Raspberry Pi I2S to SPDIF Hat

As a follow up to my previous post about THD using the Pi and Digi+, another member on the RuneAudio forum performed the test and got much different results. #3 is the Digi+ coaxial and #4 is the optical. I am beginning to feel a little better, though I still dont understand why the Pi and Digi+ seem to emphasize the mid and mid bass more (or is it my PC is leaning out the sound more???).

 

Pi 2 Design 503DAC1 is on it's way to you! I know you can test the digital side, but what about analog? And who did the Digi+ testing your showing? W have an R&S analyzer, but it does not have digital input. I'd be curious if we could get that person involved in the SPD1 and SPD2 testing. BTW, PCB's for those showed up today and we'll be building protos next week.

Cheers,
Michael

 

Thank you Michael. I am really looking forward to it. I can test analog too. My integrated amp accept RCA so I can at least let everyone here know how the DAC sounds compared to my Luxman. I will check with the poster on the Rune forum to see if they are up for testing the SPD1 and 2.

Great news on the PCBs. Man you are sticking to your original schedule! Very impressed.

 

Hi tboooe, did you try direct with the digi+? I think the goal should be near perfect spdif-- so a reclocker should not be needed or would make it worse... also might mess with your listening comparisons to the D1/D2.

 

Hi Michael,

I'd be very interested in testing your prototype D1 & D2.

My plan would be to compare with various configurations:


USB Switching Power - piZERO - digi+ (stock, how most people use it)

LT3042 LPS x3 - piZERO - digi+ (my setup: BNC, TOSlink removed. LPS 3.3V to the WM8804 (decoupled from pi), LPS 5V pi, LPS 5V wifi)

--to--

USB Switching Power - piZERO - D1/D2

USB Switching Power - piZERO - D1/D2 (5V LPS)

LT3042 LPS x3 - piZERO - D1/D2 (5V LPS, LPS 5V pi, LPS 5V wifi)


Testing only with piCorePlayer software.

Thanks!
Scott

 

Scott, question from a noob....doesnt the Pi and Digi+ have jitter that can be improved upon with the Mutec? Not sure if anyone has measured this.

i will try SPDIF direct to my DAC right now.

EDIT - I just tried connecting the Digi+ directly to my DAC and the sound characteristiics as I described before remained the same. Everything through the Digi+ just sounds more congested, less extended and a bit bloated to me. To my ears, the Digi+ sounds like a poorly made tube preamp with a very warm, slow, syrupy sound with almost a boominess to the low end. My PC through the Mutec on the other hand, sounds extended and the soundstage envelopes more of the room while music directly from the Digi+ feels like its confined to a smaller space between my speakers. Bass through my PC is also tighter.

Note that I am not saying the Digi+ sounds terrible. It does in fact sound good but for whatever reason, its sound is colored and not very engaging, ideal of casual listening or background music.

 

I'll add you to the list. BTW, we have a pi-Zero sized DAC, 504DAC1. Maybe I'll pop one over to you now if you're interested. Almost the same as the 503DAC1 I sent to tbooe and vastx. Send me your contact info and address to [email protected] if yo're interested.

Cheers,
Michael

 

Very interesting impressions. Given all the hype about how great the pi and a spdif hat could sound with the right power, etc. I was actually expecting a closer race. Your impressions sound like what I get out of a tweaked pc running foobar with no bridge , straight usb dac. although in that use case , it is way better than background or casual listeningj, just not as good as the Mac Mini setup.

I suppose your experience with higher end setups puts overall relative SQ with these budget devices a bit further down line on an absolute scale, instead of the more often reported "good for the money" scale.

It is exactly these type impressions from members who have listened and tried various setups that makes this forum so valuable. I'll be waiting for more reports on the overall level of SQ attained with these and the forthcoming new devices. For now I guess I will not be running to ebay to sell the Win laptop just yet.

