Post by MartinT on Aug 1, 2014 14:06:56 GMT
File-Based Audio Streamer Project
See also complete build article here!
This thread will form an ongoing project to build a high quality music streamer from easily available components. The objective is to keep the price low while achieving the highest possible audio quality. We encourage members to consider buying the parts and follow us along an interesting and fun journey from a very basic streamer to something that can form an integral part of your hi-fi system. The total initial cost slightly depends on whether you have cable or wi-fi ethernet, but around £50 ($84) will get you started.
The ethos of the Logitech Touch is what we're aiming at, but at about one-third of its price and still more flexible. The Touch is no longer available, so a project based around it would not have been very appropriate for most members.
The benefit of a streamer, as opposed to an all-in-one music server, is that your music collection can be tucked away somewhere else in the house, taking its audio and electrical noise and heat away from your hi-fi system. The streamer is the only component close to the system and can be unobtrusive, low power, low noise and low thermal output in nature.
Introduction to the Raspberry Pi
The Raspberry Pi is a low cost single board computer, about the size of a credit card, with a SOC (System on Chip) 700MHz ARM processor. It's designed to run Linux although other operating systems are available for it. An SD card is used for the OS and local storage. You can power up one of these, plug an HDMI monitor or TV in, connect up keyboard and mouse, connect it to your router and be browsing the internet within half an hour. It's a truly remarkable bit of kit.
The version we are going to be using here is the Raspberry Pi B+, the latest model, which includes better optimised USB ports (good for USB DACs) and lower power consumption (good for when we start to experiment with battery power). It is relatively new, so we will have to wait for some nice add-on boards to be released, such as optical/co-ax digital outputs (e.g Hi-Fi Berry Digi and Squirrel Sound Card) and fully fledged onboard DACs (e.g. HiFiBerry DAC and Element 14/Wolfson DAC). They are coming soon.
Selecting the Best Software
There are quite a few software audio streamer solutions for the RPi out there, including Volumio and MPD. For ease of use, great reputation and nice universal user interface, we will be using Volumio. It doesn't require a display, being completely configurable via its web browser interface. It also accesses your music collection via simple SMB shares, so it's very easy to connect to a PC, Mac or NAS file store without any server software. Finally, it's open source and costs nothing.
Controlling it All
One annoyance with the Logitech Touch is the plethora of different apps to control it, none of which have a complete handle on necessary functions and all of which appear to be buggy to a greater or lesser degree. There is also dependence on LMS (Logitech Media Server) being installed on the PC containing your music, a concept best done away with.
With Volumio, all you need is a tablet or phone with a browser, any platform will do. That's it - no app required!
Raspberry Pi Model B+
8GB fast MicroSD card
5V mains power supply or 5V phone extender battery
PC, Mac or NAS store with your music file collection
Ethernet cable or wi-fi network
Laptop, tablet or phone with browser
Everything else will be optional:
I2S board with S/PDIF outputs for external DAC (I'm using the HiFiBerry Digi+ board)
Onboard DAC (there are several models including the HiFiBerry DAC+)
The great thing about this project is that it can be taken in easy steps, starting with just simple streaming to a set of earphones and testing everything along the way.
Members are encouraged to contribute their questions and findings to this thread, building up a comprehensive knowledgebase on the subject.