Problem on rpi with adafruit speaker bonnet

Running amixer get PCM I get:

```bash
Simple mixer control 'PCM',0
  Capabilities: volume
  Playback channels: Front Left - Front Right
  Capture channels: Front Left - Front Right
  Limits: 0 - 255
  Front Left: 51 [20%]
  Front Right: 51 [20%]
```

which doesn't parse with the regex reInfo