SID vs. SIDizer (real-world comparison): Here is a comparison between the output signal of a real SID chip and SIDizer software regarding the fact that both have been configured with the same values for all parameters. For more information click on the pictures:

8580 LP Filter vs. Modeled	8580 LP Filter vs. Modeled	8580 LP Filter vs. Modeled	8580 LP Filter vs. Modeled	OSC '&' Function vs. Modeled
OSC '&' Function vs. Modeled	OSC '&' Function vs. Modeled	6581 D/A Dist vs. Modeled	6581 LP Filter vs. Modeled	6581 Filter Dist vs. Modeled
	6581 HP Filter vs. Modeled	Audio demo (for comparison) : MOS-6581 Filter Sweep LP SIDIzer-6581 Filter Sweep LP MOS-6581 Filter Sweep BP SIDizer-6581 Filter Sweep BP MOS-6581 Melody LP SIDizer-6581 Melody LP	6581 HP+BP Filter vs. Modeled