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Post by canetoad on Aug 1, 2014 23:03:30 GMT
Looking forward to following this. Comparisons with the Touch would be very interesting. Does anybody know what sort of processing power the Touch has?
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Post by MartinT on Aug 1, 2014 23:17:46 GMT
I can't find information about the processor in the Touch but it's a pretty low power one running a Linux kernel. I have EDO and TT3 tools installed in an attempt to shut down as many services as possible and improve sound quality. It performs to a very good level in this mode, so we shall see how the RPi compares.
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Post by chukka on Aug 1, 2014 23:25:31 GMT
hi Martin, at what rate will it be streaming the bits to the DAC ?
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Post by MartinT on Aug 2, 2014 6:20:09 GMT
If we use the forthcoming HiFiBerry Digi module, it claims to handle all rates up to 24/192. It depends on your files, of course.
The RPi/Volumio can also upsample files.
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Post by Tim on Aug 2, 2014 9:51:43 GMT
Nice one Martin, based on what I have heard with a previous Pi (not the new B+) it should certainly satisfy Touch owners looking for an alternative. Start adding batteries or good power supplies and you will have a very capable and affordable device. I like the case you have selected too.
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Post by Dave on Aug 2, 2014 13:05:10 GMT
They do a spruce version too which I like very much
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Post by MartinT on Aug 2, 2014 13:23:46 GMT
Glossary of Terms
ARM - a family of RISC (Reduced Instruction Set Computing) processors designed by Cambridge, UK, based ARM Holdings. Used extensively in mobile phones and small devices. Class (in SD cards) - speed rating of the memory, affecting how quickly it can be written to / read from. Class 6 is 6MB/s, Class 10 is 10MB/s etc. CPU - Central Processing Unit - the computing chip which performs all calculations. When combined with memory, forms the brain of the device. DAC - Digital to Analogue Converter - a device which converts audio data represented by numbers into an analogue signal that we can hear. DHCP - Dynamic Host Configuration Protocol - the process whereby a unique IP address is assigned to a device, within a network, to allow it to be communicated with. Frequently used where an internet provider supplies a single IP address but many devices exist within the user's network, for instance small business and home networks. Ethernet - a method of networking devices together using packets of information with source and destination addresses. The connection method can be via cable or wi-fi (wireless). HDD - Hard Disk Drive - a type of non-volatile computer storage consisting of rotating magnetic platters read and written to by moving heads. HDMI - High Definition Multimedia Interface - a method of connecting display devices such as TVs and monitors to devices or computers generating digital video and audio output. I2S - a serial interface used for connecting digital audio devices together, featuring separate clock and data signals for better sound quality. IP - Internet Protocol - a method of addressing devices on a network or the internet such that no two devices on the same network have the same address. Linux - a Unix-like open source operating system for computers, created by Linus Torvalds MicroSD - the micro size format of an SD card. MPD - Music Player Daemon - an open source music player server. This is the underlying software powering Volumio. NAS - Network Attached Storage - computer storage attached directly to a network for access by multiple devices. OS - Operating System - the management control system that allows you to interact with your computer. Typical OS for small computers include Microsoft Windows, Apple MacOS, Linux and Chrome. RAM - Random Access Memory - memory that can be written to and read from in any order. Router - a device which provides the interface between an internet feed and an internal network. A typical router takes a broadband or cable provision and provides ethernet sockets and wi-fi to the household, such as a BT Home Hub or a Virgin Media Hub. Scrobbling - scrobbling means that when you listen to a song, its name is sent to Last.fm and added to your music profile, forming a statistical history of your listening. SD - Secure Digital - non-volatile memory storage card. Comes in three sizes: original, mini and micro. SOC - System On a Chip - a single integrated circuit containing all the essential ingredients of a computer - CPU, RAM and display graphics. Typical applications include mobile phones and, of course, the Raspberry Pi. S/PDIF - Sony / Philips Digital Interface Format - a method of sending digital audio information in a stream along a co-axial or optical (TOSlink) cable. SSD - Solid State Disk - a type of HDD but with no moving parts, consisting only of non-volatile RAM. SSID - Service Set Identification - used especially in wi-fi networks to identify it by name USB - Universal Serial Bus - an industry standard for digitally connecting computers with devices, allowing communications between the two and supplying power, if necessary.
