Something cool for Raspberry Pi/ODROID: I2S/DSD isolator HAT with native DSD decoder

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#124
Hi, i am using Raspberry Pi 3 + Rune Audio to stream to External DAC with built in XMOS USB. Does it make sense to add a i2S Reclocker + Isolation with dual USB out and SPDIF out card supporting DSD signal? If yes, can you supply? Thanks
 
#125

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#132
Advice

Hi Ian,
I know that you are very busy but I would like to kindly ask your advice.
I have 2 dacs (Holo Spring & Gustard X20u) both with USB, Coaxial, Bnc AES/EBU & I2S (LVDS -HDMI CONNECTOR). Now I'm streaming music through HQ player on an IMac over Ethernet 2 NAA clients, a PI3+Hifiberry Digi+Pro (coaxial output) and an Odroid C2 (USB output). They are working well but I would like to improve them as much as possible.
I put an order for 1Pi/odroid isolator hat + DSD decoder to tested but since your boards are not available for purchase all the time I was thinking to go further and order all the boards necessary for the best configuration.
1st option: RPi3+ Or Odroid C2 -> RPi isolator+DSD decoder ->I2S hdmi-lvds adapter

2nd option: RPi3 or Odroid C2-> RPi isolator HAT -> FIFO + dual clock board -> I2S HDMI-LVDS adapter -> DAC I2S input

3rd option: same as 2nd but with your new multich FIFO & Clock boards.
Now my quetions are :
1. For the 2nd and 3rd option is the chain of boards correctly represented (I'm not so experienced so I'm not sure if Iunderstood properly each board usage)

2. Which is the best option for a mainly stereo ( at least at this moment) setup.

3. What cables are necessary to interconnect the boards for the best option (to be sure when ordering - not to end up with some cable/conector missing 🙂 ) or the boards ( fifi & clock) include also some cables.

4. Any rough timeframe for the respective boards availability.

5. How do you prefer, to update the current order (position 125 1x RPi isolator, 1xDSD decoder) in the Group Buy list or to create a new position with the additional boards / cables.

Thank you
 
#133
Hi Lucser, I'm using your option n.1 (Pi3 - hifiberry dac+ Pro as reclocker - I2s hdmi LVDS adapter), without Fifo and isolator. It works perfectly with my dac PS Audio Directstream, but using Gustard X20 Pro, 16 bit files don't work (24 bit is ok).

Ian, is there any chance to solve my problem with your boards?
 
#134
RPi Isolator with Allo Sparky

Ian,

I made a somewhat misguided purchase of an Allo Sparky SBC that does not work with the Boss DAC it was intended for. Do you know if your RPi Isolator and DSD decoder would work properly with the Sparky SBC? The Sparky was not that expensive, but would just collecting dust if not suitable for use (unless I could find another use for it or sell it). Thanks.
 
#136
Yatsushiro, thanks for the reply. It was touted as a superior SBC for music and the reason I chose it over a RPi. Didn't read the fine print(probably wasn't that fine) and did realize that it didn't work with the Boss DAC, also from Allo. I know it will work with a Kali and a Piano, but wanted to add the RPi Isolator and DSD Decoder in that Project (was looking at two systems) but I guess I could do three.
 
#137
lucser said:
Hi Ian,
I know that you are very busy but I would like to kindly ask your advice.
I have 2 dacs (Holo Spring & Gustard X20u) both with USB, Coaxial, Bnc AES/EBU & I2S (LVDS -HDMI CONNECTOR). Now I'm streaming music through HQ player on an IMac over Ethernet 2 NAA clients, a PI3+Hifiberry Digi+Pro (coaxial output) and an Odroid C2 (USB output). They are working well but I would like to improve them as much as possible.
I put an order for 1Pi/odroid isolator hat + DSD decoder to tested but since your boards are not available for purchase all the time I was thinking to go further and order all the boards necessary for the best configuration.
1st option: RPi3+ Or Odroid C2 -> RPi isolator+DSD decoder ->I2S hdmi-lvds adapter

2nd option: RPi3 or Odroid C2-> RPi isolator HAT -> FIFO + dual clock board -> I2S HDMI-LVDS adapter -> DAC I2S input

Hi

3rd option: same as 2nd but with your new multich FIFO & Clock boards.
Now my quetions are :
1. For the 2nd and 3rd option is the chain of boards correctly represented (I'm not so experienced so I'm not sure if Iunderstood properly each board usage)

2. Which is the best option for a mainly stereo ( at least at this moment) setup.

3. What cables are necessary to interconnect the boards for the best option (to be sure when ordering - not to end up with some cable/conector missing 🙂 ) or the boards ( fifi & clock) include also some cables.

4. Any rough timeframe for the respective boards availability.

5. How do you prefer, to update the current order (position 125 1x RPi isolator, 1xDSD decoder) in the Group Buy list or to create a new position with the additional boards / cables.

