Raspberry Pi DAC Help!

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Hello!

I am looking to build my next project to pair with my amp. I built a LM3875 premium amp from audiosector and the picture is attached. I would now like to improve the audio coming from the iPhone that I am currently using. I have a Raspberry Pi B+ and a Raspberry Pi 2 and am looking at the different DACs available for the Pi. I am wondering if it is possible to have the digital music from my iphone sent to the Raspberry Pi DAC and then to the amp and then speakers. In this case I would use my iPhone to control the songs and playlists.

Again, iPhone->usb -> raspberry pi -> raspberry pi DAC addon -> analog to LM3875 -> speakers

So, is this possible to do?

Alternatively, should I have a USB data drive plugged into the raspberry pi as well as a wifi tongle to connect to the internet. I could then use my phone to access and control the music off of the USB drive.

Finally, what is the best sounding DAC?
1) Hifi Berry Pro
2) IQaudio Pi-DAC+
3) Lucid Labs

I would also like to build an enclosure similar to the amp enclosure and have it sit either on top or under the amp. For power supplies, should I build my own internal power supply instead? I do like the internal look on this site!
Review: Raspberry Pi 2 as Music Streamer | Part-Time Audiophile

Thanks ahead of time!

Peter
 

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I've recently started experimenting with the Pi2 as a player. Since I didn't have a decent supply I added a linear supply, which compared to the $3 charger I was using before was quite an improvement. The Pi doesn't offer much by way of voltage regulation so every little bit helps. I finally decided on an Apple charge to power just the Pi, it's as quiet as a linear supply and without the 50hz noise.

As for DACs, I haven't gotten around to the I2S interface, but the USB picks up my Audioquest Dragonfly and Benchmark DAC2 just fine. Hardware volume control is available on the former, not the latter.

The MPD based players are all quite similar to each other, basically differing in interface. You connect the media source to the Pi using Ethernet/WiFi or USB, MPD will store song information in its library, and the interface will allow you to control playback using a browser.

The issue is that when playlists grow very long, there is a lot of lag using mobile browsers. Also - and I don't know if this is because I come from a Windows/Foobar environment - the flexibility of tabbed playlists is sorely missed. I can agree that in all probability the sound quality of a Pi based system is very good. I cannot say whether it is better or worse than others, but it does sound clean and transparent, much beyond its price.
 
I've recently started experimenting with the Pi2 as a player. Since I didn't have a decent supply I added a linear supply, which compared to the $3 charger I was using before was quite an improvement. The Pi doesn't offer much by way of voltage regulation so every little bit helps. I finally decided on an Apple charge to power just the Pi, it's as quiet as a linear supply and without the 50hz noise.

As for DACs, I haven't gotten around to the I2S interface, but the USB picks up my Audioquest Dragonfly and Benchmark DAC2 just fine. Hardware volume control is available on the former, not the latter.

The MPD based players are all quite similar to each other, basically differing in interface. You connect the media source to the Pi using Ethernet/WiFi or USB, MPD will store song information in its library, and the interface will allow you to control playback using a browser.

The issue is that when playlists grow very long, there is a lot of lag using mobile browsers. Also - and I don't know if this is because I come from a Windows/Foobar environment - the flexibility of tabbed playlists is sorely missed. I can agree that in all probability the sound quality of a Pi based system is very good. I cannot say whether it is better or worse than others, but it does sound clean and transparent, much beyond its price.

Thank you for your response. In terms of power supply, I was looking at doing something similar to what is in the link in my original post. What do you think about that?
 
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The temporary supply I had was basically the same thing, a toroid with a LM338 and a bunch of capacitors. It worked well and seemed to be decent improvement over the cheap charger. It was a very tiny difference, mainly because my DAC is not powered by the same supply as the Pi.

I suppose of you are running the DAC off the I2S line, the supply quality and type have a more significant role. That said, it seems a bit counterintuitive to have something like the pi running off a big honking toroid. FWIW the Pi draws about 800mA all the time with no other peripherals running off the USB bus, just an Ethernet cable and maybe the XMOS USB chip on my DAC. So watch the input/output differential voltage because the regulator can run hot. Plan for about 10VDC.
 
The easiest way is an I2S DAC - I have the PiCobber and the HiFiBerry on two different Raspberry Pis (both first generation). I run Volumio on the Pis, and MPod on my iPhone to control. The music is on a USB disk on my wireless router, but you can also put the disk directly on the Pi.

