Tag Archives: Volumio

A Music Server on Your Raspberry Pi

If you are looking to create a music server on your Raspberry Pi (RBPi), Volumio may be a suitable choice. Although several websites give perfect instructions for setting up the RBPi as a media center for watching films and video series, very few provide solutions for audiophiles who would prefer to have a server dedicated to music.

Volumio is available as a Raspbian distribution. Using the application, one can manage the entire music library on a single device attached to the RBPi. Being very easy to use, Volumio supports all types of audio files—Vorbis, AAC, FLAC, mp3, and more. It even works with several DAC expansion cards. The team behind Volumio maintains it providing updates at least once a month, and this shows their seriousness in supporting this wonderful product.

The best way to get Volumio is to download it from their website. It is available as a Raspbian image, and it is necessary to download the image and decompress it. You will need a micro SD card to flash the uncompressed image—use one with a 16 GB capacity. Flashing requires a PC running Linux, Windows, or MAC. There is no need for an Ethernet cable, as Volumio works with a Wi-Fi connection.

It is advisable to use an RBPi3 with Volumio. On the first run, Volumio proceeds to install the application, which can take up quite a few minutes. In the selection presented, choose Wi-Fi and Volumio will try to connect with a network. If it does not find any network, or the network is inaccessible, Volumio will proceed to create its own hotspot. You can access this hotspot from your PC with the name Volumio and password volumio2. Typing the IP of your RBPi3 or the address volumio.local/ will take you to its web interface.

Once you are able to connect to Volumio on your PC, visit the Network tab, and move to the Wi-Fi Network section, where you can enter the code of security. Now you are fully equipped to run Volumio on your RBPi3, and add all your songs.

This is again a very simple process, and the recommendation is to have an external hard drive for this. Simply store all your songs on the external hard drive and let the RBPi3 use it. Navigate to Browse, then to Music Library, and select USB, which will allow you to see the hard drive. Alternatively, access the contents of the hard drive directly from the Album or Artist sections. Another possibility is to use a Network Attached System (NAS). For this, you must access the section My Music.

Still another possibility is to play the titles of Spotify, and you can do this by adding a plugin. This requires you to navigate to the Plugins section, and installing it from there. Once the installation finishes, activate Spotify on the RBPi.

Volumio is compatible to DLNA and AirPlay. Therefore, it is possible to broadcast audio streams from an iPhone. As Volumio offers a digital output, adding a DAC expansion card to the Raspberry Pi brings further gain in quality and listening pleasure.

Volumio for the Raspberry Pi

When you search for a networked stand-alone audio player with a touch screen, most likely chances are you will only find big consumer grade amplifiers. Those with network support may not have a touch screen or else may be very expensive. Most disappointing will be those having an issue with space and mobility. The best way out of this dilemma is to build one with the famous single board computer, the Raspberry Pi (RBPi).

You must start with an application that works on the RBPi. You can already find good quality DACs on the market. The makers of the application Volumio have used PCM1794A, the DAC from Texas Instruments with good results. As this is a 24-bit device, it can handle sample rates up to 200 KHz, and offers an 8x oversampling filter built-in.

The PCM1794A requires two voltages for proper functioning. It needs the 3.3 V for its digital part and the 5 V for its analog part. Although it seems possible to use the two voltages available on the GPIO expansion connector, the noise present on these voltages precludes their use for the DAC. Another possibility would be use the power supply for the DAC to power the RBPi. However, that is also not advisable, as this would mean degrading the power supply of the DAC. Therefore, the two devices need two distinctly different DC adapters.

For the I/V converter, another voltage is necessary and this has to be a negative voltage. The designers derived the negative voltage using the LM27761 IC, a special switched capacitor low-noise regulated voltage inverter. The IC is extremely small, only 2 x 2 mm, and operates at 2 MHz, introducing very little noise into the circuit.

Both the 5 V and 3.3 V required by the DAC are generated by ultra-low-noise positive linear regulators of the typeTPA7A4700 and TPS7A4901. Voltage dividers made by two resistors fix the output voltage, one pair for the 5 V and the other for the 3.3 V. A Schottky diode protects the input to the power supply against reverse polarity—it drops only 0.3 V from the single power supply of 7-8 V.

The 3.5-inch display goes above the Audio DAC. If necessary, use two standard-size stacking headers to place the display higher to clear the components. This will place the 25-way socket of the display above the Audio DAC PCB.

Performance

Plotting the amplitude of the output as a function of frequency shows the cut-off frequency at about 63.5 KHz. The total harmonic distortion plus noise was measured as a function of frequency with sampling rates of 48, 96, and 192 KHz shows it to be far lower than the acceptable limits—at 0.0007%. Although the RBPi generates several spurious frequencies that are just visible, the level for the fundamental frequencies is very low at -120 dB (1 µV). Those for the second and third harmonics are barely visible.

Various FFT analysis of a 16-bit, 1 KHz full-scale sine wave at different sampling rates shows the harmonic distortion to be far below the acceptable levels— at 0.002%. All these measurements show this tiny board to offer a great audio experience.

Volumio: Control Your Hi-Fi through a Raspberry Pi

Traditionally, amplifiers connect to loudspeakers through wires. The wires carry the electric currents that make the loudspeakers work to produce sound. So far, wires were also necessary to feed amplifiers from different sources such as CD players, TV sets and others. By placing amplifiers within the speaker enclosure, part of the ugly wiring was taken care, but the wires from the source persisted until wireless methods were discovered.

Introduction of the Walkman and other portable players changed the music scenario forever, bringing it out of the living room and allowing people to carry their music with them. However, there was a limit to the number of songs one could carry on their person. The advent of the smartphones and the Internet opened another door. People could stream music over the net, leaving their collection at home. This was the age of iTunes, Spotify and Beats Music, facilitating listening to music wherever you may be.

Most often, these new methods prove expensive for those on a budget, and they are forced to bypass the newer ways of consuming music. An RBPi (Raspberry Pi) is a great help in these cases, simply because the single board computer is affordable, flexible and of a convenient size. Its flexibility makes it a perfect fit for use as a home audio solution and you can control your music wirelessly without having to invest in expensive high-fidelity stuff.

An RBPi gives you many modes of selecting songs to play and the manner in which they are played. For this, the RBPi uses a specially tailored Operating System by the name of Volumio. The major attraction is the nice and simple cross-platform web interface through which you can control music.

The RBPi sits as a controller just in front of the amplifier. It can pick up songs from a USB stick plugged into one of the USB sockets, select it from your local home NAS or take your picking from Web Radio. For the last part, you will need a Wi-Fi dongle to connect the RBPi to the Internet.

Volumio is easy to set up, as not much of advanced functions or graphics are to be handled. Simply download the Volumio disk image, transfer it to your microSD card and use it to boot up the RBPi. You will not require a keyboard, mouse or monitor to set up the software, as the entire configuration is possible through the web interface of Volumio.

Use your computer to connect to Volumio. You can find it by connecting your computer to the same network where you have your RBPi plugged in. You may also use Volumio over a wireless network, for which, you will have to first connect to the RBPi via Ethernet to configure its settings for use with a Wi-Fi dongle. This also allows you to control the software with the browser on your smartphone – simply type in the URL ‘http://volumio.local’ in your browser.

Using the RBPi makes it simple to select songs and set up other parameters for playing them on your home Hi-Fi system. As an advanced arrangement, this is affordable and one can easily modify it to suit specific needs.