[abartels]

 

  For the ones who finds my Raspberry Pi 3 + Hifiberry DAC+ Pro project interesting:
 
After 5 days of burn-in time I have to conclude that "first impressions", until now, FAR exceeds what I've expected!!
 
What I did:
 
1- I took a basic RPI3
2- I took a HifiBerry DAC+ Pro and soldered a 2-pin header for external 5V power, and a 5-pin header for I2S output.
3- Mounted HifiBerry DAC+ Pro on Pi3's top
4- From Hifiberry website I downloaded latest installer and installed PicorePlayer for DAC+Pro on MicroSD card
5- Connected I2S to an older AK4495SEQ dac
6- Powered RPI3+DAC+ Pro with ONE 5V (diyinhk 0.8uV ultra low noise psu), so NO power input thru RPI's Micro-USB input
 
Things to consider:
 
The AK4495SEQ dac I used for this test was a previous one I used before I started my "Monster Dac project".
This dac is sounding very well, but has an integrated power supply on board, it's a very big difference in SQ in comparison with my "Monster Dac"
It's native SQ (connected to diyinhk isolated Xmos - just as in "Monster Dac") is a much less open sound character, less detailed and more compressed soundstage.
Low frequencies are not that detailed, mid frequencies are not as natural, and it is not that airy (black around voices and instruments).
 
On this AK4495SEQ dac I used a NEW "simple LME49720 - plastic version" opamp as output stage. This one hasn't burned-in yet too.
 
 
The previous impressions:
 
Listening to this set during the past days was not that good at all, at least, in comparison with my "Monster dac". It changed every day in a positive way, but it didn't please me at all.
(Don't forget that I am used to a very open soundstage, very natural sounding, very airy, just better than any analog I have ever heard, with massive Bass control which reaches to the
deepest registers I've ever heard (and felt...))
The soundfield was a bit fuzzy, no pinpoint precision, lack of bass control - but more powerful deep-bass. Voices seemed to sound different, not sure how to explain.
 
 
So, how did the RPI perform yesterday, after 5 days of burn-in time (needs at least 7 days):
 
What I heard yesterday was amazing. I didn't expect this at all. It seemed that the soundstage had widened, A LOT, maybe even wider than my monster dac!
There were several occasions where I heard lot's of phase-tricks in recordings, sounds which seemed to went out of the room, behind my head, everywhere!
There wasn't any listening fatigue anymore, pinpoint precision was almost as good as my monster dac, bass was VERY deep and powerful, but still lacks control.
 
But, what amazed me the most was it's sound character in total, not sure how to describe it, it's like, when comparing to my monster dac, the sound is more massive,
it surrounds you and it seems voices have much more body and impact. It's almost as if my monster dac is sounding pinched, more like a studio recording, while RPI is more
like a live concert, more rhythm and pace, it's just there!
 
I can't imagine how it can sound when properly powered, fully burned-in, and connected to my monster dac instead if the isolated USB XMOS I've built in.
 
I expect bass control to be better in the coming days because I know this opamp really needs it's burn-in time, and pinpoint precision and details will also gain.
 
These are wild days in Audioland, heard a lot of "rumors" of using rpi for audio, but now I know why, it has a phenomenal potential, and, I will explore those completely 

 
 
To be continued.....

 
After 7 days of burn-in I listened again to RPI and DAC+Pro.
 
It really sounds VERY good!
Of course it's not that airy as my monster dac, and also bass control is less, but that is something which is inevitable when using this AK4495SEQ in comparison to my "monster dac".
 
It still has a very wide soundstage, very 3-dimensional sounding, and it has a beautiful "punch", full body. 
 
I couldn't wait and powered 3.3V and 5V for DAC+ Pro external. This improved it again. It's a combo I could live with, definitely!
 
Very curious how it would sound in combination with my "monster dac", but that has to wait since I sold my "monster dac" to a friend of mine.
 
Since the DAC+ Pro uses mediocre TCXO's from ExpressO, it can't reach the best quality. And, sadly those tcxo'x can't be replaced very easily because they have
an on/off function. This means I would have to design a relay board before I could use NDK's.....
 
