[SFDude]

I just am letting folks know I am back in town. I am very much looking forward to trying out the Pi stack as a possible replacement for my SB Touch.
Thanks to John and Letitroll98 for putting this tour together.

It's going out to you possibly on Wednesday (or maybe earlier) Wayne! I'm just going to wrap up when I have some extra more time to actually sit down and listen to it (I managed to get it set up but have had zero time to actually critically listen to it).

-dave

[Wayne1]

I received the Pi stack almost a month ago and just recently sent it on it's way to gregfisk.

I had a great deal of fun with the Pi stack. It opened my eyes to the world of Single Board Computers and all the various Hardware Attached on Top devices.

As mentioned, the Raspberry Pi came with the Allo Kali reclocker and Piano DAC HATs.

I first ran it with the Rune software that JohnR loaded. It had no trouble playing the USB stick and it sounded very smooth and natural.

I normally use a SqueezeBox Touch with EDO. I stream from a desktop with multiple hard drives over ethernet into the Touch. I attempted to connect the Pi into my network with the software JohnR suggested but I could not get it to see my drives.

I contacted JohnR to see if it would be okay if I used different software. He said it would be no problem. I recently tried out Roon and now that is all I will use. I found a newer image of Roon bridge called Ropieee which is very easy to install.

I got the Pi up and running using USB out to an iFi microDSD BL on loan from Pez. It sounded fantastic. I then contacted the author of the image to see if he could add the Allo Piano DAC to the devices used with the Pi. He was able to get the new image made and loaded the next day.

Here is where the unit really starts to come into it's own. Roon allows upsampling via software. The DAC chip in the Piano is the PCM5122 which will accept up to a 384 kHz/32bit signal. I set Roon to upsample to 384/32 and the best sound I have heard to that point in time started to come out of my system. Imaging was so much better. More precise. Highs were quite a bit cleaner. I have read others discuss benefits of upsampling but I have never had a piece of gear that would allow me to do it. Now with the Pi stack and Roon I could hear what everyone was going on about.

For most of the time I had the Pi Stack I just listened to my collection with an amazed look on my face. This $200 stack and software truly re-energized my interest in my music and gear. I tried running the Pi into the iFi but it was not at all happy with the upsampling with lots of stuttering. Without upsampling it played fine. I did prefer the sound of the Pi Stack with upsampling to the Pi going into the iFi with no upsampling on 16/44 material. The iFi started to get closer with higher resolutions.

I did try a different power supply with the Pi Stack and I did easily hear differences. The linear PS that JohnR sent along in very well built and sounds very good but better sound is able to be squeezed out of the stack but at a much higher cost.

I also ran an image of the Logitech Media Server called SqueezeLite designed for the Pi. I compared the Touch analog out to the Pi stack and the Pi was clearly superior in all ways. Better image, deeper and tighter bass and clearer highs.

For the $200 the Pi Stack is an absolute bargain in today's audio world. For a Cheap and Cheerful system, I cannot think of a better piece of gear to use.

The Pi Stack opened my eyes into the world of SBC and HATS. I really think this is a way for people to move into very high quality digital audio at a very low price. It is also a way to keep your system up to date at a very low price. In the very near future their will be quite a variety of different DAC boards along with reclockers and isolators. Allo is rumored to be working on a R2R DAC boards along with one using the AKM 4490 series. Another project I have heard of is using the ESS 9018K2M. Perhaps a HAT could be made for just the analog section so you could choose between solid state or tube outputs. This way if a new DAC chip comes along you can easily swap out the DAC HAT without having to change out the software or analog output section you have grown to love.

[SFDude]

This. Will echo the same and if you're inclined to actually put in some effort to build a Pi Stack, get the software installed and configured appropriately, you'll be rewarded for that effort. And be upgradeable too in the future!

-dave

For the $200 the Pi Stack is an absolute bargain in today's audio world. For a Cheap and Cheerful system, I cannot think of a better piece of gear to use.

