- Connecting audio
- Audio PC
- Raspberry & Co
- All in Ones
- Bluetooth
- Chromecast
- Streaming audio player
- Music server
- USB Audio
- Real-time audio over IP
- FireWire DAC
- Multi-channel DAC
- NAS
- Remote control
- Vinyl rippers
- Acoustic materials
- Active crossover
- Active speakers
- Single driver speakers
- Invisible speakers
- Sound card
- Digital room correction
- Headphone
- Portable media players
USB-C
More and more manufacturers of mobile phones drop the 3.5 headphone jack.
Another trend is replacing the micro USB connector with a USB-C connector.
Today you can get dongles with USB-C in and 3.5 analog out.
This means there is a DAC build-in.
A perfect solution to connect wired headphones to your mobile that lacks the analog jack.
However, there is also a USB-C Audio Adapter Accessory Mode.
In this mode the device sends analog audio over the USB!
All you need is a passive adapter.
Obvious, USB-C is the most analog sounding digital bus!
To the best of my knowledge, there is nothing you can do as a user to invoke Audio Adapter Accessory Mode or avoid it. This explains why a passive USB-C - headphone adapter works on some mobiles but not on others. The same applies to USB DAC's.
A bit more about USB and this Audio Adapter Accessory Mode can be found here.
Allo audio Pilot $129.00
ESS Sabre DAC (9281CPRO with MQA support)
SNR: 120db
THD+N @ 0.0006%
< 2 ohm output impedance
PCM sampling frequency up to 384kHz
DSD sampling frequency up to 5.6MHz
Earmen Donald DAC $99
PCM 384kHz/32bit,
DXD, MQA Rendering
DAC: 32 bit Cirrus Logic CS 43198
USB: XMos 2XX
Input: USB-C - DATA/Power Supply
USB-C - External Power Supply
Output: RCA
Dimensions: L * H * W (mm) 114 x 80 x59
Meaurements on 
Google USB-C to 3.5 mm headphone adapter US$12
Is this a passive or a active adaptor?
CableDo did a teardown.
Indeed, there is a DAC inside.
Microsoft Surface USB-C to 3.5 mm adapter $11.99
Looks like a passive but thanks to CableDo we know there is a DAC inside.
Musiland MU1 US $38.50
Supports 16 or 24Bit, 44.1kHz, 48kHz, 88.2kHz, 96kHz, 176.4kHz, 192kHz full sample rate audio format playback.
Headphone output power up to 2x60mw/32 ohms, can drive up to 120 ohms headphones, output up to 300mA transient current.
Intelligent suitable for output impedance, support line output whose impedance above 600ohms; output level IV RMS
Zorloo Ztella
ESS Sabre DAC technology
SNR @ 120dB
THD+N @ 0.0006%
< 2 ohm output impedance
PCM sampling frequency up to 384kHz
DSD sampling frequency up to 5.6MHz
References
- 3.5mm audio vs USB Type-C: the good, bad and the future - Robert Triggs
- USB-IF Publishes Audio over USB Type-C Specifications - Anton Shilov 2016
- Headphone dongles - ASR
- Apple vs Google USB-C Headphone Adapters -