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08-14-2013, 02:45 AM #1
My BeagleBone Black + integrated DAC music server / streamer project page
Based on the introduction of the BeagleBone Black here on ComputerAudiophile I decided to give it a try.
Although the setup instructions were clear I could not mount my CIFS NAS share with the suggested settings so after trying different settings I fount this one to work for me:
//192.168.1.xx/Data/Music /mnt/music cifs username =******,password=********,iocharset=utf8,sec=ntlm 0 0
My NAS is a Netgear ReadyNas Duo V1 with latest firmware.
Reading the topic of Renato building a custom case this simple and elegant I decided to build something similar but take it a level higher in infrastructure.
I will build an aluminium case based on U-shaped profiles (2 stacked on each other) with aluminium top and bottom plates but also using a centre divider creating 2 closed compartments.
In the bottom part I will put the BBB server and in the upper part I will put the Lindemann USB DAC (bare PCB only) and a custom built power supply.
The supply will have 3 seperate outputs (DAC / BBB / USB) with multi-stage filtered RC network and shunt regulator for stable and clean 5Vdc out. External power is through a brick type power supply which delivers 15Vdc.
I will remove the DAC backplate and LINE OUT connector, put some Neutrik NF2 style chassis connectors in the backpanel, remove the mult-colored LED's from the DAC PCB and mount LED's and selector button in the frontpanel extended via a flatcable.
The BBB is shown at the same spot as the DAC PCB but it is actually mounted in the lower part of the cabinet.
I can use an USB cable of only few cm's through the centre plate and solder the signal leads (USB power comes external) direct on the corresponding pins of the XMOS board connector for shortest signal path bypassing the dedicated USB input connector completely.
Although it is designed that way the TI ARM processor can be quite warm to the touch.
The first modifications already are already done: lowering thermal stress for 24/7 operation ;-)
From an ATI graphic card from my old PC I had some adhesive heatsinks which were meant for additional cooling for the overclocked RAM chips.
They fit nicely on the processor and RAM / MMC memory.
This will be an ongoing project page so do not expect regular updates weekly because I still have to collect all the parts before I can build it.
Besided that I also have to tweak the buffer settings in the MPD config files to get the best and fluent playback.
P.S. I know I will probably lose my warranty / manufacturer support on the Lindemann DAC ;-)MPad -> BeagleBone Black + NetGear ReadyNAS -> Lindemann USB DAC 24/192 (XMOS) -> DH Labs Revelation -> NAD C162 -> DH Labs Revelation -> Odyssey Khartago Plus -> DH Labs Q10 -> Boenicke Audio W5
08-14-2013, 06:28 AM #2
In the meantime I have prepared the schematic of the power supply section.
The BeagleBone will draw max 460 mA so I set the LM317 current source close to 600 mA. (570 mA)
Because the average current draw by the BBB is likele to be much lower I dit not really calculate 150% x 460 = 690 mA.
During playback and streaming I still will have plenty headroom left even with "only" 570 mA.
The current draw by the DAC and USB will be more stable so here I will calculate the full 50% extra for the current source.MPad -> BeagleBone Black + NetGear ReadyNAS -> Lindemann USB DAC 24/192 (XMOS) -> DH Labs Revelation -> NAD C162 -> DH Labs Revelation -> Odyssey Khartago Plus -> DH Labs Q10 -> Boenicke Audio W5
08-16-2013, 05:07 AM #3
- Join Date
- Jul 2011
- Blog Entries
This project rocks!
I have no DIY skills, so I just resort to buying esoteric gear with good results (battery cape + Acousence GISO lan isolator). The heatsinks are a neat touch, since the chips are going to get a lot warmer if the CPU is fixed at 100% (1 GHz). Still interested to see how the PS turns out :-)
08-16-2013, 05:51 AM #4
I just picked up the aluminium parts for the enclosure ... making an enlosure this way is really fun realising it cost only 11 Euro .. ;-)
MPad -> BeagleBone Black + NetGear ReadyNAS -> Lindemann USB DAC 24/192 (XMOS) -> DH Labs Revelation -> NAD C162 -> DH Labs Revelation -> Odyssey Khartago Plus -> DH Labs Q10 -> Boenicke Audio W5
08-16-2013, 07:07 AM #5
The Lindemann DAC is fitted with 3 pieces of 4-pin multi-color leds.
