Raspberry Pi. Yum.

[gjm]

In order to avoid hijacking Mike's Pico thread, I thought I'd copy Richard's and my comments about Pi here instead.

I have heard good and bad about them, from the "why aren't all small low-power PCs supplied with these?" through to "don't touch them!"I'm looking at using a Pi for a music server and the Raspyfi folk all use good quality power supplies. They've done their testing using Audio Diffmaker and have seen improvements by ensuring the power supply to the Pi is good. The output sound wasn't the issue, it was the occasional and admittedly fairly minor issues that dirty mains supply was causing.

Keep us posted, even if only to say 'still working...'

I use a Raspberry Pi as an MPD music server and it is an OK option if it actually works with your DAC. I use a Pi with my B&W MM-1 desktop system which have an adaptive USB input. In my main system I'm using a BeagleBone Black which costs about the same as the Pi, but the USB actually works with asynchronous DACs such as my HRT Music Streamer II+, or USB/SPDI/F converters like my V-Link. There are other low power ARM options such a the Cubox. My BeagleBone and Raspberry Pi use about 2 watts of power from linear PSUs I got from Item Audio. It seems to me that if your audio computer is consuming 120 watts you must be doing something wrong.

There's an extensive list on the Raspyfi site describing many DACs and converters that work. The impression I got was that with later revisions of firm and software, most now do... Although I've not tried.

I'll be looking at a Pi Model B, with 512Mb RAM and 2 USB ports, and trying the Ramplay feature. This downloads an entire lossless album (provided it is no more than ~400Mb) into memory and plays back from there - no drive interaction required.

More as I think of it - right now it is breakfast time!

 

[rdale]

There's an extensive list on the Raspyfi site describing many DACs and converters that work. The impression I got was that with later revisions of firm and software, most now do... Although I've not tried.

Which DAC do you intend to use? I think the RasPyFi site tends to be over optimistic about the current state of USB audio with the Raspberry Pi. I did a write up a couple of weeks ago about my experiences with using a Raspberry Pi to drive my B&W MM-1s, and it works very well with those.

I'm intending to do a similar post describing my experiences with using a BeagleBone Black as an MPD server to drive a Musical Fidelity V-Link in my main system. It sounds really good and I don't think I will be going back to my MacBook with BitPerfect and Decibel.

 

[gjm]

I'm not using a USB DAC; I have a USB -> S/PDIF converter which connects to my Danish Audio Designs DAC.

I'd also been looking at Odroid but that looks to need a little more development capability on the part of the user. BeagleBone isn't something I'd heard of - I'll take a look.

 

[pgarrish]

Definitely don't scrimp on the power supply. Everything on the Pi uses the USB power bus, including the LAN connection - if the power supply isn't up to it you wont even be able to connect to the network, you'll just get strange errors. I found that a Blackberry phone charger was pretty good when I borrowed one.

 

[rdale]

Definitely don't scrimp on the power supply. Everything on the Pi uses the USB power bus, including the LAN connection - if the power supply isn't up to it you wont even be able to connect to the network, you'll just get strange errors. I found that a Blackberry phone charger was pretty good when I borrowed one.

A linear power supply is best, I use PSUs from Item Audio for both my Raspberry Pi and BeagleBone Black MPD servers:

http://www.itemaudio.com/index.php/power-supplies/linear-psus/detail/28-linear-psus/flypage/1080-5v--1a-linear-psu.html?sef=hcfp

It might be the same as this model from Farnell, which is a bit cheaper, I'm not sure:

http://cpc.farnell.com/1/3/5v-1a-linear-psu

 

[rdale]

A linear power supply is best, I use PSUs from Item Audio for both my Raspberry Pi and BeagleBone Black MPD servers:http://www.itemaudio.com/index.php/power-supplies/linear-psus/detail/28-linear-psus/flypage/1080-5v--1a-linear-psu.html?sef=hcfp

It might be the same as this model from Farnell, which is a bit cheaper, I'm not sure:

http://cpc.farnell.com/1/3/5v-1a-linear-psu

Slight correction to this. The Farnell/Item Audio Stontronics Linear PSU doesn't work with the Raspberry Pi mini USB socket and you need an adaptor cable which Item Audio can supply. It is a bit of a lash up though, and it would be nice to find a high quality linear PSU that had an integral mini USB plug. The BeagleBone's 5v power socket works fine with one of the adaptors supplied.

 

[belloire]

i've got a raspberry pi. never used it, and probably never will.

must sell it.........

 

[AmDismal]

I would be tempted to get something that gives out more than the minimum 1A. I had some odd errors when I used a shitty PSU (none of the errors indicated lack of power - quite hard to debug!), so I imagine that the Pi alone needs most of that 1A - when you add a wifi card and other peripherals, 1A may be marginal. Oh and the PSU I used said it was 1A...

Meanwhile, check out MPD before you commit fully to this path. It's OK, but not the most featureful player...

 

[rdale]

I would be tempted to get something that gives out more than the minimum 1A. I had some odd errors when I used a shitty PSU (none of the errors indicated lack of power - quite hard to debug!), so I imagine that the Pi alone needs most of that 1A - when you add a wifi card and other peripherals, 1A may be marginal. Oh and the PSU I used said it was 1A...Meanwhile, check out MPD before you commit fully to this path. It's OK, but not the most featureful player...

I would think the problems were more likely to be caused by the voltage of the PSU dropping under load, rather than it running out of current.

 

[gjm]

I've been reading several forums other than RaspyFi and there does seem a consensus that 1A isn't enough for reliable use under anything but the lightest use. A solid 5V at 2A seems preferable.