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Post by chukka on Aug 2, 2014 15:55:16 GMT
If we use the forthcoming HiFiBerry Digi module, it claims to handle all rates up to 24/192. It depends on your files, of course. The RPi/Volumio can also upsample files. Very interesting. Are you going to use/test the USB output and maybe compare it to the HiFiBerry Digi module output ? Ideally, I would use the USB output if recommended. My DAC has a very good USB input which I currently don't use. I read somewhere, that the Raspberry can also be used as a Spotify server which is awesome.
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Post by MartinT on Aug 2, 2014 16:21:31 GMT
I am using the USB input of my Caiman II DAC for testing while I await the release of the HiFiBerry Digi board for the B+. I will certainly make the comparisons. I expect the S/PDIF output to beat the USB for performance, but we will see.
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Post by MartinT on Aug 2, 2014 16:53:55 GMT
Spotify is something I hope will come to Volumio. I intend contacting the author about it.
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Post by chukka on Aug 2, 2014 22:28:10 GMT
yep, that would free up the iphones around the house for incoming calls if the B+ could do the streaming !!
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Post by MartinT on Aug 3, 2014 21:10:33 GMT
5. Setting up Wi-Fi
If you need to use Wi-Fi, make sure you have a Wi-Fi dongle connected to a USB port of the RPi. In Volumio, go to Menu | Network. Scroll down to Wi-Fi Setup. Fill in the Wi-Fi SSID name, type of security and password for your security encryption. This information is frequently found under the router or in a pull-out tab, unless you have changed the details yourself. Click SAVE CHANGES.
Unplug the Ethernet cable, power the RPi off and back on again and see if you can now browse to it over wi-fi as in Section 3 above.
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Post by MartinT on Aug 4, 2014 8:18:25 GMT
6. Testing
You should at this point be ready for some music testing. Plug a set of earphones or headphones into the RPi audio jack. The audio jack does not provide a very high quality output, we are using it only for testing purposes before connecting the RPi to a hi-fi system. Plug a local USB drive containing music files into the RPi if you intend using it with local storage. Otherwise, ensure that you have some music files in your share folder.
Perform a Library Update: go to Menu | Library and click UPDATE MPD DATABASE. You need to do this whenever you add music or a local drive to the system, although there is a setting to automatically detect changes.
Now go to Browse and you will see one or more selections as below. NAS selects your network share, USB selects locally connected storage and WEBRADIO allows you to stream Internet radio.
Showing the listing from a USB drive (see the tell-tale info at the folder icon bottom-left)...
Showing a part of my NAS Library when clicking Library. The apparent screen corruption is text wrap because I reduced the window size for copy/pasting...
Volumio works on a playlist principle, by adding songs to a playlist and then playing it. You can also play songs immediately. Try this now and, if all is working well, you should hear music through your earphones. If you need to adjust the volume, click Playback and adjust the volume control. This is the screen you will normally leave the RPi displaying when playing music.
You have now effectively commissioned your RPi streamer. All further articles are going to cover connecting it to your hi-fi system and getting the best sound quality from it.
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Post by MartinT on Aug 4, 2014 16:24:37 GMT
A couple of screenshots from my phone showing how nice the Volumio control interface looks on a small screen.
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Post by MartinT on Aug 5, 2014 18:16:17 GMT
There will be a short break until I can order the RPi B+ version of the HiFiBerry Digi board, which is coming out very soon now. This will give S/PDIF outputs so that I can drive my Caiman-II DAC optimally at all resolutions.
For now, a short appraisal of what I can hear: - via the audio jack: the less said about this, the better. Fairly horrible with lots of background switching noise. Better in the B+ than the original RPi, but not usable in Hi-Fi applications. - via USB into Caiman-II: passable to good. I can hear great sound struggling to get out but it's dynamically flat and lacking in detail. This is probably a combination of the RPi working hard to deliver the digital stream via USB (always processor intensive) and the USB input of the Caiman-II being the poorest sounding of its four inputs.