The color shown represents the sample frequency or "not connected" state.
I decided to take it another route and make a new LED design using the available signals from the DAC PCB run them trough a set of AND/OR ports and make it look (and function ;-) like this:
09-07-2013, 04:34 AM #6
Today I had some time to continue with my project.
Determine the mounting position of the DAC board and BBB on the centre plate af the aluminium enclosure.
The BBB will be hanging upside down in the lower compartment.
Using PC parts (the studs on which you mount the mainboard in a case) I thought it would be neat and look professional.
I measured the thread of the studs which appeared to be M3. I have cutting tools from M4 - M10 so I had to buy a M3 tap too.
I first drilled the holes for the BBB studs but during this porcess I realised I only had 4 of these studs ... the silver ones.
All other were the brass models which had different thread. Measuring these I guess they are 1/8 inch (= approx. 3,2 mm) for which ofcourse I did not have any cutting tap.
I drilled the holes for the brass studs with 2,5 mm too and used the drill too have the studs cut them selves into the aluminium with some pressure which worked quite well.
The power supply PCB's will be installed with the brass studs too. I will make 2 dedicated PCB's on each side for each component.
When drilling the holes in the edge of the DAC PCB I hoped I did not destroy any traces which I might have overlooked but now I am writing this topic my DAC is playing nicely installed on the bare aluminium so everything is fine.
09-07-2013, 06:12 AM #7
In the meantime I also drilled and installed the studs for the power supply boards.
Also the holes for the power and USB cable are prepared.
09-07-2013, 07:37 AM #8
09-07-2013, 01:11 PM #9
As an anti-vibration solution I have a piece op adhesive bitumen which I cut to fit and attached to the centre divider and top and bottom plate.
As I will not use the USB power from the BBB I cut a standard USB cable and use only the signal leads.
The 5 Volt needed for the USB receiver and XMOS chip will be clean regulated from the custom power supply.
The pins marked in red are the USB signal pins so the green/white leads will be soldered directly to these pins.
The pins marked in yellow are the USB power pins. Also the USB power will be soldered directly to these pins.
12-07-2013, 10:50 AM #10
It has been some time but I have made some progress ...
I have built the power supply boards and some more.
I also soldered the short USB cable to the receiver board of the DAC.
During testing when measuring the stability op the voltages I short-circuited the USB power at the receiver board by accident when my measuring pin from my DMM moved a little. After that the system still functioned but after a few power on/off cycles the DAC refused to lock to the USB input. After some tests I concluded the USB output was faulty ... not surprising after all.
I needed a new BeagleBone Black ... :-(
Ordering a new one had a delivery time of some weeks. Apparently the BeagleBone was very popular and the seller was out of stock. A week ago I got the new one so I could finally continue.
After installing the new BBB I first used an external USB cable (the earlier with my HTPC used Wireworld Starlight 2 mtr length) but when everything played fine again I soldered the silver USB cable direct to the USB receiver board of the DAC and WOW !! ... what a difference that made. Much more detail and the acoustic ambiance in the recodings was much more present.
The height of the power supply boards made me realise the aluminium side profiles would be to low to fit.
Today I had some wood prepared with some grooves to hold the three aluminium plates.
For max. RFI protection I covered the inner panels with aluminium foil.
The pictures speak for itself :-)
12-10-2013, 06:06 AM #11
On the XMOS board are some chrystal oscilators. These oscilators are high frequency so they probably emit high frequency radiation.
Being very close to the analog output stage I decided to make some screening made of aluminium foil covered with tape for electrical isolation. It is like a bag which I slip over the XMOS board.