^{simulate this circuit – Schematic created using CircuitLab}