MPC Software SP1200 plugin…

Is the plugin supposed to add that white noise ? And then it leaves this ugly trail when I press stop. I’ve never used an SP1200 so idk.

It does add hiss and that tail you hear is caused by the reduced bit rate. It's not very accurate though, but use it if you like the results. Check out wavetracing SP950 for a close replication. One of the key aspects of the SP sound was sampling a 33rpm record played back at 45rpm and tuning down 5 semitones, the wavetracing plugin replicates the resulting artefacts pretty well.