Raspberry Pi I2S to SPDIF Hat

Hello Haywood, I want to buy the power supply you mentioned 'S23 KG Edition 30VA'; i plan to use it the same way you said, power both the pi and the dac from the DC jack.
Can you tell us some impresions of this LPS vs some usual switching power supply, phone charger etc. It's true it improves only the analouge out of the 502DAc not the digital out?

thank you!

 

Sorry, yes, I meant W1 (I need to edit my original post), which is labeled "PI 5V". I have installed a standard jumper and verified that the pins are shorted with 0.01R between the pins.

Good suggestions! I don't have a suitable cable (Banana jacks to microUSB) to try to power the Pi3 from the power supply (GW Instek PC-3030D). The 502DAC seems happy to be powered from the Pi3 using an "official" 5V @ 1A switching wall wart since it plays the stereo test just fine. So, it appears there is something wrong in the path from the 502DAC to the Pi3.

I will probe pins 2 and 5 to see if I get about 5V on each and report back.

 

Do not spend too much time on it. We can send you a new unit early next week. We have more stock coming in tomorrow. Since yours is a beta unit anyway, it's good for us to upgrade you.

Send me an email to:
[email protected]

Cheers,
Michael

 

If you've browsed eBay you know that several people are selling very similar devices. This one is a Chinese clone of a well-regarded DIY lpsu and is well put together with clean solder joints, wiring, etc. It runs relatively cool and is silent. The seller was responsive to questions (you specify the configuration you want and they custom build it) and shipping speed wasn't too bad. It's not UL or CE listed though and I have heard of people having trouble with customs.

As for sound there is no analog on the test boards but I thought it improved the digital section compared to the different switching power supplies I had used. It's not a huge difference as the 502DAC has a quite good power regulator but I thought it added an ease to the sound when powering both the Pi and hat via the DC jack.

I think the iFi switching supplies are probably better for most people for this application though, they're certified, run cooler, consume less electricity, are much smaller, about half the price and tested better in a shootout (posted earlier in the thread) than many of the lpsus you see on eBay.

 

Photobuckets blocked the pictures in my posts. sigh ...

 

http://imgur.com

 

Hi @Michael Kelly

I'm very interested in the 502DAC and I just joined the forum and started reading from around page 40 of this thread (that seems to be where all the actions starts!).

I THINK I'm up to speed on everything.

Just some really silly questions (apologies in advance)

1. To power the 502DAC board and Pi3 board's separately, how do you actually remove the jumper? Are any tools required?

2. If using only one digital output, is the linear regulator powering all outputs and the DAC at the same time, even if nothing is plugged into those outputs? Or is power only supplied to that one digital output that's being used?

3. What do the 3 LED colors correspond to?

4. Was there any update on accessing the SD card slot through the case with fingers (no tweezers) or are you still waiting to find out? Or is using tweezers going to be the only way? I currently have a HiFiBerry Digi+ Pro in their official steel case and can easily access the card, even with my fat fingers!

Appreciate your help

 

1. The jumper is a standard, old school 2-pin jumper that is similar to those found on ATA/PATA (not SATA) hard drives. Just pull it off.
2. I would guess they are all powered at the same time as I can see the TOSLINK output glow (kinda neat). They are all low current so applying voltage to them should not affect the available power. FYI, playing music through the BNC (not using the DAC), the 502DAC uses <60 mA (0.06 A). I could hook up a more precise meter and see, but that is tiny. Compare to the Pi3, which uses about 600 mA when chugging through something.
3. See Hardware Reference manual at: http://www.pi2design.com/store/p15/502DAC_-_Pro_Audio_Shield.html. I guess p3 is the one I have and p4 is the new board. Bottom is power, middle one is 44.1 KHz, and top is 48 KHz
4. Sorry, but nothing newer has been posted if you read back a page or 3.

 

Thanks Xen! I guess if there's any info that needs updating Michael will jump in.
Thanks again !

PS: @Michael Kelly I would be happy to pay $20 more for a pair of Crystek 575's: https://www.computeraudiophile.com/forums/topic/31572-superclocks/?do=findComment&comment=654629

Have you given more thought about a higher spec'ed Cyrstek version?

 

The 502AES will allow for external clocks. That is currently the only plan for crystals other than the NDK. Sorry.

Cheers,
Michael

 

Thanks for the info Michael.

 

Hi @Michael Kelly

Which of these adapters is compatible with the balanced 1/4" inch output of the 502DAC:

http://www.neutrik.com/en/accessories/circular-adapters/na2mp

http://www.neutrik.com/en/accessories/circular-adapters/na3mp

Cheers

 

NA3MP.

You can get a cable (TRS to XLR cable using one of their AES cable choices) instead of an adaptor from places like BlueJeans/Redco too.

 

True, I'll probably also end up getting the 502AES later, so i might as well order two cables from BJC now instead of getting hit with shipping twice - one TRS-XLR and one XLR-XLR

@Michael Kelly are there plans to add a digital isolator on the 502AES board? The new Allo DigiOne uses an isolator from Silabs I read

 

You only need the one cable, XLR Male to XLR (whatever your end need is). We supply a 1/4" to XLR Male adapter with the 502DAC.

As for the AES, we use SiLabs isolation on the external clock inputs. The BNC and XLR are already isolated on all the boards. The I2S over HDMI (using LVDS signaling) is not isolated.

Cheers,
Michael

 

Thanks for the info Mike.

 

Hmm. What are the jitter specs of the isolators?
Using them on the external clocks input might defeat the purpose

 

Dumb question: How can I edit my previous post to change the links of images? I could not find the "edit" button for my previous post. Thanks.

 

Should be at the bottom of your post, near your name and the date/time stamp of the post.

 

Yeah, I saw that on my post above as long as I logged in, but that "edit" was gone on my older posts. I only see "Report". I guess after certain time older posts from lower level (newer) members get locked?