The Pi Stack opened my eyes into the world of SBC and HATS. I really think this is a way for people to move into very high quality digital audio at a very low price. It is also a way to keep your system up to date at a very low price. In the very near future their will be quite a variety of different DAC boards along with reclockers and isolators. Allo is rumored to be working on a R2R DAC boards along with one using the AKM 4490 series. Another project I have heard of is using the ESS 9018K2M. Perhaps a HAT could be made for just the analog section so you could choose between solid state or tube outputs. This way if a new DAC chip comes along you can easily swap out the DAC HAT without having to change out the software or analog output section you have grown to love.

[gregfisk]

I do have the unit in the house and the box seems to be in good shape. When I get a change I will take it next door and see if I can get it running, probably not until this weekend.

Greg

[rotarius]

Too late to join the tour?  I just bought the Allo Boss and would love to compare to the Kali/Piano stack!

[Letitroll98]

Just send a PM with the required info.

[JohnR]

Roon allows upsampling via software

  I wasn't aware of that until reading your post. Makes the Pi even more viable. 

[Letitroll98]

Note that we've added a couple of members to the tour detailed on post 21.

[JohnR]

I do have the unit in the house and the box seems to be in good shape. When I get a change I will take it next door and see if I can get it running, probably not until this weekend.

Greg

Hi, any updates?

[JakeJ]

The Pi is now in my possession.  Have yet to carve out some time to get it going.

[gregfisk]

Hi, any updates?

Hi John,

Sorry for not getting to this earlier, I could explain why but not really a point in doing so.

I had fun with the little guy with the limited time I had to play with it, I only got it running using the thumb drive and thought it was pretty slick.

The sound is really good for the low cash layout and I'm sure if the full feature set was used it would be a great device, even at a much higher cost.

Since I didn't get a lot of time with it I don't really have anything to add other than if you are on a budget this thing is pretty special. In fact it's pretty special anyway for sure.

Hopefully JakeJ will be able to get more of the features working and report back more thoroughly than I am able to. 

Thank you very much John for making this happen and hopefully you have given people some food for thought.

Take Care,

Greg

[JohnR]

Thanks Greg

[JakeJ]

Pi Peregrination Tour -

My turn with Sparky the PiDACStream-a-saurus from Allo.com

I had a chance to play with the PI/DAC/Streamer that JohnR put together for this tour.  Consisting of a Pi Raspberry 2 single board computer mated to a Kali Reclocker and a Piano DAC, all from www.Allo.com.  All packaged in Allo’s minimalist case it is a tiny but quite capable package.  If you are on the tour I recommend you spend some time browsing Allo's website to learn more about this little jewel.

I set Sparky up on my main rig as it is the only working stereo I have.  The instructions John provides are all you need to get going.  Don’t do what I did and try to read between the lines on the setup.  You don’t need a keyboard, mouse or monitor because you just need to hang this off your network router and add power, open the browser on your PC, and simply type in the IP address your router assigned to it.  You will be presented with the Rune Audio interface and from there it’s mostly downhill.  Your PC becomes a remote terminal.
I mention again not to plug in a monitor, even though an HDMI port is available,  it's possible to damage the MicroSD card that is Sparky's HDD.  Sparky's power supply is only 8 Watts and does not supply enough power to drive I/O. 

I began with the USB stick with music files already installed plus I put some music I was familiar with on my Lexar 3.0 USB high speed memory stick to play.  This was easy to get working.  Next I tried to get a network drive attached to Sparky and had no success.  One needs to know what path and the format Rune Audio wants to connect to the network drive.  I tried several methods but no luck.

I made a feeble attempt to stream a source from the internet but since I have not started one of the services I failed miserably.  I tried a web radio station and signed up for Tidal but in hindsight probably should have tried Spotify as there is a button in the Rune app for it, but not Tidal.  Unfortunately I was too busy when I first got Sparky and tried it out in a last minute situation.  Not fair to Sparky and I apologize for that.

