Raspberry Pi I2S to SPDIF Hat

Great news! My pi 3 will be here tomorrow .

 

Fantastic- fingers crossed that the new spin performs as it should!

Stupid question, but does this have any bearing on the progress of the digital-only 503SPD2 hat, on your "coming soon" page?

 

We dropped the 503SPD2 and as mentioned, combined the function of analog and digital into one product. We could not justify two boards.

This project was always a bit of a side project here. Something I wanted to do, but not our main focus. So I needed to make it work economically and get as much use out of the one board. Obviously I did not expect to mess up so badly!

Cheers,
Michael

 

Yeah, I was disinclined to read the whole 40 page thread, so it's useful to be brought up to speed, thanks.

That makes a lot of sense. I don't think it's a shocking compromise, as you seem set to price it sensibly. It's all about dem clocks, anyway, which are still there!

(..and some nice filtering)

 

Speaking of which, what would be the best approach for an lps: 5v into the pi usb connector through an adapter and let Michael's filtering do its thing or the regular smps to power the pi and use the external input on the hat? Ideally I'll move everything into an all-in-one box at some point to reduce clutter but for now an external like this one seems like a good compromise (assuming it doesn't catch fire and burn the house down) and I can cannibalize it for parts for the aio box later.

 

Pass, I don't have one of Michael's hats yet, and I'd not feel comfortable guessing.. sorry.

 

There is the possibility to split the power on the HAT, so you can feed both seperately. (remove a jumper). Power into the HAT /PI sound beter than's than PI/HAT.

 

Any clever ideas for battery powering the 502DAC? Could be interesting to have it as a low-noise + portable source, especially at such a low price point.

 

it's nice to see the digital output board is finally available to those who wanted it.. from a company brave enough.. to throw their HAT over the wall. yes I posted just to make that pun.

 

I was going to try a 12v lipo battery from eBay into a lm317 but never got around to it.

 

First off, Michael , thank you for the opportunity to test your design.

I will keep this very simple:

2 channel setup :
2 channel: Anthem MRX510 amp
12" DIY coaxials/
18" DIY subs

The comparison was done with a Pi2 (502HAT) and Pi3(Digi+) each running Picoreplayer 3.10 feeding optical to the amp. ( 2 identical optical cables).
HDMI switched off.
Both where fed from LT1083 linear PSU through the headers on the HATS.
Both were connected with LAN cable.
Daphile synced the 2 Pi’s so it was very fast to do A/B switching.

Music:
Nine Inch nails, Tori Amos, Ennico Morrison, Depeche Mode, Infected Mushroom, Nightwish, Burial, Children of Bodom, Leftfield,Johnny Cash, etc

502HAT
-Smoother and richer
-More present sub bass and bass-weight
-Much better sound stage, (depth, height and instrument placement) Width seems the same.
-More natural decay and bloom.

Hifiberry Digi+
- Drier, lighter sounding (transients seems more etched)
-Lack of body creates sense of speed
- Less sub bass, mid bass stronger
- Flatter and more compresses sound stage, especially height and depth.

Biggest difference between them is in the bass-presence and sound stage.

Difference as mentioned above was much more noticeable feeding them from normal SMPS via the Pi.
The 502HAT is much less sensitive to the PSU than the Digi+.

 

Nice review. Thank you.
But the real fight would be a 502DAC and a Hifiberry Digi+ pro, which also equipped with two clocks for audio signals. My bet is that Michael's 502DAC digital output still wins (better audio clocks, better onboard voltage regulator). Happy listening!

 

Sorry if this was covered before in the previous 40 pages, I missed it:
What outside diameter, inside pin diameter, and center pin polarity is required for the DC input connector that plugs directly into the HAT? I am starting to source parts for my build. Thanks!

 

Did you have the linear power supply feeding the pi or the 502?

 

Dual supplies: One linear supply feeding the Pi and a separate linear supply feeding the 502.

 

2.5mm center positive, 5.5mm length

Cheers,
Michael

 

Right now my new pi is running Kodi. Will I be able to use the 502 with Kodi?

 

As long as you can select the HifiBerry DAC+ Pro as the output device you are good to go.

Cheers,
Michael

 

Should be pretty straightforward. These ones are well reviewed and will charge themselves just like a phone when plugged in: https://www.amazon.com/s/ref=nb_sb_ss_rsis_1_11?url=search-alias=aps&field-keywords=anker+usb+battery&sprefix=anker+usb+b,aps,180

If in practice they isolate noise from the charging supply and you can just leave it plugged in all the time, that would make the idea of a discrete linear PSU kinda redundant as you'd have more than enough quiet power on tap.

I was planning on getting a Hifi2000 Galaxy 230mm chassis for my RPi source+PSU to match the width of my Bifrost. I played with the idea of chucking a battery in with a switch to go between PSU+battery charging or straight battery power. Dunno yet. Already have a couple AMB sigma11 boards on hand so I'll be starting with that.

 

I know I already managed a similar thing with my phone (OnePlus X) and a FiiO e10k using an external battery pack, and a y splitter cable (to get data from my phone, and power from the battery). OnePlus X is a noisy ass phone for audio stuff, and doesn't have enough usb power to push many external DAC/Amps. Could probably try to repeat something similar with a splitter cable for the RPi+PSU?