 

I apologize, but I just realized that my Pi3 and Digi+ was being fed 5V from a cheap wall wart power supply. I must have switched from my linear power supply a while back and forgot. My Pi3 is tucked away at the bottom of my rack so its hard to see where all the cables go. LOL! I just tried powering my Pi3 and Digi+ with 5V from my HD linear power supply and I must say the sound has gotten closer to my fully tweaked PC. I need to spend more time listening but the syrupy, thick sound seems to be gone though it still sounds like my PC does something better to make the music sound more organic. I will report back after I listen some more.

I think a more fair comparison would be for me to use an UP Board and install all of my software optimizations that I have on my tweaked PC. That way, the only difference would be between hardware. Luckily, it sounds like the SPD will work with Pi and UP.

 

Are you still powering it through the Pi?

 

I am. I was going to supply 5v direct to the Digi+ but have decided to wait until I get the SPD protos before doing any mods. Plus I am lazy.

 

Just wondering as it does make a difference. Ask Scott, that is where I got the idea from. Looking forward to hearing about the new boards.

 

What will be really interesting is when I try HQPlayer and use the Pi3 or UP Board and SPD as the NAA. I am going to load up HQP on an ultra portable i3 laptop I have and compare that to my tweaked pc.

 

Sounds cool.

 

yes, that should be interesting. I run my HP setup on a i5 lappy but feel a desktop would probably sound better. Something about the screens in them. Big change going from a macbook to mini back in the day.

 

Man of little faith!

Man, stop spreading the panic!

Anyway... I can't help thinking that no matter things came back to normal and you can appreciate again the PI\digi+ sound quality with the right psu there's something we gotta consider here. I'm talking about system synergy. I don't know your dac personally but I heard from people that had it that it is on the warm\syrupy side of sound. Thus you are likely to appreciate more a lean sounding transport.
I'm not implying that your system sonds bad in any way, only that it could be somehow flavored on the warm side.
For this reason I advised you to try the chinese digipi which is leaner than the digi+, and for this reason I didn't like it much. It costs only 25 Euro here, not an expensive trial.

 

I think I will try the cheaper digipi, as my system is currently warmer than I like and its cheaper to keep the Gungnir Multibit than buying an Yggdrasil. I'll post how it stands. Its not screechy though, is it?

I am also comparing the Gungnir Multibit fed by a good (it should be) spinner/CD player against the CD output and they are close, in spite of the fact that they are using the Schiit Pyst with the Gungnir Multibit and an Audioquest XLR to the preamp. You can still tell them apart,but its close enough.

Keep batting away at the power supply, @Vastx . I know the DIGI+ sounds a lot better with a lithium ion battery feeding it, so a cost effective LPS should be worth it.

 

Hi Michael,

Why do you want to test these? Are they related to the D1/D2 designs? There's a DAC and WM8804 on it...??

I work with the HifiBerry D+Pro, but this is a different Dac chip...

Something better with the power layout?

 

Sounds good, Thanks!

Would like to focus on the SPDIF boards... not sure why these Dacs are in the mix?

 

I received that 503DAC1 that Mike sent for me to test. Let me say that even though I will admit I love music and spend a lot of money on my gear, I am not the best tester. This is because I dont get too caught up in details and minutiae. If I dont hear a difference or improvement in the first 1-5 mins of listening or if I am not immediately impressed, I move on. If I do like what I hear then I will listen more closely to try and figure out what are the pros and cons of what I am hearing.

That being said, the 503DAC1 is very impressive! I have only tried the SPDIF output as I want to compare it the Digi+. First of all, the 503 worked perfectly with my RuneAudio beta image running on my Pi3. Getting it to work was a easy as pluggin it into the Pi3. As for sound I was immediately struck by how much more detail I could here, especially in the mid range. That warm, syrupy sound I was getting from the Digi+ is mostly gone though I still sense a bit of over emphasis in the lower frequencies. This could be because of the differences in SPDIF cable compared to my Lightspeed USB or the SPDIF versus USB input of my Mutec 3+. The sound however, is clear and very engaging. I've spent an hour or so with the 503 so I need to listen to more music. However, from what I have heard so far I am VERY optimistic about the upcoming SPD products and the possibility of it sounding at least as good as my fully tweaked out PC. ! We are all in for a treat for sure!