The sound quality of this little streamer was surprisingly good.  I noticed the music on the provided USB stick was a bit edgy but when I played files from my Lexar the sound was much smoother and cleaner.  I suspect I would have been rewarded with better SQ had I been successful at mounting a network drive or getting a streaming service working.  As it was Sparky acquitted itself quite nicely and I would say the quality of playback falls between my Adcom GCD-750 cd player and my old Perpetual Technologies P1a/P3a combo.

Perusing Allo's website I found their latest products which includes the new Vana plug-n-play player for a mere $169.  Allo bundles Sparky (Pi), Kali reclocker, the new Piano 2.1 DAC, Volt a TPA3118-based audio amp that provides 50 WPC (probably ~25 Watts of clean power), the Capacitance Multiplier (a sub-board to clean up power), and last is a 5 Volt wall wart, to create Vana.  This looks like the heart of a great little desktop system solution and certainly fits the Cheap and Cheerful HiFi mandate.  I would probably opt for a PS similar to what John included just more robust for sonics.

Thanks again,
Jake Jacobson

[rotarius]

I got the stack last week and got it up and running in no time since I have been using the RPI/Allo Boss combo for a while.  Initial impression is very positive.  I will make direct comparison between this stack and the Boss as well as my Sony UHP-H1 universal.  Detailed review to follow....

[rotarius]

Pi Peregrination Review:
I received the Allo stack which consists of the Pi board, Kali reclocker and Piano Dac all powered by a linear PSU.  I already have the Rpi/Allo Boss dac combo with Moode so patching it in my system was relatively easy.  My other high resolution source is a Sony UHP-H1 BDP (MSRP $350).

Set-up:  The stack along with the other sources were connected to the Jolida 3502 power amp via a BTE designs passive/stepped attenuator.  The amp has high input impedance and needs 1V for full power and so a good quality passive results in a clean and highly resolving sound without loss of dynamics.  The Jolida drives a pair of KEF R700.  Interconnects for all sources were Belden 8412/8402.

Listening:  I first listened to the supplied samples briefly and although I enjoyed Bach, Nine Inch Nails are not my cup of tea.  For serious listening, I started off with Rachmaninov - Symphonic Dances, Eiji Oue/Minnesota.  It is one the best recorded orchestral pieces I own and playing the 24/96 files through the stack was a pleasant surprise.  I was greeted by a large-scale sound that had some serious authority and power.  I knew right away this was a step up from the Pi/Boss combo I have.  Although the Boss is bassy, it did not have the same impact as the Peregrination stack.  Perhaps this was due to the linear PSU vs the SMPS of the Boss.  Overall, the Kali/Piano combo was tad cleaner and more detailed than the Boss.  Both easy on the ears but the Boss was a bit rounded at both extremes.  Now I was curious about how the stack compared to the Sony UHP-H1.  Switching to the Sony, the sound was a bit more forward with more detail and layering but with less bass heft.  The Sony just seemed more neutral and behaved like a true high rez source.  The Sony was just a tad better with layering an instrument separation than the Allo units. 
Next up was a bit of Jazz, Stimela by Hugh Masekela from the Dali Demo CD.  This is my reference track for a live recording.  Here the Kali/Piano stack was step up from the Boss with more dynamics.  The Sony was more detailed and projected the soloist a bit better.  The Sax and trumpet sounded more brassy with the Kali/piano than with the Sony.  To test vocals, I played Rhiannon Giddens - Tomorrow is my turn.  Really all three units did well here and my general impressions about them remained the same so I will not repeat.  Basically, the Kali/piano stack is not too far behind the Sony and if you have bright speakers, you might very well prefer it.  My KEF R700 are laid back so the Sony is a great match.

One thing to note, I did not upsample the files because the Rune version supplied did not have the feature or I just did not figure it out.  The Sony does have the DSEE upscaling turned on at all times, without it the player just sounds flat to me so it is my default.  I also tried my Boss with the linear PSU and the results were very nice.  The bass had more impact and overall the presentation was almost the same as the Kali/piano.  I would still give the edge to the Kali/piano, it just retrieves more detail I think.

