Raspberry Pi I2S to SPDIF Hat

Oh and it hates having that jumper removed. Then it can't synch at all. I don't have an opto cable with me. I am in the middle of a move and it is packed away and I live in a remote french village, there is no place to get one quickly. I will try the rca out.

 

OK good news is that the RCA outs work fine. It really could be that the StageDac is finicky...

 

Fantastic. Not to brag, but this is why I tried to insure a variety of connection options. It is still possible that my interfaces may not be 100% up to spec, or it may be that the world's equipment makers vary more than expected! Either way, it seems each of you guys has gotten at least one interface working and giving you sound quality up to par with or better than your current equipment. I totally want to hear from anyone for whom that is not true! And from anyone who has an interface that does not work right. This will helps us focus any improvements on those areas.

Cheers,
Michael

 

It is nice that the RCA out works, but the stagedac does sound a little better than the onboard DAC...

 

Yes, as it should. The PCM5122 is a nice DAC, but not on par with most stand alone DAC units. It was more of a sanity check for you. It's also nice to drive a power AMP instead of headphones. Speakers usually have enough distortion all on their own to mask the PCM5122 imperfections. IMHO!

Cheers,
Michael

 

Yes, I was planning on using the RCA outs for my humble desktop audioengine speakers. ANd the on board dac should be great for that. Actually, trying to buy a different DAC but in the general weirdness of life I have been blocked at every turn. Schiit couldn't make me a Gungnir Multibit even with a 6 week advance warning during me trip to the US. And they aren't available in Europe at all. It would be nice to get to the bottom of the stagedac issue. I will get an optical toslink cable in the next week or two. if i had a BNC/RCA connector with me I could try a different cable...

 

I am not sure, but if the 16/44.1k works via BNC with your corda stagedac, it seems to me that the pops caused by slow network performance (low data buffer settings etc). Do you run LMS on the piCorePlayer or on your computer? I found that 1) if I install and run LMS on the piCorePlayer and attache a USB hard drive to RasPi's USB, it will affect sound quality, which became a little edgy and less relaxed. 2) if I run LMS on a separate computer and connect with Pi via wifi, the wifi has to be very fast (strong signal, etc) to support 24/88.2k or above. Sometimes, reset and reboot wifi router could improve wifi transfer speed.

 

The built-in wifi isn't very good, there was a post I read somewhere that ranked various LAN connection types, this isn't it but close enough:



http://www.pidramble.com/wiki/benchmarks/networking

 

I always had problems streaming anything higher than 16/44.1k to RPIs from my NAS.
24/88.2k sometimes worked, sometimes had pops or occasional dropouts so basically it was unreliable.
PCM files with even higher resolution or any dsd files had dropouts every 3 seconds.
It might be the PI or the upload speed of the NAS or my crappy wi-fi, but I do tried with different routers. I gave up in the end and for the sake of my inner peace now I use a lan cable.

 

The onboard Wifi is basic, use ethernet.

 

Thanks for all the suggestions. I am using the wifi. But if that was the problem, why wouldn't it also suck with the built-in DAC on the board? Anyway, of course in the moving mess I can't find a second ethernet cable. Arrrg. Not a good long term solution because of the distance between my internet connection and my listening area.

 

Your dac may not have a transformer coupled spdif connection. I remember reading the digi+ pro had a jumper to disengage the spdif transformer for compatibility. On my dac, I could not find any info on my spdif but pictures showed a transformer so I stopped worrying about it so much. I found a pic from 6moons on your dac and can't see a transformer. This is pretty much beyond me. Maybe others can chime in. In know the transformers can reduce noise and since noise is your problem..........

 

The transformer can be on the emitter side, too. Either way.

The Rednet 3 doesn't have a transformer either for the SPDIF (the AES outputs are all transformer isolated). The signal ground is also chassis ground and tied to earth ground.

 

Please see my post #569 (sckramer) (you might have to scroll down)--> http://forums.slimdevices.com/showt...orePlayer-3-10&p=877554&viewfull=1#post877554

Wifi (pi3) for the hifiberry d+pro is it at times... bizarre. The 502DAC uses this same driver and XO clock frequencies.

I'd try wired ethernet as a test before anything else, to rule out wifi as the problem. Even with the pcm5122 working ok.

*** This is just a theory of mine re: wifi/hifiberry/pi3!

 

Thanks @Scott Kramer, those graphs you link to are interesting. I agree I need to try w/ethernet. I am using an odroid as a LMS server as well as a a networked drive server. Just can't find an extra damn cable! It's in a moving box and it's a pretty long drive to get a new one from where I live. But the view of the sea is unbelievable.

 

FWIW, I have an RPi2 and Digi+ with Picoreplayer connected through Ethernet to an (old, flatter) Apple Airport Extreme serving as a wireless bridge to another (newer, tower) AE which is connected through Ethernet to a Windows Home Server running LMS, and listening to 96/24 has never had an issue. The two AEs are probably bridged through their 5GHz channels.

 

I wonder if this method using a standard WiFi extender with LAN port would work as well.

Cheers,
Michael

 

I've been wondering the same thing. I have a Wifi extender at what will soon be my old house, and I am going back soon. So I might grab it and try it out, but it will be a couple of weeks before I can report back... I actually still think the problem is the StageDac. And FWIW, on redbook audio, the Pi2Design hat is obviously much better than going USB into the dac from either my computer or the pi, even with the IFI Nano stting in between.

 

@shabta

One interesting thing you can do with squeezelite* is set a network buffer / output buffer. By default it streams exactly how much it needs based on song file size.

Setting a large network buffer (say 800MB on a pi3, 400MB on a piZERO) effectively stops all network streaming during playback. Instead there's a large burst at the start of the song.

*** There's a trick you could test in your case with bad wifi or dropouts... *pause the song*. This will let the buffer fill, you can usually see wifi light calm down when done. Also might stop wifi interference/noise.


I set a large buffer this way on my main system (wired or wireless), to keep the pi doing as little as possible.


Here's settings for an example worst case I did... upsampled 384K serverside, sent as PCM to the pi, 700MB in 3 seconds -- although this is still useful with good ~60Mbps wireless and normal 44.1/16 rates:



See the server side network out, the network spikes are the song transfer. Normally there would be a continuous stream ~



I like to run my pi's this way! And maybe it'll help you debug, and keep this in mind for a really optimized setup.

*saw you are using piCore

 

Update on next batch and final revision.

We will ship the last ~35 units of the current revision (P3) in about 2 weeks.

The final revision (P4) has gone to the PCB fabricator. We removed the HP amp and added a 2-pin wire terminal connector. This is in parallel with the barrel jack and makes it easier to add external 5V when you have only wire ends.

See the final data sheet and user manual:

http://www.pi2design.com/uploads/4/8/5/3/48531975/visio-502dac_datasheet_p4.pdf
http://www.pi2design.com/uploads/4/8/5/3/48531975/502dac_hw_ref_manual_p4_0.pdf

Cheers,
Michael