Raspberry Pi as headless streamer

[tomek]

Thanks tomek, that script has peaked my interest. I did a little bit of poking around with it last night. I'm using the SPDIF out of my HiFiBerry card rather than the USB output so I didn't disable the i2c outputs, but I guess there are other things I can probably kill off, like USB for instance (unless it shares the bus with the SDCARD I guess). That's got me hooked and I want to learn more about how this works and see what other optimisations can be done, as much from a geeky Linux tinkering project as for any gains in audio quality. Any more tips are appreciated.

Just play some music, login on your pi and try to remove some kernel modules or kill some processes. If you still can play music and change tracks etc, than is OK.

One more trick - use the original squeezelite from Adrian Smith (first on the list in pi www configuration page), and not the one from Ralphy (unless you really need it). The squezelite from AS is using much less RAM and little less ressources.

In the squeezelite configuration page you can set priority to "70" and load only those codecs which you really need - for example only "flac,mp3".

Also try to lower the alsa buffer from standard 80 to 40, smaller buffer sounds better, don't ask me why ... To small buffer can cause x-clicks, just try the lowest value without x-clicks in your configuration when playing 24/96 or 24/192 files.

 

[lovejoy]

Brilliant - All rings bells from when I was using the Squeezebox Touch. Lower buffer settings always had a positive impact on SQ. Funnily enough I switched back to the other Squeezelite version having been using Ralphy's version before I upgraded to 1.17a last night, so I'll run with that and see how it goes. It was a bit late for a good long listening session last night, but I've got a lot to have a play with over the weekend now.

Many thanks

 

[mudlark]

There are many out here who do not accept that getting silly with the size of the OS is worth anything at all. The piCorePlayer is small as it is, that being most of the point.

 

[tomek]

size matters

 

[russel]

Hi has any one who has played with rune audio got the WiFi to connect on startup? It uses arch Linux which I am not familiar with, I am guessing that there is a file that needs editing somewhere.


's ok found a link

http://thisoldgeek.blogspot.se/2014/04/easy-set-up-for-wpa-wireless-in-arch.html

 

[MarkW]

Tomek

Can I just ask why you are using the WaveIO with the Pi and your BII?

I assume you are using USB out of the Pi?

I strongly suggest you try ditching the interface board and pull I2S direct off the Pi into the Buffalo. picoreplayer supports this very well and it is a leap forward sonically.

(Of course, if you've tried it and not got the same kick I get from this configuration I will just crawl back under my stone...)

Mark

 

[tomek]

Tomek

Can I just ask why you are using the WaveIO with the Pi and your BII?

I assume you are using USB out of the Pi?

I strongly suggest you try ditching the interface board and pull I2S direct off the Pi into the Buffalo. picoreplayer supports this very well and it is a leap forward sonically.

(Of course, if you've tried it and not got the same kick I get from this configuration I will just crawl back under my stone...)

Mark

I am to lazy to change it. WaveIO was necessary for SBT with EDO plugin, than i took PI and since few months i am planning to to use PI-I2S-Buffalo, but there is always something else to do ...

 

[john.luckins]

I don't know what supply(s) you are using for the Wavio and Pi at the moment Tomek but it is also worth putting the very best one on the Pi once you have removed the Wavio, linear if possible.

John

 

[Julf]

I don't know what supply(s) you are using for the Wavio and Pi at the moment Tomek but it is also worth putting the very best one on the Pi once you have removed the Wavio, linear if possible.

Even if you aren't using the Pi analog output? How does the power supply affect the digital output of a Pi?

 

[tomek]

I don't know what supply(s) you are using for the Wavio and Pi at the moment Tomek but it is also worth putting the very best one on the Pi once you have removed the Wavio, linear if possible.

John

@John

I tried different ps wit Pi - Super Teddyreg, regulated battery and standard switched 5v usb ps.

IMHO best sound is with Pi powered by Super Teddyreg very closed followed by regulated battery. Switched ps is making sound harder and more digital, maybe some hf digital noise from switched ps is reaching the system in some way.

WaveIO is powered by Placid ps from Twisted Pear Audio.

@julf - no, i will not do abx tests

 

[john.luckins]

Even if you aren't using the Pi analog output? How does the power supply affect the digital output of a Pi?

Evidence and proof I do not have as I don't own the necessary test equipment but...