Conclusion :  This stack offers a lot for the money.  It really is not embarrassed by anything under $500 or so.  I have tried quite a few budget dacs and currently have the MF V90 so I can speak from experience.  I plan on upgrading my pi source and will definitely get the Kali.  From what I heard, the linear PSU feeding the dac with good clean power without the PI micro usb port in the mix certainly helps a lot and is well worth the added cost.

[barryso]

Thanks again for this tour.  I've wanted to hear a modern dac to compare it to the older ones in the system and this was the perfect chance.

There's lots of audio gear in the house and it gets mixed and matched based on sonic signature and mood.  Currently there's a pair of 2 Pi Towers in the mix because there was a mistake when putting them together 10 years ago and once fixed they sound good - so I'm enjoying them for the first time.  Here's an explanation of how to put speakers together wrong:  https://audioroundtable.com/forum/index.php?t=msg&th=21360&start=0&

Currently there's a Jef Larson 2a3 amp in the system.  It's got a bit of a bump in the mid bass that makes the 2 Pi's sound a bit warmer than they do with other amps but it's very pleasant sounding.  The digital source has been a Pi/Hifiberry digi feeding a Bel Canto Dac2.  That combo is a tad bass shy which makes it seem a bit more open in the midrange and treble.  The treble also can get a bit strained as the music gets busy.

There have been about 3 extended listening sessions so far to get feel for the kali/piano.  It's got more bass than the Bel Canto and that bass is very nicely textured and nuanced.  Treble is down from my dac although that might be the increased bass in the Kali/Piano setup.  It's able to handle busy music without congestion far better than my old setup and it's treble doesn't get strident.  The dynamics are good and there's a nice sound stage.  It's a nice combo.

Since the 2a3 amp is warm sounding the addition of the kali/piano in the current setup pushes it a bit too far in that direction. That amp will get switched out for something leaner and we'll have another go at it.

In the mean time here are a couple of observations:

Comparing flac files on the flash drive compared to the same flac file on the network - the flash drive sounds better.  It may lead me to putting the music on a self powered hard drive in the future.

Comparing flac files to wav files on the network - the wav files sound better.  Yes, in theory they should sound the same.  The same thing was observed years back with the Squeezebox setup and I can't explain it but anyone who wants to come over to listen is welcome.

An older version of Moode software, on default settings, sounds harsher than the Runeaudio software.  Change the Moode kernel, it's scheduler policy, turn off the hdmi port, and set the cpu governor to performance and things sound far more similar to Runeaudio.  Not sure you could tell them apart at that point.

When you set Moode to over sample the music changes dramatically.  It gets more fluid and organic and warm.  Oddly enough it isn't something that sounds right with the 2a3 amp as it already sounds laid back.  But this is definitely something to listen to after switching amps.  Knowing this hobby it's either going to be magnificent or fail miserably. 

The other thing about Moode is that it was far more prone to having signal drop outs than the Runeaudio software.  Runeaudio plays flac and wav files off the network reasonably well but Moode has more drop outs with flac and can barely handle wav files.  The Moode software is over a year old so it probably isn't a fair comparison but it's still odd.

So far it's been mostly a win having the kali/piano dac in the system.  It may not be a giant killer (I'm not familiar with the sound of a modern, pricey dac) but it sure is a fine sounding combo for the money.

Hopefully the other amp will get to be in the system in the next day or so ...

[barryso]

TL:DR - It's a very good sounding music streamer.  Excellent given it's cost.  I'll buy one.

OK, some more notes on the Pi/Piano.

It turns out the the Rune and Moode software do sound a bit different. The Rune, as provided, is a bit more open in the mids.  The Moode varies depending the driver chosen for the dac.  So it's probably the selection of driver software making the difference in the sound between the different music players.

Swapped out the 2A3 amp for a conrad johnson preamp and a TPA3116 class d amp.  This combo is clearer sounding than the triode amp and gives a better viewpoint when changing back and forth from over sampling to non oversampling.  The oversampling adds a fluid, organic texture that's quite lovely.  The non oversampled tunes are more direct and precise.  It's almost like the difference between a traditional tube preamp and a solid state preamp - a huge difference in presentation but no clear winner on what is right.  It's worth hearing because you really might love it.