It works well, both DACs sound great - at least as good as my Naim CD player, and it's nice having remote control.
 
The temporary supply I had was basically the same thing, a toroid with a LM338 and a bunch of capacitors. It worked well and seemed to be decent improvement over the cheap charger. It was a very tiny difference, mainly because my DAC is not powered by the same supply as the Pi.

I suppose of you are running the DAC off the I2S line, the supply quality and type have a more significant role. That said, it seems a bit counterintuitive to have something like the pi running off a big honking toroid. FWIW the Pi draws about 800mA all the time with no other peripherals running off the USB bus, just an Ethernet cable and maybe the XMOS USB chip on my DAC. So watch the input/output differential voltage because the regulator can run hot. Plan for about 10VDC.

Would it improve the sound quality by having a better power supply at all? I will most likely have a wifi dongle and a USB data disk on the pi working.
 
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Compared to a cheap, generic USB supply yes, but when you compare it to a high quality switcher or LDO, then it's quite tough to say.

The issue is that the Pi does all the conversion on board level. The 5V is passed straight through to the USB ports, but with a DC reverse protector. I believe they use a MOSFET body diode, not an actual rectifier. The 3.3V on the GPIO header has a dedicated switcher.

I believe you could run the Pi off pretty much anything you want, but it would be good to run the DAC off a separate supply as far as possible (some add-on DACs and audio boards allow this quite easily).
 
Compared to a cheap, generic USB supply yes, but when you compare it to a high quality switcher or LDO, then it's quite tough to say.

The issue is that the Pi does all the conversion on board level. The 5V is passed straight through to the USB ports, but with a DC reverse protector. I believe they use a MOSFET body diode, not an actual rectifier. The 3.3V on the GPIO header has a dedicated switcher.

I believe you could run the Pi off pretty much anything you want, but it would be good to run the DAC off a separate supply as far as possible (some add-on DACs and audio boards allow this quite easily).

Thanks! Do you know which DACs allow for external power? I can not seem to find one.
 
The easiest way is an I2S DAC - I have the PiCobber and the HiFiBerry on two different Raspberry Pis (both first generation). I run Volumio on the Pis, and MPod on my iPhone to control. The music is on a USB disk on my wireless router, but you can also put the disk directly on the Pi.

It works well, both DACs sound great - at least as good as my Naim CD player, and it's nice having remote control.

That is great news! I am leaning towards the IQaudio DAC. I am just unsure now about which wifi dongle to get and what power supply to use. Ideas?
 
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Thanks! Do you know which DACs allow for external power? I can not seem to find one.

This is one I was considering at one point in time (still am!):

Acrylic Case and HIFI DiGi + Digital Sound Card I2S SPDIF Optical Kit for Raspberry Pi 2 / B+ / A+ - Free Shipping - DealExtreme

The jumper near the power regulator can be removed. Some DIY is needed :D as it's also an interference suppressor. You can use that point to inject some cleaner power.

The Hifiberry Pro in your list specifically lists external power supply as a feature too! :) Not sure how it's implemented, but if you're a paying customer they will tell you how to go about it. As the page says, it will require soldering and void warranty, but you can't expect board makers to honour warranty for external (DIY!!) supplies.
 
This is one I was considering at one point in time (still am!):

Acrylic Case and HIFI DiGi + Digital Sound Card I2S SPDIF Optical Kit for Raspberry Pi 2 / B+ / A+ - Free Shipping - DealExtreme

The jumper near the power regulator can be removed. Some DIY is needed :D as it's also an interference suppressor. You can use that point to inject some cleaner power.

The Hifiberry Pro in your list specifically lists external power supply as a feature too! :) Not sure how it's implemented, but if you're a paying customer they will tell you how to go about it. As the page says, it will require soldering and void warranty, but you can't expect board makers to honour warranty for external (DIY!!) supplies.

I like the case!

I have been thinking, can the Raspberrry pi DAC be used passively? By that I mean can I connect via usb my iphone 4s to the Raspberry pi and play and control the music through the iPhone? Basically, I would like the digital signal to go from the phone, through the raspberry pi DAC, convert to analog, then to the amp. Is that possible?

Or, must I connect it to the internet via wifi and have a USB data drive with the music on it?
 
