Rpi Zero with a Generic Low Cost USB audio Card & Zero with USB and a PCM2704 chip from Texas Instruments.
Lowest cost Rpi audio solution I have found is using the Zero with a inexpensive wifi card and a USB music card, total cost $10. I found audio popping with this scenario. But at a slight increase to $11.50 the sound quality is much nicer using a USB with the PCM2704 chip from Texas Instruments. Both options require additional $'s evaluation for microsd card and power supply. My friends at the Raspberry Pi Discussion Forum turned me onto the PCM2704 low cost USB card that in my opinion outputs nice acceptable sound quality (thanks clacktronics for the suggestion).
|MoOde software over wifi from Rpi Zero powered USB hub w/PCM2704 audio.|
|USB is complicated here, but will be simplified. Zero has a camera too.|
|Inexpensive USB audio, PCM2704 on bottom; both work on Zero w/MoOde, hot swapping is OK|
|The USB Hub which was destroyed by trying to attach the USB Audio directly.|
A pi Zero running v3.0 MoOde used 5.16V and 0.19 amps which is 0.98 watts running a USB audio card and a wifi dongle through a USB hub. While starting up this used more power for a very short period of time. 1 watt powered the pi Zero headphones, slightly higher when performing wifi interactive communications. The Rpi3 used 0.26 amps or 1.35 watts for the same functionality.
|Solar powered w/Li-ion battery, Rpi0 with USB Audio, wifi and small speaker.|
This tiny solution would enable an inexpensive car audio system controlled by a cell phone. Or just listen with headphones.
The comparison of these USB audio systems needs to be compared to a Google Chromecast Audio because the Chromecast has great functionality with lots of audio software. Other very low-cost solutions exist that don't have an amplifier including the items in the photo below (counterclockwise from the top: Rpi0, USB audio card, USB audio card with optical SPDIF, Chromecast Audio with analog and optical SPDIF).
The audio evaluations has been broken out into the following audio sections:
- Introduction (Hardware, Software, Energy)
- Rpi Zero w/ Two Different Inexpensive USB Audio Cards (this post)
- Grateful Dead Playing in Parks
And a related post, Uniqueness of the Rpi.