TopBarWidget already connects mapping_learned to _on_mapping_learned internally in set_midi_engine, so the external connection in main.py was both redundant and referenced a non-existent method.
- Mixer: 8 renamable stereo input channels with VU meter, volume fader, mute/solo - Master bus: compressor (threshold, ratio, attack, release, makeup) + limiter (ceiling), LUFS metering - Decks/carts keep their own JACK outputs, completely separate from mixer - MIDI learn: configurable bindings saved to ~/.gti_radiostudio/midi_map.json - mixer_widget.py: QDial-based DSP controls, scrollable channel strips
nickmin