I will investigate this further, I'm very eager to try the Ian Canada FIFO II - Isolation board - Dual TCXO board, this should bring it to an absolute phenomenal SQ level.
The Ian Canada solution is independent from quality of clocks at it's input because it rebuild / regenerates everything completely new. But it has it's pricetag....
 
 
Regards,
 
Alex

 
Comparison "Monster Dac" with USB - isolated XMOS - I2S interface VS Low Cost AK4495SEQ Dac with RPI3 - DAC+Pro - I2S interface:
 
Setup:
 
1- HP Probook i7 - 16Gb RAM - Server 2012 - 2x 250 GB SSD - Audiophile Optimizer - JRiver as player - connected with USB to "Monster Dac"
 
2- HP Probook i7 - 16Gb RAM - Server 2012 - 2x 250 GB SSD - Audiophile Optimizer - LMS server (Logitech Music Server)
 
Both JRiver and LMS server running simultaneous on HP Probook.
 
Both "Monster Dac" and Low cost AK4495SEQ Dac use LME49720 as output stage.
 
 
To begin with:
 
I bought the low cost Chinese AK4495SEQ last year, just to check out the performance and sound characteristics of AKM AK4495SEQ chip.
Since I wanted to build a new dac I could decide whether this chip had a sound character I liked and if I would base my new dac design on it.
 
This little baby performed very well, but in it's stock version it was not as airy as I had in mind, so I started to mod it with lots of Nichicon FG caps,
Cree diodes, different opamp as output stage and more. At the end it sounded fabulous, especially when I connected Diyinhk Isolated Xmos to it.
The design of this dac incorporates 1x psu for output stage, and 1x psu (with several regulators) for Digital section.
 
Since it's fabulous performance I decided to build my new dac, based on this AK4495SEQ chip.
 
I started designing and building and eventually finished my "Monster Dac"
 
First listening sessions I was amazed about it's airyness, bass control, big deep wide soundstage, lots of blackness around voices and instruments.
It was a huge step forward from the little baby.
 
So, where are we now, today?
 
I connected both dac's and played 2 albums on them, running simultaneous from HP Probook.
If I wanted to switch between dac's, I only had to switch between them on my pre-amp.
 
To begin with, they sound almost identical!!!
 
- Monster Dac has a little better bass control (and definition in it's lower frequencies), it's a tiny bit more airy, and it seems (not 100% sure) if it's more quiet, more black around voices and instruments.
 
- RPI has better vocal body and seems to have more 3D artifacts. It's bass output is more evident.
 
The two are VERY close to each other in this setup.
 
Conclusion:
 
Since low cost AK4495SEQ performed incredibly different when using isolated XMOS, it couldn't walk in Monster Dac's shadow, I have to conclude that:
 
RPI3 + DAC+ Pro > I2S output > based on PiCorePlayer and LMS server, is running circles around isolated xmos solution.
It's a VERY good performing solution!
 
AND
 
Keep in mind, RPI3 + DAC+ Pro together cost around $100. Software (LMS server and PiCorePlayer) are freeware.
 
Isolated XMOS interface cost about the same, but it needs:
 
1- Very stable OS and drivers
2- Optimized OS for Audio only
3- Powerful CPU
4- Needs to pay for Player software if one wants to remote control it with Graphical Interface on iPad or Android device
5- Needs optimized USB port on PC
6- Needs USB optimizing equipment like Intona / Regen / iFi purifiers and others (which will let you break the bank.......)
7- Needs high quality USB cable (which will let you break the bank.......)
 
Keep in mind, I also installed LMS server on my Daily work laptop, which I am typing this review on.
I connected PiCorePlayer to this LMS server (it finds it automatically in the network) and played music from it.
There was NO sonic difference between Setup-2 and this setup!!! So, NO need for expensive hardware to run LMS server!!!
 