As for the USB power connector, why not just connect 5V directly to TP1(+) and TP2(-), bypassing the connector completely? It does bypass the fuse too, but it'd be easy enough to use something inline.

 

[rdale]

I've been reading several forums other than RaspyFi and there does seem a consensus that 1A isn't enough for reliable use under anything but the lightest use. A solid 5V at 2A seems preferable.As for the USB power connector, why not just connect 5V directly to TP1(+) and TP2(-), bypassing the connector completely? It does bypass the fuse too, but it'd be easy enough to use something inline.

I can't connect directly to TP1 and TP2 because my MPD Pi is in a fancy Cool Trays aluminium case. I need to buy a mini USB plug and solder it on myself.

I can't see why RaspyFi think that more that 1A is needed as the Pi itself consumes less than 500 mA and you would need some very current hungry USB devices to draw another 500 mA. Anyway I think it is best to use only one USB device, ideally not powered by the Pi's USB - just the DAC or Speakers or USB/SPDI/F converter you are using and an ethernet cable to use to NFS mount a music collection on your NAS.

 

[gjm]

I agree. The power set up on the Pi means that anything connected really needs to be self-powered in order to avoid the possibility of affecting the Pi output. Unfortunately my USB -> S/PDIF converter doesn't make it easy to power it from anything other than the device it is connected to.

Richard will probably have seen that RaspyFi recommended cutting or disconnecting the +5V line on the USB connection to a NAS or other external data source, but retain the ground line. This can cause problems with some DACs (in particular) where the +5V is used for handshaking, then ignored during data transfer.

 

[rdale]

I agree. The power set up on the Pi means that anything connected really needs to be self-powered in order to avoid the possibility of affecting the Pi output. Unfortunately my USB -> S/PDIF converter doesn't make it easy to power it from anything other than the device it is connected to.

I use an AQVOX PSU to power my Musical Fidelity V-Link and that works fine with my BeagleBone, and it means that all the BeagleBone PSU has to do is to power the BeagleBone. The AQVOX is relatively expensive, and about as much again as the V-Link. Item Audio do a cheaper alternative:

http://www.itemaudio.com/index.php/analog-digital-cables/detail/4-cables/flypage/1081-dual-conduit-usb-kit.html?sef=hcfp

Sorry about sounding like an advert for Item Audio, I've no connection with them and am only plugging their stuff because they seem to have got some interesting things like this dual conduit USB cable/linear psu bundle that I haven't seen anywhere else.

 

[gjm]

I use an AQVOX PSU to power my Musical Fidelity V-Link and that works fine with my BeagleBone, and it means that all the BeagleBone PSU has to do is to power the BeagleBone. The AQVOX is relatively expensive, and about as much again as the V-Link. Item Audio do a cheaper alternative:http://www.itemaudio.com/index.php/analog-digital-cables/detail/4-cables/flypage/1081-dual-conduit-usb-kit.html?sef=hcfp

Sorry about sounding like an advert for Item Audio, I've no connection with them and am only plugging their stuff because they seem to have got some interesting things like this dual conduit USB cable/linear psu bundle that I haven't seen anywhere else.

Item have a lot of good-looking kit on their shelves. Some of it is a bit pricey (imo) and I know there are those on the Wam who don't like Item. Each to their own. I don't like McDonalds, but I'm sure there are Wammers who go there. I'm not judging them!

Nice to see a linear PSU being used (based on what I have read comparing linear and switched), although Nelson Pass will tell you it makes little difference provided the supply is correctly implemented. I don't know.

I must be able to find something similar from HK for about half the price! At that price it's worth a try.

I had a look at BeagleBone. It almost looks expensive compared to Pi! More on a par with ODROID. More looking and research needed.

 

[rdale]

I had a look at BeagleBone. It almost looks expensive compared to Pi! More on a par with ODROID. More looking and research needed.

Are you sure you were looking at BeagleBone Black? On the Farnell UK site the Pi is 28 pounds and the BB is 31 pounds. The BB comes with 2Gb built in flash and so an SD card is optional making them cost pretty much exactly the same.

 

[gjm]

I just checked nz.element14.com - Farnell to all you European people - and the prices are much closer than I expected. I'd seen US$85 quoted for the BBB and assumed it would be much more expensive.

How much Linux/programming knowledge is required for the BBB? Presumably there is a similar support environment in the form of forums and the like as there is with Pi?

 

[gjm]

Just found http://beagleboard.org/Community/Forums but a search on the entire forum for "music server" doesn't yield any results. :-( More effort needed, on my part.

 

[rdale]

I just checked nz.element14.com - Farnell to all you European people - and the prices are much closer than I expected. I'd seen US$85 quoted for the BBB and assumed it would be much more expensive.How much Linux/programming knowledge is required for the BBB? Presumably there is a similar support environment in the form of forums and the like as there is with Pi?

I use the Debian Wheezy distribution which is the same distribution as Raspian on the Pi, and so any articles about setting up MPD software on the Pi are pretty much the same for the BeagleBone. There is a much larger Raspberry Pi community that there is for the BeagleBone though. You need enough Linux/programming knowledge for follow instructions about installing packages, building programs and editing config files. I'll try and write up some instructions today about how I set up my BeagleBone.

 

[gjm]

I use the Debian Wheezy distribution which is the same distribution as Raspian on the Pi, and so any articles about setting up MPD software on the Pi are pretty much the same for the BeagleBone. There is a much larger Raspberry Pi community that there is for the BeagleBone though. You need enough Linux/programming knowledge for follow instructions about installing packages, building programs and editing config files. I'll try and write up some instructions today about how I set up my BeagleBone.

Sounds good... Maybe start a BBB thread?