I have a raspberry PI with the i2s HIfiberry Dac attached, it very small as the DAC circuit board sits on top of the Pi. I have the Power supply that came with the Pi - just an average wall plug Job, - sounds fantastic.

Volumio is on the Pi and I mainly use MPD as Volumio willfind any music in your home that is on a shared drive and connected to your network.

ALSO- and I think you will like this, my girlfriend occasionally has her Macbook and Volumio will automatically play her itunes over airplay. my step son occaisonally turns up with his iphone and volumio will pick up music from his phone and play it through the Pi.

So the answer to most of your questions is YES

And it's mostly plug and play to setup

Stu
 
Wow! As good as a Naim CD5i? High praise.

The easiest way is an I2S DAC - I have the PiCobber and the HiFiBerry on two different Raspberry Pis (both first generation). I run Volumio on the Pis, and MPod on my iPhone to control. The music is on a USB disk on my wireless router, but you can also put the disk directly on the Pi.

It works well, both DACs sound great - at least as good as my Naim CD player, and it's nice having remote control.

The Naim players (every last one of them that I have heard and I've heard a few...) sound great. If the Pi DAC/Raspberry Pi sounds anywhere near as good then quite a complement.
 
I won't offer any advice about choice of DAC, or power supply, but I comment on your configuration questions:
iPhone->usb -> raspberry pi -> raspberry pi DAC addon -> analog to LM3875 -> speakers
can I connect via usb my iphone 4s to the Raspberry pi and play and control the music through the iPhone?
This idea is fundamentally wrong. Since you have specified a direct USB connection from the iPhone, this means that the iPhone is the digital audio transport, and the next component in the chain should be a DAC. In this case the Raspberry Pi, which (amongst other things) is also a digital transport, is completely redundant.

If you're happy to continue to use your iPhone as primary playback device, with direct USB cable connection, then it's certainly possible to connect directly from iPhone to a DAC, then to amplifier ... more information later. A Raspberry Pi is completely unnecessary. By adding an external DAC to the iPhone you will, depending on how good the DAC is, likely achieve a SQ improvement. Bear in mind that the music files on the iPhone are compressed, so this is a limiting factor.

But is this what you want? I suggest you sit down and do some thinking and reading on the subject. Do you want your iPhone to be the home music player? Or do you want to set up a music server/network audio system, accessing your iTunes collection from your desktop or laptop computer?
If yes to the 2nd option, then sure, a Raspberry Pi would be a decent choice of music server ... or actually music renderer, if it was to be configured to receive Airplay streams from your iTunes computer (as surfstu mentioned).

Back to the iPhone option: direct USB-audio connections from iPhone/iPad became easy only from the release of iOS7, so that's the base requirment for your iPhone. Prior to iOS7 the digital audio was encrypted, and could only be decrypted by Apple-licensed hardware, which was usually quite expensive. Even with iOS7 conventional Apple USB cables will not do the job - instead you need an Apple USB Camera Connection cable. Also you must be careful that if the DAC draws power from the USB cable, that this does not exceed the current limit of the iPhone or iPad. Good information here -
How to Connect Android, iPad, or iPhone to a DAC | JDS Labs Blog

You need to decide which path you want to take.
 
I have a raspberry PI with the i2s HIfiberry Dac attached, it very small as the DAC circuit board sits on top of the Pi. I have the Power supply that came with the Pi - just an average wall plug Job, - sounds fantastic.

Volumio is on the Pi and I mainly use MPD as Volumio willfind any music in your home that is on a shared drive and connected to your network.

ALSO- and I think you will like this, my girlfriend occasionally has her Macbook and Volumio will automatically play her itunes over airplay. my step son occaisonally turns up with his iphone and volumio will pick up music from his phone and play it through the Pi.

So the answer to most of your questions is YES

And it's mostly plug and play to setup

Stu

That is a really convenient setting! How does Volumio know to search other devices like your step sons phone and girlfriends macbook? Very cool software!
 
I have had very poor luck with getting Volumio to do what I want, which is streaming internet radio, AND a music server.

For that task, I have been using a squeezeplug pi setup.

SqueezePlug

This gives me a nice interface on my phone, and as long as I mount the Harddrives, I'm good to go.

Only way what I have found to reliably stream internet and serve up hard disk stuff.

