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Gieseler Audio

Raspberry Pi Klein combo interest

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I have had this idea for ages & now a Stereonet member has quizzed me on it so I just want to get an idea of the interest in such a device.

The plan

A Klein II DAC but with a Raspberry Pi in place of the USB input board. I would probably get rid of the S/PDIF inputs as that will give me a more direct I2S runs & drop the cost a bit. The Rasberry Pi will plug directly into the Klein motherboard & be supplied with a nice beefy low noise 5v supply.

Sound quality should be very good as I would be supplying the AK4490 directly with I2S output from the Pi. To enable all the sample rates I would add a nice low phase noise clock. Obviously It's going to take a bit of R&D to sort the reclocking thing but I have all the gear & keen to have a go. I would leave the software/OS side of things up to owners to implement as the possibilities in that area are huge.

Summing up.

LMS or something similar running on the NAS

Ethernet connection to the Pi/DAC & control with a app.

What do you think?

I'm not locked into the Pi, the Beaglebone Black (easier to reclock) looks good but not nearly as much support as the Pi.

Very rough costing arround $800 or lower if I based it on the standard Klein (but no DSD)

At this stage I just want an idea how many people would be interested in something like this.

Fire away!

Edited by Gieseler Audio

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rastus   

Interesting, even interested... let me re-read (before I shove my foot in). :P

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rastus   

Extremely high interest: high, for those that do not possess the computer knowledge and skills and software configuration knowledge and skills required to setup a Pi (although this may be mute as they will have to get the software in there one way or another, and configure it). Maybe even high for those that do possess said knowledge and skill (not bragging, but I am interested in this).

Bypasses the need for a Raspberry Pi, and an added DAC (either as an addon board or external), and linear power supply... combines all these into one unit. Only one power socket required.

No need for S/PDIF inputs I would agree. Use USB, Ethernet cable or WiFi as inputs (acts as inputs and outputs).

The "nice beefy [quality built] low noise 5v [power] supply" is one area the Raspberry Pi lacks, so good call on that. You have that covered.

So what outputs from this device? Optical? Coax?

Will there be 'holes' cut into the unit to access the Raspberry Pi connectors? And/or the micro card slot especially? For changing the software used or configuration, without having to unscrew the unit? This may not be needed, because one could simply PuTTy into the unit to make changes to the software on the card. But that would rule out the simplicity of the unit (for the average user). If you understand what I mean.

Good call on the "...nice low phase noise clock."

"Obviously It's going to take a bit of R&D to sort the reclocking thing but I have all the gear & keen to have a go." <---- I say GO!

"LMS or something similar running on the NAS" <----- This would be the users responsibility I would think... so long as there is a network connection (Ethernet or WiFi).

"Ethernet connection to the Pi/DAC & control with a app." <----- Ethernet and/or WiFi (via a WiFi dongle, the user could add this onto the inbuilt Pi themselves, or you could add a USB connector on the back of the unit for this (or use the Pi 3).

As to "app", not sure I know what you mean by this? With RuneAudio, it has it's own UI APP. Anyway, plenty of APPs out there to control this type of configuration.

That's if you use the Pi 2B, but if using the Pi 3 then this has built in WiFi and Bluetooth and the price is very close to the Pi 2B. But note: With the Pi 3 there has been some concerns about the built in WiFi and Bluetooth regarding addon board DACs not functioning correctly (this may not be an issue with the Klein DAC).

"I'm not locked into the Pi, the Beaglebone Black ("easier to reclock") looks good but not nearly as much support as the Pi." <---- I am (or 'was') locked into the Pi, but... if the Beaglebone Black (being easier to reclock) is the better option, then that's fine too. Either way, what you are proposing is a 'Network Streamer' (based on the Raspberry Pi) with a built in Klein DAC... or is it the other way around, LoL! A Klein DAC with built in Network Streamer... that could be "DAC+NS" or "NS+DAC".

"Very rough costing around $800 or lower...." <---- Price looks about right. The Pi is usually chosen because of it's low price, but it requires work and effort to get it to a place that's acceptable in terms of sound quality.

"At this stage I just want an idea how many people would be interested in something like this." <-----  "If you book them, they will come." (Wayne's World 2) And, if that's all you wanted then I've wasted my time writing this response. Eeewww, but it's all in good fun.

Anyway, I do have more to say on this subject (don't I always), and I am very excited about this concept (that's why I may have repeated myself, or not made myself clear). Too excited to proof read and think longer about what I want to say. For now, in the words of Arnold Schwarzenegger, "I'll be back!"

Edited by rastus

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Loving all the input - thanks guys.

Rastus - you have brought up an excellent point regarding accessing all the Pi's ports.

For the set-up you really need a hdmi display connection & the micro SD slot so I  need to get all these on the back panel for easy access. Hdmi could easily be extended but I'm not so sure on the micro SD slot.

Maybe I should just have a hinged hatch in the lid - maybe not after all the flak the toggle switch copped!

 

 

post-112957-0-39230500-1464140930_thumb.