The clearer sounding electronics brought out the snap and dynamics of the Pi/Piano.  It'll do a thwack with the best of them.

My current setup is a Raspberry Pi with a Hifiberry Digi board driving a Bel Canto Dac2 or a tubed Paradisea.  The Bel Canto is clean and open sounding but it's a bit light on bass and the treble can be forward and a tad edgy.  The Paradisea tube dac is far nicer in the treble but a tad soft and rounded in the bass.  The Bel Canto listed for about $1300 in it's day and the Paradisea was in the $600 to $800 range.

In the defense of the two older dacs, the old Pi/Digi combo isn't being driven by a linear power supply and the Digi board is also a few years old (and newer boards have jitter reduction and power filtering on them).  It isn't really a fair fight but thats the gear that's been in the system for a few years.

As things are now the kali/piano sounds better than either of the older dacs.  Bass is strong and it's tight sounding for kick drums and loose and nicely textured on the upright bass.  Mids are clear, as is the treble, and the harshness during complex music isn't there like on the old dac.  It's a dynamic, nice sounding music player.

Kali/Piano Dac Pros

Nice, tuneful bass

Good sound stage

Nicely dynamic

Clear, clean presentation even during frantic music

Oversampling ability

Really affordable

Cons

It's not sweet sounding like tube gear, if that is your preference.

The linear power supply sent on the tour can get very warm.  It's not hot enough to be dangerous but it's probably not something you'd want to leave on when not in use.

Since my experience with modern dacs is limited it isn't possible for a direct comparison with other modern dacs.  But the kali/piano combo works far better than expected against the older gear in the system (and these were very well received dacs in their day).

More kudos for sending this out on tour.  These Pi/dac combos had gotten my attention but I'd never pulled the trigger on them because of their low price tag.

I like it and will buy one.  No idea if it'll be this exact setup or if it'll be the Piano 2.1 (that some claim sounds great in dual mono mode) or the Boss dac that is also mentioned frequently.  Anyone have a preference?  Please chime in as it's a brave new world out there.

[JohnR]

Thanks JakeJ, rotarius, barryso, great reviews 

I knew right away this was a step up from the Pi/Boss combo I have.  Although the Boss is bassy, it did not have the same impact as the Peregrination stack.

Interesting to read that, I imagined from reading the Boss copy it would be the other way (glad I was wrong  )

One thing to note, I did not upsample the files because the Rune version supplied did not have the feature or I just did not figure it out.

I'm not sure if it's in Rune Audio but in the past I've found the RPi doesn't really enough grunt for this kind of task.

[JohnR]

Comparing flac files on the flash drive compared to the same flac file on the network - the flash drive sounds better.  It may lead me to putting the music on a self powered hard drive in the future.

Interesting.

When you set Moode to over sample the music changes dramatically.  It gets more fluid and organic and warm.

Oh, I guess my earlier comment about the RPi not having enough grunt for upsampling was wrong... 

It turns out the the Rune and Moode software do sound a bit different. The Rune, as provided, is a bit more open in the mids.  The Moode varies depending the driver chosen for the dac.  So it's probably the selection of driver software making the difference in the sound between the different music players.

Interesting. Thanks for taking the time to compare!

The linear power supply sent on the tour can get very warm.  It's not hot enough to be dangerous but it's probably not something you'd want to leave on when not in use.

Yes, perhaps I was a little too frugal with that (trying to keep Int'l postage cost down). The same vendor has units with more power.

[rotarius]

JohnR, I now have a 2.5A linear PSU feeding the Boss/PI stack.  I also have a usb hard drive connected to the Pi via a powered hub.  Bass is definitely tighter with more slam but I still feel it is has a tad less impact than the Kali/Piano.  I am convinced powering the dac via the Pi is a drawback of the Boss.  The next step is to try Rune with this setup although I am quite happy with Moode.  Absolutely no issue with sox resampling to 32/384.  Sounds sweeter that way but does not sound as crisp as the original sample rate.