Both are dongles, $9 against $12. This page puts them side by side on the only three things a maker can be held to — power, output impedance and noise — and then asks the question that actually matters: which headphones do they treat differently?
The Generic CX31993 dongles reaches 100 dB on 553 of the 567 models here, the Apple USB-C dongle (US) on 547.
| Specification | Apple USB-C dongle (US) | Generic CX31993 dongles |
|---|---|---|
| Power into 32Ω | 30 mW | 60 mW |
| Power into 150Ω | 8.0 mW | 18 mW |
| Power into 300Ω | 4.0 mW | 9.0 mW |
| Power into 600Ω | 2.0 mW | 5.0 mW |
| Output impedance | 1 Ω unverified | 1.5 Ω unverified |
| Output noise | 6 µV unverified | 8 µV unverified |
| Price | $9 | $12 |
| Headphones it reaches 100 dB on out of 567 | 547 | 553 |
A figure marked not published is missing from the maker’s own material, which is not the same as being good or bad. Where one of these two publishes a number and the other does not, the comparison on that axis cannot be made at all — and saying so is more useful than guessing.
6 headphones reach 100 dB on the Generic CX31993 dongles but not on the Apple USB-C dongle (US) — Beyerdynamic DT 880 Edition (600Ω), Beyerdynamic DT 990 Edition (600Ω), HiFiMAN Susvara Unveiled, 3 more.
547 of the 567 models here reach 100 dB on both. That is a power count and nothing more; whether either source suits a given headphone also depends on the two lines above.
Each has a page of its own with a full headphone list and the provenance of every figure — worth opening here, because Apple USB-C dongle (US) and Generic CX31993 dongles have published no electrical specification at all and everything above comes from independent measurement: Apple USB-C dongle (US) and Generic CX31993 dongles. Or put either against your own headphones in the source comparison tool.