[Mac撚] 用家/買機集中討論(72) BTO無人權

https://support.apple.com/en-us/HT212856
Use high-impedance headphones with new MacBook Pro models
Connect high-impedance headphones directly to MacBook Pro (14-inch, 2021) or MacBook Pro (16-inch, 2021).

The 3.5 mm headphone jack on the MacBook Pro (14-inch, 2021) or MacBook Pro (16-inch, 2021) features DC load detection and adaptive voltage output. Your Mac can detect the impedance of the connected device and will adapt its output for low- and high-impedance headphones, as well as for line-level audio devices.
When you connect headphones with an impedance of less than 150 ohms, the headphone jack provides up to 1.25 volts RMS. For headphones with an impedance of 150 to 1k ohms, the headphone jack delivers 3 volts RMS. This may remove the need for an external headphone amplifier.
With impedance detection, adaptive voltage output, and a built-in digital-to-analog converter that supports sample rates of up to 96 kHz, you can enjoy high-fidelity, full-resolution audio directly from the headphone jack on your MacBook Pro.

Apple docs確認headphone jack高ohm處理
上post我地估佢有circuitry去detect估中，測到高於150 ohm會自動跳去3v 均方壓出
咁我插左隻DT1990PRO (250ohm)聽野都幾夠力，條response curve好似都幾平 (啱monitoring用途)
另外無論3.5mm定speaker都cap響96kHz / 32bit FP (之前有人吹192kHz)
等teardown確認佢用緊咩DAC chip同埋amp係點搞
我覺得唔係玩家純粹做野可以直插，唔洗好似以前咁最少要插隻AudioQuest Dragonfly咁阻掟