Been toying with a windows pad set up as microCenter has them on for $79, and using I heart radio, but have not done the yet.

For me, the hardest part has been chasing hum out of the integrated amps that I put them in!

Dave
 
I won't offer any advice about choice of DAC, or power supply, but I comment on your configuration questions:


This idea is fundamentally wrong. Since you have specified a direct USB connection from the iPhone, this means that the iPhone is the digital audio transport, and the next component in the chain should be a DAC. In this case the Raspberry Pi, which (amongst other things) is also a digital transport, is completely redundant.

If you're happy to continue to use your iPhone as primary playback device, with direct USB cable connection, then it's certainly possible to connect directly from iPhone to a DAC, then to amplifier ... more information later. A Raspberry Pi is completely unnecessary. By adding an external DAC to the iPhone you will, depending on how good the DAC is, likely achieve a SQ improvement. Bear in mind that the music files on the iPhone are compressed, so this is a limiting factor.

But is this what you want? I suggest you sit down and do some thinking and reading on the subject. Do you want your iPhone to be the home music player? Or do you want to set up a music server/network audio system, accessing your iTunes collection from your desktop or laptop computer?
If yes to the 2nd option, then sure, a Raspberry Pi would be a decent choice of music server ... or actually music renderer, if it was to be configured to receive Airplay streams from your iTunes computer (as surfstu mentioned).

Back to the iPhone option: direct USB-audio connections from iPhone/iPad became easy only from the release of iOS7, so that's the base requirment for your iPhone. Prior to iOS7 the digital audio was encrypted, and could only be decrypted by Apple-licensed hardware, which was usually quite expensive. Even with iOS7 conventional Apple USB cables will not do the job - instead you need an Apple USB Camera Connection cable. Also you must be careful that if the DAC draws power from the USB cable, that this does not exceed the current limit of the iPhone or iPad. Good information here -
How to Connect Android, iPad, or iPhone to a DAC | JDS Labs Blog

You need to decide which path you want to take.

Great information, thank you! I have purchased an IQaudio DAC+, an official raspberry pi wifi dongle, and a power supply too.

I cant wait to get everything in now!
 
I have purchased an IQaudio DAC+
OK, that's good. You have obviously done some thinking, and made the decision to go with a music server/renderer.
There are several options now available to you in terms of how the RPi will access a music library, but it's clear you already have an iTunes music collection, presumably on a desktop/laptop computer, so the choice is rather straightforward to have iTunes act as the music library and Airplay server - as has been mentioned.
What hasn't been fully discussed is how you now control playback -

i) you can directly use the iTunes interface on your desktop/laptop computer.
or
ii) you can use your iPhone as a controller, by installing the "Remote" app -
Apps - Remote - Apple (AU)
This latter option is somewhat ironic, since your iPhone will be remotely controlling the same music collection which the iPhone already contains internally!

Alternatively you could buy a different (Apple) controller device, such as an iPad, thus freeing your iPhone for what it was primarily designed to do - make and receive phone calls!

Of course an iPad is a rather expensive device to use purely as a music controller, but it's also possible to do the same thing with an Android phone or tablet, with a suitable Android app installed, such as "Retune" -
https://play.google.com/store/apps/details?id=com.squallydoc.retune&hl=en
or "Remote for iTunes" -
https://play.google.com/store/apps/details?id=hyperfine.hftunes&hl=en
 
After some initial experiments with volumio I now have a squeezebox implementation (SqueezePlug) running on my Pi. It gives much more control over the music library, better playlist capabilities and there are some apps out there (I use iPeng) that are provide remote control on par (or better) than some of the high-end stuff from Linn and Naim.

My current hardware setup:
RPi2 > Hifiberry DiGi+ > dCS Puccini

This setup comes frightingly close to the Auralic Aries LE I tried as renderer.

Experiments with USB and SPDIF rto various DACs (Audio GD NFB-2, Cambridge Dacmagic+) showed a significant difference. SPDIF via the Digi+ sounded much better than USB. So much better that I sincerly doubt the USB audio implementation on the Pi....

I now plan to take it one step further:
RPi > I2S FiFo (from Ian) > dCS Puccini

Let's see if this can beat the superb Auralic Aries with femto clock that still sounds significantly better than the Pi/Digi+.

But mind you, the Pi solution is only 1/18 of the cost....
 
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