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dave1   

So the Pi will be sitting inside the case of the DAC? As the SD card slot of the Pi is on the opposite end of the USB port, how would you access the Pi to swap out the SD card?

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Correct David - the pi will be firmly mounted inside the case but with the Ethernet & USB sockets exposed on the rear panel via a cut-out.  I will extend the hdmi with a flying lead to a rear mounted pcb socket & hopefully do the same thing with the micro SD slot.

I just not sure until I do some testing regarding mico SD slot but can't really think of a reason why it would not work. That would give easy access to all the needed ports without opening the main case.

Edited by Gieseler Audio

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rastus   

Indeed... I use my Pi for movies (OpenELEC) and music (RuneAudio), thus far I have been swapping the micro SD cards depending on what I'm doing. But, and this is my personal project (one of), I'm close to finalising a dul-boot card that will have both OS's on the one card.... via selection at boot. Just to rule some things out, with OpenELEC I do not use a keyboard or mouse, I use the built in CEC via HDMI, perfect. And for RuneAudio I use remote access to control it, web browser, iPad, iPhone, etc.

But I degress... back to this... by being able to swap the card over I (and others) would be able to use this device to play music AND watch movies, via HDMI. An optical output connection (maybe even coax) for sound... I am of the opinion that optical can transfer 5.1 at about 48kHz (will have to confirm this).... and added HDMI. Also, as a sideline , RuneAudio now uses HDMI to display the RuneUI (have not as yet dabbled with this, but will be soon, not sure about the control mechanism it's using, ie keyboard, mouse, etc)... anyway, not really relevant.

I have seen many case designs that allow the Pi to be seated in such a fashion that access to the Pi's connectors is easy... three walls required. But could get away with only one wall, for the SD card only... with adapter cables to outside wall (of the unit case) for others. Still very excited, so I'm rushing here... please excuse any errors on my part. As to extending the micro SD card, I have seen such an extender (I'll find a link).

I'm not so sure of the "hinged hatch in the lid" concept, for.... prying little fingers of children, or prying big fingers of adults (the average user, for want of a better term) either. I will be back.... still not proof reading my posts. Too excited to do so. Did I say that already?

Edited by rastus

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buddyev   

I'm certainly in the market for a new streaming system to replace my airport express (and probably a new dac).

This would be a dac/streamer in one unit? 

I'm not familiar with Pi so I'm sorry be so dull-witted, whats the point of the SD card?

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Obviously It's going to take a bit of R&D to sort the reclocking thing but I have all the gear & keen to have a go.

 

:thumb:     It is right for a 'scope-wielding type of person to be doing this....  as these signals are too difficult to pin down for plug-and-pray.

 

 

 

whats the point of the SD card?

 

To get software onto the Pi.     Many type of operating system software can be run on it, toturn it into various flavours of streamer.   eg.   Squeezebox, MPD, NAA, Audio-over-IP, etc. etc.

 

 

... but I assume Clayton would plan to provide the Pi included with some sort of software, sopeople had an "out of the box" streamer experience.

Edited by davewantsmoore

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rastus   

The SD cards are finicky little things, so rooting around inside the case may not be a good idea....
BR198573_sandisk_sandisk_ultra_micro_8gb
SanDisk 8GB Ultra MicroSDHC Memory Card ($6.97)
http://www.officeworks.com.au/shop/officeworks/p/sandisk-8gb-ultra-microsdhc-memory-card-br198573

Even rooting around the back of the unit is difficult if swapping cards. If not swapping cards then all's fine, it becomes insert and forget.

An extender I found...
http://www.redtron.com/Extender%20Board/TFEX.html

tfex_b3.jpg

Or this...

$_35.JPG?set_id=880000500F

To maybe give you some ideas, heres examples of case designs for the Rapsberry pi...

$_12.JPG

And...

H6408.jpg

And...
audiophonics-raspdac-lecteur-reseau-rasp
That one above has a revolving picture of the completed unit, 360'...

http://www.audiophonics.fr/en/diy-dac/audiophonics-raspdac-kit-diy-network-player-for-raspberry-pi-20-dac-p-10511.html

More of the same unit...

audiophonics-raspdac-lecteur-reseau-rasp

audiophonics-raspdac-lecteur-reseau-rasp

Stop me if I'm over-stepping the mark, I am very excited and am throwing everything I can at you (did I say without proof reading? something I never do!)...

With their linear power supply connected...

btr_3.jpg
 

If I've gone too far, just tell me, and I'll delete these pics.... I will be back....

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greigw   

What are the advantages of having the Pi inside the DAC compared having the Pi on the outside?

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rastus   

Direct "I2S signal" connection directly between the Pi and DAC "for pure digital audio transfer and to improve the sound quality", and "reduce CPU load over USB audio solutions". Just a guess. Could be wrong, don't know enough about the technology.

 

http://www.collybia.com/mamboberry-hifi-dac/

 

Edit: Less power cords. Saves buying a Pi, and a DAC and a linear power supply separately. And, the most important reason... I like the idea.