The Digi plug-in board should allow the RPi to soar as it connects via the I2S interface, which is very efficient and not processor intensive.
There is another option for those without a DAC: HiFiBerry make a full plug-in DAC for the RPi which promises good things. This again should be released shortly in B+ format.
We also have battery power to come, so stand by for more soon.
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Post by MartinT on Aug 5, 2014 20:19:28 GMT
I should explain that USB comment for the uninitiated: the USB serial communications system is a marvellous general purpose interface for computers and devices. However, it has little intelligence and requires substantial CPU power to generate the data stream. This stresses both the CPU and power supply to the detriment of sound quality by increasing jitter in the datastream and putting more noise into the power rails.
I am not a lover of USB connected DACs for the same reason. They don't sound right to my ears.
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Post by John on Aug 5, 2014 20:55:03 GMT
There a few good USB based DACs out their Martin you be surprised what they can be capable off. The few I heard are certainly the equal of the Caiman mk 2 and they only using a netbook as a dedicated built PC optimized for Audio would probably be more than a match
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Post by chukka on Aug 6, 2014 21:00:38 GMT
I should explain that USB comment for the uninitiated: the USB serial communications system is a marvellous general purpose interface for computers and devices. However, it has little intelligence and requires substantial CPU power to generate the data stream. This stresses both the CPU and power supply to the detriment of sound quality by increasing jitter in the datastream and putting more noise into the power rails. I am not a lover of USB connected DACs for the same reason. They don't sound right to my ears. Hi Martin, your article inspired me to get a Raspberry as well. Just before pressing the "Buy" button I changed my mind and got a CuBox-i2 which was a little more expensive but has a built in optical out, more RAM and a faster processor. It also comes bundled in a plastic housing which is about 5cm x 5cm x 5 cm. Volumio does not yet have a fully compatible version for the i2 so I used a hacked version just to get it running in limited mode for the time being. What does work however is the USB to DAC connection. And I was quite pleasantly surprises by the sound that was coming out of the speakers. I'm no good at describing that sort of thing but it sounded more dynamic and full than the Airport express optical out > DAC configuration I have been using lately. The little cuBox served deliberately up-sampled streams without any hiccups at all. In fact I couldn't believe that it would be able to do that in real time. Quit surprising for such a diminutive box. The one thing that I really find disappointing is the user interface. It is definitely a giant step back from what I have gotten used to (spotify, itunes, etc.). When the full version of Volumio for the cuBox comes out I will be able to give the optical out port a try. Ideally, I would like to use the cuBox as a bridge to the DAC (Network > Airplay > cuBox > USB > DAC) as the Airplay stream on the cuBox doesn't seem to be limited to 44.1khz like Airport Express. Cubox home page: www.solid-run.com/products/cubox-i-mini-computer/
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Post by MartinT on Aug 7, 2014 5:57:00 GMT
Nice one, chukka. I did look at the Cubox boards as well as the Udoo, Beaglebone and Cubitruck boards. The reason I went with the RPi is that it has the largest installed base, is very popular in the educational market and is well supported with technical knowledge and plug-in boards and is inexpensive. There is good software support over and above Volumio. For this project, it seemed the most appropriate. May I suggest that you start a blog and let us know what you've done with it, how you hacked Volumio, how upsampling sounds etc? We will soon have a 'guinea-pig' member build a RPi project and document his progress in a blog, too.
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Post by MartinT on Aug 8, 2014 17:52:19 GMT
Temporary Project Halt!
When I received my RPi B+, it had a fault in it, so I returned it for replacement. Meanwhile, I've calmly continued with all the above project steps using a work RPi B. Today I received a replacement B+ and it doesn't work with Volumio. I get an eth0 error 'cannot start the Ethernet subsystem' (looking at the boot-up sequence via an HDMI monitor). Looking at the net, it seems others are finding the same problem. There are fixes so I'm just evaluating what needs to be done to fix the Linux kernel by using the latest NOOBS kernel and getting back on track.
In case anyone wants to do it by hand, shown here are the extracted bootcode.bin and kernel.img files from the NOOBS download, copied onto the MicroSD card, required for Volumio running on the B+.
If this terrifies you, skip and see the next post!
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