Thanks for the tip and for helping me understand what might be causing this! I wondered if the original iPods had more power output or something. The headphone

Thanks for the tip and for helping me understand what might be causing this! I wondered if the original iPods had more power output or something. The headphones in question were cheap Koss Porta Pro Classics, and they appear to have a 60 Ohm impedance. That seems somewhat normal, but would that stand out to you? If you've never tried the Porta Pros, they're the best bang/buck I've ever found for headphones.