Second thought:
 
You can use RPI3 + DAC+ Pro in every room in your house, if you have network connection. You can use same LMS server, and, even Analog output sound quality of RPI3 + DAC+ Pro is rather good!!!
I suppose that there are many expensive dac's out there which perform much less than this little baby! (if connected separate psu's the way I did).
 
Final thoughts:
 
I will have to modify my Monster Dac to replace it's I2S interface with RPI3 + DAC+ Pro combo, more on that next week or so 

 
Last word:
 
Since this RPI3 + DAC+ Pro combination is performing that well, it asks for the best of the best, which is Ian Canada's FIFO II solution with Isolation board and Dual XO II clock board.
I ordered them today, so, let's have some fun the next weeks 

 
 
 
Wish you all a prosperous week 

 
Alex

 

[prot]

I see you are fighting hard against the USB gremlins  ... and looks like you are close to announcing a big victory

And btw, MSB is selling an 'upgraded' USB input-board for about $2000 ... your improved no-usb solution should be worth at least $1000 more

 

[Caper]

   
Looks great except the "El cheapo cable for data transport". That cable matters too. I would go with something at least as good as the Supra.
 
Oh, and a linear PSU will definitely help on your NUC2. But it's the top priority here because they are expensive. Worry about everything else you listed first. Just my opinion.

Yeah, I will let the F1 settle along with the Intona.
Already picked up another Supra USB cable.
 
Seen a couple of nice LPS but they are indeed pretty expensive.
Because the NUC runs on 19V I will try out to run it from pure battery power.
If that improves SQ much I might add a LPS later.
 
Thanks!

 

[abartels]

I see you are fighting hard against the USB gremlins  ... and looks like you are close to announcing a big victory

And btw, MSB is selling an 'upgraded' USB input-board for about $2000 ... you improved no-usb solution should be worth at least $1000 more

@prot
Hahahahaha, yessss, victory is mine, hahahahaha
 
 
@ALL
 
You know, since I used Server 2012, in combination with AO, I was VERY pleasant surprised about it's SQ. Even more when I used DualPC setup with JPlay.
Then I started with investigating USB-DDC, and it seemed it sounded much better than my expensive PC Audio-Card with SPDIF-out.
So, it was DDC I was putting my efforts in. Suddenly the USB-regen hype started, and I must admit, those devices DO make a difference.
But, since they ALL do, and since they STILL do if you put several in series, in series with purifiers, and all those other miracle devices, using usb-cabling for which you can buy
a whole NAS to store your complete music collection on, it got me thinking.......
 
If SPDIF signal was that kind of "Fragile", it would have been abandoned years ago. I know, there's professional use of USB too, but, look at what they are using.....
and what does it all cost,,,,,
 
Of course I can't deny I2S isn't meant for external usage, but still, if implemented the right way, and if using good quality (shielded) connection wires, it still is the best way to go.
Why (I hear people thinking,,,,), why oh why?
 
It's quite simple,,, (and I know, there are LOTS of commercial guys who LOVE to tell you a lot of gibberish to convince you I2S is s**t, maybe they do profit in some way or the other from.....??)
 
I2S is chips internal language, they talk to each other in I2S. Lets say your native language is English, you want to tell a story to a friend of yours,but you only have the option to tell it to a Chinese guy, a translator,
who in turn will try to tell it to your English speaking friend.
So, what happens is this:
You tell your story to the Chinese translator, the translator tries to understand what you are saying and tries to tell the story, in his best English, to the English guy......
The English guy is trying to understand what the Chinese translator is trying to tell him...
 
Does this sound familiar?
Hmm, is it possible there COULD go something wrong, OR, is it evident that there WILL go something wrong? 
 
 
I am exaggerating right now, but you get the drift.....
 
 
If, and ONLY IF, you follow design rules, and keep I2S signal wires as short as possible, using U.FL wires for internal usage, or external
VERY GOOD SHIELDED cabling, as short as possible, you will profit from I2S.
 

 
For internal usage, it still is BEST option.
 
So, if you could find a solution to incorporate a very tiny small pc including directly I2S output, which also included music player software which directly could connect to a music server,
that music server could be a NAS or a simple laptop, and it's I2S quality could be very very good, could it be that this solution would bring you a very high SQ?
 