Thank you
Click to expand...

Hi,

Sorry for my late reply.

Production order was placed. They will be available very soon.

For now, I would suggest you going with option1. For better sound quality, you will need a FIFO and clock board for sure. I'm considering develop a FifoPi. I think that could be the right one you need.

Regards,
Ian
 
#138
Ian,

How about an isolated FifoPi that can optionally upsample to 384 in the FPGA?

That with some of the new Pi-DACs like the Allo.com Boss and the forthcoming Soekris Pi-DAC could be very very good with good power supplies!

Just wishing...

Greg in Mississippi
 
#139
IsolatorPi works with DAC HAT in Master Clock mode

IsolatorPi was tested working with HifiBerry DAC+ Pro in master clock mode.

In this configuration, both SCK and LRCK were generate from local XOs. RPi works in slave clock mode. DAC is driven by local clocks which have much less jitter than RPi generated clocks. RPi generates DATA signal only. RPi will not generate audio clock any more.

IsolatorPi works now in bi-direction mode. Clock signals will be fed back to RPi through isolator to synchronize the DATA signal.

Audio power supply is 100% isolated from RPi and RPi ground. HifiBerry sound better with isolator as I expected (I use 6V battery as audio power supply).

I2S and MCLK can also be tapped from the reserved SIP connector on DAC + Pro, like a Fifo.

It's a big step.


IsolatorPiMaster2 by Ian, on Flickr


IsolatorPiMaster1 by Ian, on Flickr


IsolatorPiMaster3 by Ian, on Flickr

Ian
 
#140
Ian,

Very cool and I bet it sounds very good. Especially since you aren't using the Pi's 3.3v to power the HFBD+P's PCM5122 digital side & the board's clocks like the unt does stock.

I have a HFBD+P I've modified the heck out of... some details on what I did for a page or so before and after this post:

http://www.diyaudio.com/forums/digi...ry-dac-pro-hw-mods-anybody-3.html#post4626613

And some additional details and pix here:

http://www.diyaudio.com/forums/vend...-here-bal-bal-se-se-lpuhp-18.html#post4626581

With three good power supplies feeding the R-Pi and the HFBD+P's 5v and 3.3v separately, it was sounding very good. THEN I tried the modified HFBD+P on an Allo.com Kali reclocker board in slave mode (where it gets the clock from the input feed) instead of master mode (where it feeds the clock to the Pi... and of course along with adding a 4th supply) and have preferred it that way ever since.

BUT I just got the new Allo.com Boss DAC going last night... Like the HFBD+P, it also uses the PCM5122 chip in master mode with 2 clocks to send to the Pi for master clock duties. I hear it sounds good that way too, but based on my experience with the HFBD+P, I first tried the Boss on a Kali reclocker board and 3 good power supplies, again 1 feeding the Pi, 1 the Kali, and the 3rd the Boss.

It only took a couple of minutes to hear that it was handily beating my modified HFBD+P... and it should, using better regs and power filter, along with a more sophisticated power bypassing network AND better spec'd NDK clocks (same as what Allo.com uses on the Kali).

I know you are super-busy, but you should get one of these to try on your isolator board... consider it a HFBD+P with the upgrades as above for only 1/3 more ($60 USD vs $45 USD for the HFBD+P)... and while I plan to further upgrade my HFBD+P to try and equal the Boss, I find my will to do so very low as the Boss is that much better with almost no work in my part!

Then others have reported better sound out of the PCM5122 by upsampling/filtering to 384 which causes a bypass of the PCM5122's built-in filters. With an LMS-server/SqueezeLite setup, you can do this either on the Pi (ok) or the LMS server computer (better).

John Swenson (designer of the Bottlehead DAC that uses the PCM5142 along with the Sonore Rendu Signature and MicroRendu AND the Uptone Audio Regen, JS-2, LPS-1, and now their forthcoming IsoRegen) started this idea here:

Upsampling Impressions

and Soundcheck has found it sufficiently beneficial with both the HFBD+P & the Allo Boss to write a blog post on how to do it here:

Raspberry PI - I2S-HATs @ 384k

All of that is why I asked for the feature-set in my post above... the isolator to provide the benefits you're already hearing, the reclocker to get what I heard going to the Kali with my HFBD+P (though with the Boss it MAY work better in Master mod, again I'll try that at some point), and the FPGA upsampling to get the best out of those (and many other) DAC chips.

Be that as it may, I am VERY excitedly awaiting your isolator hat!!!!!

Greg in Mississippi

P.S. I forgot you can find more info on the Boss DAC here:

http://www.diyaudio.com/forums/vendors-bazaar/300689-master-dac-boss-rpi.html

and here:

http://www.diyaudio.com/forums/digital-line-level/304004-my-new-boss-another-pi-hat.html
 
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