Edited by rastus

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rastus   

What the guys at Collybia (a Greek mob) that created the Mamboberry HiFi DAC+ (with built in linear power supply on the DAC board itself) did was contact the RuneAudio developers to ask to include  a copy of RuneAudio software with thier "Mambo Media HiFi Player(kit)" (I would suppose also to try get software support for their DAC built into RuneAudio)....

"Our DAC will be called, Mamboberry... Can you plz send me a pm with your contact info?(address, etc)......"
http://www.runeaudio.com/forum/post5414.html?hilit=Mamboberry#p5414

Re RuneAudio forum: I am a member over there, and rather noisy about it too (could point you in the right direction if you chose this path)... don't know if that could help you.

This is all gobble-de-goop to me, but may mean something to you (ignore it if it's useless)...

The Mambo Media HiFi Player(kit)
"Special design ! – Low noise power supply & HD DXD 352.8Khz D.A.C. in one board !
The choice we did with SABRE 9023p chip DAC was the best for our goal. With the technology, “Time Domain Jitter Eliminator“ provided by SABRE and the high quality oscillators(low-jitter oscillator(Xpreso Fox) we use, we achieved the lowest noise level!
Just connect a 6 Volt 2A AC transformer(or 9V 2A DC) and the on board ultra low noise regulator will supply the RPi  board with clean linear low noise power....by Vasilis Tounas – sound technician"
http://www.collybia.com/mamboberry-hifi-dac/
Mamboberry.png

Pictures of their case design can be found on the link below (I can't link them here)...
http://www.collybia.com/product/mambo-media-player/#tab-description

 

Now Clayton, I hope I have not overstepped, or whatever... I really am interested in this project. I figured I'd throw as much as I could... to show you there is interest (from me).

 

PS: No 'proof readers' were hurt (or used) in this production. Not my usual, but boy did I get a major soft-on reading your concept post. Anyway, back to you. I'm exhausted.

Edited by rastus

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greigw   

Sounds like a great idea.

But what are the disadvantages of having the Pi in the DAC?

I use my cd player as a transport via spdif (rca) to my dac, so loss of spdif is one disadvantage for me.

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greigw   

Somebody mentioned a modular design previously in this or another thread. Could you offer a modular design dac, Pi, pre?

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rastus   

Oh, and the Beaglebone Black is supported by RuneAudio so I'm a happy-chappy. No love from OpenELEC for the Beaglebone Black (not supported). "Doesn't madda!" (Con the Fruiterer) Music is more important. I can always use my Pi for movies and the Klein-II-Pi (Klein-2-Pi, Klein-Pi) for music. "Bewdiful!" (Con the Fruiterer)

Edited by rastus

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nzlowie   

Clay, I thought the intention would be to make a standalone player.... If so you wouldn't need access to the sd card. Once setup with the player software its done. Also note i have the official 7" touch screen on mine and its works a treat with Rune, first software I've tried.

Sent from my D5833 using Tapatalk

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rastus   

Well this would be a "standalone player".... with the option (if the buyer so chose) to alter the software (usually done on a PC with a card reader because PuTTy and the Archlinux command line is just a bit too complex for configuration and updating)... and as RuneAudio and most of these software's don't have an internal 'button' to update (although the next incarnation of RuneAudio should have this feature, and there may also be other OS's that do, piCoreplayer, Max2play, etc)... and, what about SD card failure replacement (return to base?), and it does happen with the Pi... another option (that becomes very complex) is adding an SSD drive (price increase alert) to run the OS... the option to add a "7" touch screen" is not really needed if the Pi can be accessed via a web browser, but a nice idea (price increase alert), I do like it though.

 

Can I have mine painted with the Batman symbol on the topmost face of the case? Then I could stick the SD card into Batman's mouth! Ruuuuly cool! But seriously, I like this idea.

 

PS: Not the Batman thing, was joshing about that. Sorry, I'll stop posting... honest.

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Wow guys (where are the girls?) I had no idea there would be such a massive response.

Rastus thanks for your wealth of information & no you have not overdone it - keep it coming.

I think Greigw asked what was the advantage of having the Pi inside the DAC or disadvantage of it being on the outside.

The main reason for having it in the DAC is to get the maximum sound quality we can out of the little Raspberry Pi. To do this with the least amount circuitry & processing we need to directly take the I2S data from the Pi & feed it straight into the AK4490 DAC chip. It is best to keep the I2S lines as short as possible & without plugs, sockets,relays ect. The best way to implement that is have the Pi directly plug into the motherboard close to the DAC chip & that's what I plan to do. The other advantage is I will have a dedicated low noise PSU on the motherboard right next to the Pi to feed it top notch power.

Implementing the above two options should give us a very high quality audio possibly even better than the previous USB input.

Fingers crossed!

As the Pi has no MCK out I will have to add reclocking & may even add galvanic isolation on the I2S lines while I'm at it.

The whole concept is to keep the unit fairly basic but with top quality audio. Ethernet in - RCA audio out - balanced could be an option too.

Edited by Gieseler Audio

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