I have the answer: YES IT DOES
 
 
The quest has just begon, and I already am miles ahead of where I left off (USB).......

 

[auvgeek]

  Finally got around to modding a Breeze DUU8 with crystek 957's. And it sounds fantastic. I want to spend a little more time and compare with my AGD DIU8 with NDK's but it's really damn close. Surely a nice bump in SQ over the stock JYEC gold clocks. Those obviously have inflated specs. The soundstage on the breeze is surely improved and a touch more bass texture/control yet a touch on the high end of clarity with no hints of distortion. 
 
This mod went quite well. Here are a few photos of the process.

 

Spoiler: Warning: Spoiler!

 

 

 

 

@bimmer100 modded my Breeze DU-U8, which I lent him partially so he could review it and we agreed that he should mod it while he had it there. It sounds SO good. The Crystek 957s seem to improved the soundstage and bass the most. The soundstage is obviously wider with a bit better imaging than before. That bass though! It seems to dig deeper with more punch (i.e., better dynamics) while still being tighter and more detailed than before. The highs are also clearer and more detailed, while still retaining the laid-back, non-fatiguing nature of the stock Breeze. Keep in mind my impressions are with the stock power cord, as my Graphene Extreme PC is currently being shipped back to me from my parent's house. But ~$100 for the clocks and dip14 sockets/boards seems definitely worthwhile to me, if you have the DIY skills.
 
If we're going off @rb2013s scale with the stock Breeze with GE power cord is 108 (98 without) and the stock U12 is 72, I'd place the Breeze with new clocks at 120-125 and, assuming the GE cable has the same effect as before (+10 points), you get a total score of 130-135. Maybe my numbers are inaccurate—there's a lot of interpolation off his scale, and I don't really understand what the numbers mean. But the point is that for $220, you can get an amazing DDC.

 

[abartels]

And yet another USB-Miracle shows-up on the horizon: http://ideonaudio.com/3r-usb.html

 

[prot]

And yet another USB-Miracle shows-up on the horizon: http://ideonaudio.com/3r-usb.html

Nice find. Looks like a (possibly) improved regen. Still no true galvanic iso afaics.

And btw did anyone try ifi's new filter? http://ifi-audio.com/portfolio-view/accessory-dcipurifier/. Any audible effects?
And are there some usb adapter connectors for it?

 

[auvgeek]

Nice find. Looks like a (possibly) improved regen. Still no true galvanic iso afaics.

Sorry if this is a stupid question, but can anyone explain (simply) the difficulty in designing a device with a reclocker (Regen, etc) AND galvanic isolation (Intona)?

 

[rb2013]

 
@bimmer100 modded my Breeze DU-U8, which I lent him partially so he could review it and we agreed that he should mod it while he had it there. It sounds SO good. The Crystek 957s seem to improved the soundstage and bass the most. The soundstage is obviously wider with a bit better imaging than before. That bass though! It seems to dig deeper with more punch (i.e., better dynamics) while still being tighter and more detailed than before. The highs are also clearer and more detailed, while still retaining the laid-back, non-fatiguing nature of the stock Breeze. Keep in mind my impressions are with the stock power cord, as my Graphene Extreme PC is currently being shipped back to me from my parent's house. But ~$100 for the clocks and dip14 sockets/boards seems definitely worthwhile to me, if you have the DIY skills.
 
If we're going off @rb2013s scale with the stock Breeze with GE power cord is 108 (98 without) and the stock U12 is 72, I'd place the Breeze with new clocks at 120-125 and, assuming the GE cable has the same effect as before (+10 points), you get a total score of 130-135. Maybe my numbers are inaccurate—there's a lot of interpolation off his scale, and I don't really understand what the numbers mean. But the point is that for $220, you can get an amazing DDC.

Great to hear the Breeze responded well to the better Cyrstek clocks.  It certainly is a great unit. 
 