Power supply noise may have a small effect on the Pi's jitter in the digital domain but in my opinion the reason for using a good isolating power supply for any digital gear is to stop switching artefacts finding their way onto the mains and interacting with the other mains supplied audio equipment. If you don't believe me then try putting something like an Ethernet extender or a switched mode phone charger onto the same mains spur as an all analogue audio system. The effect is not subtle.

My son is always leaving our BT Broadband extender that he uses with his TV powered up and I can tell when he has within a few seconds of the first track I play in my music room.


John

 

[NRWler04]

Did anybody get it managed with a UPNP Server and a control point like KINSKY or something else?

 

[Julf]

in my opinion the reason for using a good isolating power supply for any digital gear is to stop switching artefacts finding their way onto the mains and interacting with the other mains supplied audio equipment.

Wouldn't it make more sense to put the filter on the analog equipment instead - that would help isolate it from all the line-induced noise, irrespective of the source?

BTW, I do have the measurement equipment, and have been debugging power line HF noise for the last 15 years as part of a bunch of projects that used powerline communications. Yes, there is a fair bit of HF there, but most equipment is pretty immune to it. There are of course always exceptions.

 

[darrenyeats]

Wouldn't it make more sense to put the filter on the analog equipment instead - that would help isolate it from all the line-induced noise, irrespective of the source?

I've not perceived good results with that. I don't know why. It's not that easy to blind test, and I haven't blind tested it, so bear that in mind.

I read this a while ago on SOS: "Mains filters commonly 'backfire' by coupling noise into the equipment, which is exactly what they're supposed to deal with"
http://www.soundonsound.com/sos/jul03/articles/mainsproblems.asp

Also, some suggest the supply impedance can be affected.

However, I am not sure about either explanation - I'd appreciate your comments! - I just know I haven't liked it when I've tried it.

 

[Julf]

I read this a while ago on SOS: "Mains filters commonly 'backfire' by coupling noise into the equipment, which is exactly what they're supposed to deal with"
http://www.soundonsound.com/sos/jul03/articles/mainsproblems.asp

Yes, traditional T or π filters with capacitors between the two mains poles and the earth lead can interfere with "floating" differential inputs and grounding schemes.

Also, some suggest the supply impedance can be affected.

Also true, in case the filter has a series inductor/choke, but that is only an issue with power amps.

I still think the fight against HF mains noise by isolating the digital components is futile, just because pretty much everything contains some sort of digital and switching circuitry these days. An analog sound system that is sensitive to mains-borne noise will also be affected by wifi, dimmers, phone chargers etc...

 

[darrenyeats]

Hi Julf, it's just me and wife in the house, the main system is upstairs and I can pretty much control what's on the upstairs ring. All the SMPSs that stay on when I'm listening are collected in the study, and I use an Marmitek FM10U to quarantine those. The only thing left is the Touch's SMPS, and I have another FM10U on that.

However, that still leaves wi-fi, other RFI, and also I'm not sure how much HF from other rings is actually attenuated via the CU. Or indeed how much HF makes it from the street. You can't get there 100% - agreed - but I think it helps.

 

[Julf]

Darren,

The Marmitek FM10U is indeed a good filter at a reasonable price. I remember I almost got booed out of a certain (commercial) computer audiophile forum for suggesting cheap X10 filters were just the same inside as very expensive audiophile filter devices.

 

[tomek]

So, today i connected Buffalo II with I2S directly to Pi instead of USB connection with WaveIO. It sounds good, but i have to do some more tests. It seems, that they are some clicks when i am changing from 16/44.1 to hd files.

 

[Bemused]

Hi tomek, my good friend themystical and of this parish is running RPI via I2S to a Saber 9018. It's also something I'm considering as my Joggler has taken a propensity to crashing if left in standby since a squeezeplay upgrage earlier this year.
I save lots of regulators if I junk the Joggler and WaveIO, reduce complexity and real estate footprint.
How does SQ compare for you?

 

[MarkW]

So, today i connected Buffalo II with I2S directly to Pi instead of USB connection with WaveIO. It sounds good, but i have to do some more tests. It seems, that they are some clicks when i am changing from 16/44.1 to hd files.

For me the sq is extremely good, much better than any USB implementation. I also got some savage clicks changing sample rates. I converted everything to one rate - I convolved my entire library using a room correction filter so I combined the two operations - problem solved.

Even with the odd click i would perservere. I have a Beaglebone Black, but it has problems locking with the Buffalo, so will wait until the TPA Botic comes out. My RPI has run for months without issue.

A great source, no doubt.