Post Sun May 26, 2013 9:20 pm

High Fidelity FLAC playback with XBMC and headphone amp

So I started this thread on Club Polk but wanted to post it here just in case someone was interested in it. I built a small mini-itx computer for the sole purpose of listening to FLAC & high-rez music at work with a USB headphone DAC.


The computer build part of the project is almost wrapped up so I thought I would start a thread here about it to run in conjunction with the thread at Club Polk.

Here is my last post in that thread. The full thread with pictures/failures/setbacks/thoughts can be found here (and I highly recommend reading up on it as its got a lot of good info that could save you time):
http://www.polkaudio.com/forums/showthr ... stem/page5

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I thought I would update this post as the system is for the most part done. I am pretty happy with the system baring some issues I will discuss later in the post.

I thought I would start by updating and listing all the system components I am using right now. There may be some changes but nothing major hardware wise. The system components are below:

Motherboard: ASRock A75M-ITX - http://www.newegg.com/Product/Product.a ... 6813157273
CPU: AMD A6-3500 2.1GHz FM1 65W Triple-Core APU - http://www.newegg.com/Product/Product.a ... 6819103951
Memory: 4 Gig Corsair DDR3 1333 - http://www.newegg.com/Product/Product.a ... 6820145278
Hard Drive: Samsung 1 TB 2.5" - http://www.newegg.com/Product/Product.a ... 6820145278
Case: Wesena ITX-6 - http://www.shop.perfecthometheater.com/ ... ITX6-B.htm
PSU: City Net 150 watt pico psu - http://www.frys.com/product/5974914?sit ... IN_RSLT_PG
Extras:
Noctua NH-L9a heatsink - http://www.newegg.com/Product/Product.a ... 6835608030
Noctua NF-R8 80mm case fan - http://www.newegg.com/Product/Product.a ... 6835608028
Silverstone Noise dampening foam - http://www.newegg.com/Product/Product.a ... 6811999222
Silverstone 80mm fan filter - http://www.newegg.com/Product/Product.a ... 6811999223
2 x Startech internal USB header to USB adapter - http://www.newegg.com/Product/Product.a ... 6812200294
D-Link DWA-160 USB card - http://www.newegg.com/Product/Product.a ... alParent=1
IR Sensor + Windows Media Center Remote
*Possible optional parts*
Sony Optiarc slot loading blu-ray drive - http://www.newegg.com/Product/Product.a ... 6827118072
Rosewill RHRC-11002 Remote and USB Dongle - http://www.newegg.com/Product/Product.a ... 6880101008

Interface: XBMC streaming FLAC and hi-rez audio, Pandora, etc
Headphone DAC/AMP: Audio GD NFB-5
Headphones: Beyerdynamic DT-770 32 ohms

Here are some of the roadblocks I have to getting things to work:

Controlling playback:

My ability to control the computer without a monitor was dependent upon the XBMC remote app being used on my iPhone. The app requires both devices to be connected to the same wireless network and it then works flawlessly. I have tested it at home and it works without any issue. It’s a pretty neat app. There is a wireless network at work that my iPhone connects to as well as my computer. The issue is that it’s got some sort of security setup that is blocking the iPhone and the computer from talking to each other. This requires me to use the Windows Media Center 7 remote and IR sensor I have to control music playback. That said I all I can control without a monitor is skipping forward and backward on songs. I have no way to browse my library at all.

I am researching options for getting around this. The main one I have found is simply to use a small 7” USB touchscreen monitor which would allow me to see everything that I am doing with the Windows Media Center remote and browse the library etc. I know XBMC has some issues with remotes so I am deep in researching what the guys at the XBMC forum are using for playback and what modifications they have made to XBMC to control them. The optional “Rosewill” dongle is supposed to be able to work with XBMC and also turn the computer off and on according to someone using the same motherboard as I have. If I go with that I will use that USB Dongle instead of the much larger IR Sensor I am using now that is connected internally using a internal USB motherboard header to USB adapter.

Volume control:

Currently I am planning on at work using the Audio GD NFB-5 headphone amp rather than the Meridian Explorer. The Meridian is ULTRA portable and super nice, but it requires you to control the volume via the computer. The Audio GD has an actual volume knob and is a lot more powerful than the Meridian. The Audio GD can also be used as a digital pre entirely on its own as its RCA outputs can be fixed or variable. This is nice because if I ever wanted to use something like AudioEngine A2’s at work I could use the volume knob on the Audio GD to control the volume.

The issue I am having is that after installing the Meridian drivers I have been having trouble getting the NFB-5 to work again. I haven’t had time to invest in looking hard into why but I am sure I will get it figured out pretty quickly.

Here are some of the things I am quite proud of:

Noise level:

This computer is SILENT in a normal working environment. Not only is it silent but it also runs VERY COOL. I am a HUGE fan of Noctua fans and while they are 2 or 3 times the cost of decent fans I personally think given their low noise levels in all their fans as well as their lifespan they are well worth it. I have been running 5 P12 120mm fans in my main system for 5 years 24/7 and they have had no issues. I just replaced the only non Noctua fan this month as it died. I replaced it with their newer line that now have a rubber mount built into them and its lowered my noise floor significantly in that system. So with this system by buying only the best Noctua parts and even modifying the CPU heat sink to make it work as well as keeping cables clutter to a minimum the entire system runs very efficiently and dissipates heat quite well.

I have also installed Silverstone noise dampening foam over all areas of the case possible. I don’t like this material nearly as much as the AcouticPak stuff I used in my main system, but it was cheaper and I just used a couple layers as I had a bunch.

Some area’s I am still looking at upgrading parts for and or needing to work on:

Power supply:I am still looking at power supplies to make sure I have the best of the best in my system. I know that by going USB to my DAC I am taking the possibility of getting noise from my computers power supply out of the equation, but I didn’t start this system to be anything other than no holds barred.

I/O Shield and GPU slot: I have a contact in Cincinnati who is going to powder coat the silver I/O shield and GPU slot cover to satin black so that they fit the color scheme I am going for.

Wireless: I am debating cutting a slot in the GPU cover to allow for the wireless card to be pulled out a bit to get better signal. I have found that the internal location I have it works great with most home systems and allows me to connect and control the device with my iPhone, however at work the signal is low enough I have to be able to pull it out and mount externally.

Exhaust: I am debating because I am OCD buying another 80mm Silverstone fan filter to go on the exhaust like I have on the intake

So here are some pictures of the system as its built now:

Top view with the HDD cage removed
*Note the cable management. I may replace the red zip ties with black ones at a later date as it drives me batty to have red ties sticking out like that*
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Side view:
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Closeup of IR sensor casing and overall cable management:
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Notched Hard drive cage covered in foam. The remaining part hanging at the bottom will allow for another 2.5” HDD to be mounted at a later date if more storage is needed.
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Hard drive bracket installed:
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Top cover with foam and fan filter installed:
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Exterior view:
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"Beauty is in the eye of the Beholder, Music is in the ear of the Listener" - ME
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