The point rating is just a relative scale - 100 just being approx the stock Breeze with the Talema transformer.  I agree made significantly better by the Cerious Tech Graphene Extreme power cord (what happened to that guy?- he disappeared after I made him so popular.  Even had a audio reviewer contact me about reviewing his cables - as he could not reach him).
 
Anyway - this new class of USB DDCs based on the lastest XMOS 1000MIPS XU208 chip have just catapulted over the Breeze, Pro3a and the PUC 2 lite.
 
I would say the Singxer F-1 using Crystek CCHD 575 audio clocks, NDK SD clock for USB - is in a whole other league.  I just finished burnin at 200 hrs and would put it at 150-155.  With the improvements I have made in my data and ps chains - now the package at 170ish. It's that good.  The Singxer X-1 based on the 1000MIPS XU208 as well but with NDK SD audio and USB clocks at 140-145.  The F-1 is king right now - it uses very advanced FPGA USB isolation, multiple ultra low noise ADI LDO regulators, etc...
 
Here is the thread I started to track these amazing devices:
http://www.head-fi.org/t/803111/xmos-xu208-usb-bridges-the-latest-gen-has-arrived
 
Cheers!

 
 
PS There is much to go with USB and SPDIF as far as SQ improvements go.  Although I may have pushed the edge of the envelope as far as possible now. I use my old $30K analog system as a reference - this has surpassed it!  At a fraction of the total cost.
 
Three cheers for PC Audio!!!  And my old analog turntable could never have 3TB of music - 30 different playlists - mixing SACD, Redbook WAV, Digitalized LP's (at 32/176K), DVD-A's - all in one playlist!

 

[hgpsemaj]

Additional image of the diyinhk's Xmos XU216 2000MIPS PCB

 

[auvgeek]

 (what happened to that guy?- he disappeared after I made him so popular.  Even had a audio reviewer contact me about reviewing his cables - as he could not reach him).

According to the audiogon forums, he's just busy working 16 hour days and it takes him a while to respond to email.
 
I'd love to grab a pair of interconnects, but I can't afford retail and I seriously doubt he has any interest in selling them at a discount now that he's so popular. It'll probably have to be an "after grad school" purchase...

 

[rb2013]

  According to the audiogon forums, he's just busy working 16 hour days and it takes him a while to respond to email.
 
I'd love to grab a pair of interconnects, but I can't afford retail and I seriously doubt he has any interest in selling them at a discount now that he's so popular. It'll probably have to be an "after grad school" purchase...

I understand - but after buying three power cables from him and inquiring about the IC's he never answered my email!  That after generating incredible demand for his products by blogging about them.  Before I mentioned them - he was selling them at a 50% discount in Audiogon ads.
 
Not a way of saying thanks...

 

[auvgeek]

 
I understand - but after buying three power cables from him and inquiring about the IC's he never answered my email!  That after generating incredible demand for his products by blogging about them.  Before I mentioned them - he was selling them at a 50% discount in Audiogon ads.
 
Not a way of saying thanks...

 
He has interconnects for sale on Audiogon right now for quite cheap (nearly 1/2 off). 

 

[rb2013]

   
He has interconnects for sale on Audiogon right now for quite cheap (nearly 1/2 off). 

Didn't know - thanks!
 
PS Actually the digital cable look interesting...just sent an offer $199.
 
Let's see if he replies.  He may be mad at me - on the last order (my third) for the GE power cord - it was three weeks without hearing from him.  I mean not a word - then I sent two PMs, about three days apart - no reply.  The cable was fully paid for upfront of course.  Finally a week later he shipped it - never returning my message.
 
Great cables - lousy businessman.

 

[prot]

Sorry if this is a stupid question, but can anyone explain (simply) the difficulty in designing a device with a reclocker (Regen, etc) AND galvanic isolation (Intona)?

The hard part is the galvanic iso. Chips who can do that at full usb2.0 speed are rare, new and expensive. Afaik Intona has the only commercial chip right now .. few others are rumored to come.
And btw the intona device actually does both isolation and "regen". If you *really* need to clean your usb signal that is the device to buy right now.