Different generations of chips, or various cheap clone chips, sure.
Within one generation, evidence of significant differences seems weaker. Sure, manufacturing had loose tolerances, you could end up with a "faulty" chip, but most SIDs sounded the same. You could also end up with a 6510 that crashed after 30 minutes.
Within one generation, evidence of significant differences seems weaker. Sure, manufacturing had loose tolerances, you could end up with a "faulty" chip, but most SIDs sounded the same. You could also end up with a 6510 that crashed after 30 minutes.
https://www.youtube.com/watch?v=yadWu7hs4MU
https://www.youtube.com/watch?v=n73-ipWMCCY