steveww

Not a very friendly form this. Eject!

There are a number of ways to get to a final figure: 68 = 60 + 8 68 = 34 * 2 68 = 17 * 4 It does not matter how you get to that number 68 is 68 no matter what. If the same data is sent to the DAC it does not matter one jot how those figures were derived. All lossless formats sound the same because the data is the same. Sure the loss formats such as MP3 sound different, indeed different implementations of MP3 encoding sound different. However if you believe you can hear a difference between lossless formats then faith is a wonderful thing and there is a whole load of other organisations that rely on this. Keep the faith if it is a comfort to you but that does not alter reality. Creation vs Evolution anyone?

I am running Ubuntu Server 10.04 LTS which ships with 0.15.4 which predates support for S24_3LE. This came in with 0.16. As all my music is 16:44100 CD rips I am trying to decide if it is worth updating?

I notice that the latest version of MPD supports direct S24_3LE format. This is what the V-Link II uses. Given that all my music is CD rips 16 bit 44100Hz is there any advantage to updating MPD? There will still be the need to resample from 16bit to 24bit. Can any Linux, MPD, ALSA guru explain what goes on under the covers?

So if the only thing that changes is the file format how is the route to the speakers different?

Get a MD5 checksum program (if you are unsure what MD5 is Google is your friend here) and try the following: Start with a wav file and compute its MD5 Compress that wav file with FLAC Decompress that FLAC back to wav Compute the MD5 of the new wav file Compare the two MD5 checksums. You will find that the checksums are identical which means there is no difference what so ever between the two versions of the wav file. There will be no difference in sound quality. If you still think there is a difference try a blind A-B test and see how you score.

New V-Link II has arrived and been plugged in to my Linux MPD. Worked first time :-) The V-Link II only supports S24_3LE (24 bit) data format so you have to use plughw:1,0 for the device as ALSA needs to convert my CD rips (16 bit) to 24 bit. I spent some time comparing the V-Link II to my existing Teralink X both connected via Toslink to Benchmark HDR. The difference is very slight but could be spotted in a blind A-B test. The V-Link is a tad smoother, the music is more liquid, slightly less grain or glare. The difference though is very slight it is not a night and day change. I am happy with this new device and it will be staying in the current configuration.

I use a silent Linux PC running MPD as my source. Currently I have a VA Labs TerraLink doing USB -> SPDIF duties. I hear all the fuss about async USB on the forums and I would like to give it a try so I am thinking about getting the MF V-Link II. Of course the MF website does not mention Linux so has anyone out there tried it, does it work and what hacks (if any) did you need to do?

Just run MPoD on your iPad. It runs just fine as the iPad has a compatibility mode for iPhone apps. It would be nice if the author of MPoD did an iPad version but....

The new Naim DAC puts the data from SPDIF in to a FiFO (First In First Out) RAM buffer and then clocks the data out of that via its own master clock to the DAC process. They have a very interesting white paper on how it all works on their web site. http://www.naim-audio.com/products/dac.html

Whilst reconfiguring my home network and server utilisation I can across a great little device called Linksys NSLU2 (aka slug). Alas it is no longer available new but eBay has loads of them. Why would you want one I hear you ask? In standard form it runs a mini Linux and acts as a NAS via Windows share (SMB). However it has been well and truly hacked and can easily run a pretty full Linux system. I have put Ubuntu server 9.04 on mine and it runs as a NFS server. Out of idle curiosity I checked and yes MPD has been ported to it and yes it does recognise and support my TerraLink-X USB -> SPDIF dongle. Decompressing a FLAC file and piping it to a USB port is not going to tax its limited CPU power. It is a tiny box that does not have a fan and could be run off a pocket USB hard disk or a couple of thumb drives. I am now seriously considering using one of these instead of my recent Acer Revo and making the Revo my new mail server. See http://en.wikipedia.org/wiki/NSLU2

I have just been researching all of this. Here is what I found out: The TerraLink-X USB -> SPDIF dongle is £38 and works with Linux just by plugging it in. SPDIF gives you a wider choice of DACs to choose from. USB based DACs will work if they are based around the CMI108 or Burr Brown 270x series of chips. www.maplin.co.uk do an entry level USB -> SPDIF dongle product number A56AK for £20. I tried this an it works a treat. As long as you have installed ALSA for your distro then aplay -L lists all the available playback devices. You can then use one of those names in the device clause of the mpd.conf file. Simples :-)

I have just build a Ubuntu music server (see other post). Yes it does all work :-) Minimal Ubuntu 9.10 sshd alsa mpd mpc The built in sound card will make noise but not produce Hi-Fi quality sound. An external USB DAC is one option but be careful as some of these require special drivers that are not available for Linux. Alternatively a USB -> SPDIF dongle will work. I got one from http://stores.ebay.co.uk/Vintage-Audio-Lab and it works just fine. I have run the on board and external optical SPDIF to my external DAC and can not tell the difference between them. General opinion appears to be that optical is better as it provides greater electrical isolation and reduces noise. For bit perfect digital out my mpd.conf looks like: audio_output { type "alsa" name "Onboard SPDIF" device "iec958:CARD=NVidia,DEV=0" } If you have an iPod Touch or iPhone look in the app store for the free app MPoD it is a remote control for MPD.

Now that I have had the new system running for a few days I can say that all is going very well apart from the wireless performance. The RF sensitivity of the Wi--Fi is very poor. At the same location my laptop reports 80% signal quality but the Revo only manages 35%. As a result of it seeing a low signal quality it tends to drop the connection quite a bit. A quick search on the internet reveals that this is a common problem. Looking inside the case the built in aerials are not that great and there is not any external connector for a better aerial. I have ordered a Wi-Fi repeater to boost the signal strength in to my listening room. When the Revo has a good signal the Wi-Fi works just fine.

My new Acer Revo 3610 arrived yesterday. I put Ubuntu Server 9.10 on it with MPD. The build in optical SPDIF port worked right away and gives bit perfect out put in to my old DAC. I am using MPoD on my iPhone as a remote control. All working very well and easy to set up :-) The Revo is essentially silent in operation, you can only hear the fan with your ear right against the box. The unit itself is tiny and fits neatly in alongside the amplifiers etc. Just got to rip all those CD to FLAC now :-(