Bruce Rozenblit
This little project uses the Raspberry Pi 4 as a true high end music server.  I couldn't believe how good it sounds.  It's not a kit, but a simple DIY project. 
When I rediscovered vinyl a few years ago, I couldn't listen to my digital files any longer.  They sounded dead and lifeless.  Now I can enjoy them again.  This is a huge improvement and you can build it for less than $150.

https://www.transcendentsound.com/pi-music-server.html
Quote 0 0
Deleting Attachment...
I’ve been looking into these... I’d be tempted to get the option with digital/SPDIF output, galvanic isolation and reclocking (Digi+ PRO) and hooking that up to a high quality DAC of your choice.
Quote 0 0
interesting and to pursue. Thought. i would imagine there is NO INTERFACE into a vacuum tube preamp? any thoughts, thank you all
Quote 0 0
I had this exact same setup but with RPi3.  I think i paid about $90 total.  The hifiberry DAC + uses a Burr-Brown chip.  This is an incredible budget build for an audiophile.  I have a 500GB SSD with all my music on it.  Volumio is the best OS i could find for music on an RPi. There is a free option and a paid option where streaming services are native to the program.  i found that you could actually log into a streaming service and Airplay through the RPi, this kinda sidesteps the paid version.  For digital out you will want the HifiberryDigi+.  Here you could have something similar to a Bluesound Node or Vault 2i.  This would be great if you already have a high quality DAC.    
Quote 0 0
Peter,

The hifiberry DAC+ has RCA outputs.  I believe the output V is somewhere around 2.5V.  You can absolutely run this to any preamp.  
Quote 0 0
Eric C.
The HiFiBerry DAC + Pro Bruce mentioned, is a DAC that has RCA analog output. You connect them to your preamp via interconnect RCA cables.

peter romano wrote:
interesting and to pursue. Thought. i would imagine there is NO INTERFACE into a vacuum tube preamp? any thoughts, thank you all
Quote 0 0
Bruce Rozenblit
HiFiBerry has a USB I2S interface board also that uses their top hat boards and is fully USB powered.  It's in beta test.  I have one.  It sounds marvelous, but it needs to be driven by a computer.  This would function as a stand alone USB DAC.  I went with the Pi so I could get rid of the computer and run the whole thing with my iPad.  Either way, these guys are going to put the high dollar DAC companies out of business.  I just don't see any reason to spend more money.  With the top hat configuration, if a new DAC chip ever comes out, just pop on a new board and you are up to date. 

With the new hi res streaming services, music is completely changing for us.  Amazon is starting a service that is only $13/month if you have Prime.  If Volumio comes up with a plug-in for that, then you can have their entire library at least with 44.1 Khz-16 bit quality, and 24 bit-192kHz is being added all the time.  All you need is a great tube amp and preamp and you are set to go!  I can help with that!   
Quote 0 0
Been using this setup on a Pi 3b with a grounded grid and evermore for a year or so. Sounds great and easy to setup and use.
Quote 0 0
Thanks, Bruce

This is really timely for me.

I've been considering a pi for some time as a nice compact low power media pc to replace my htpc build (mainly because of size and noise issues with HDMI - assuming from the PC PSU).  The pi can be run from a lithium battery pack and hopefully would eliminate that noise on the ground from the PSU.

I already have a DAC (or 3) and an AV processor, so I'm looking into HDMI MCH output... it seems possible from various posts.  If I can get low noise MCH over HDMI and HD stereo from USB to DAC, I'll be all set.

For those of you interested in the HiFiBerry, here is some objective confirmation of its quality:
https://www.audiosciencereview.com/forum/index.php?threads/review-and-measurements-of-hifiberry-dac-pro.8555/

For the Canadians out there, kits are available at very good prices from CanaKit.  Here's the top of the line model:
https://www.canakit.com/raspberry-pi-4-complete-starter-kit-official-case.html
I think the official case is hideous, but to each their own.

If you need more horsepower for DSP and other duties, check out Archimago's blog for a big server/pi renderer configuration (many posts on the blog):
http://archimago.blogspot.com/

Looking forward to hearing about your experiences.
Phil

Quote 0 0
Carson
Just adding some possibilities...I’ve been using a RPi for quite awhile and find this company pushes the envelope with some really neat products.

https://allo.com/index.html

I currently power a DigiOne (old one not signature) RPi with a battery pack (2A output) into a DAC and it sounds as good as a full blown Mac Mini with Audirvana. Hard to believe people convert Mini’s to 12 vdc (LPS) and change to linear fan control...to “improve” transport of files... I haven’t jumped that far in.

https://www.runeaudio.com/forum/pecanpi-next-generation-raspberry-pi-dac-and-streamer-t6765.html

This HAT looks really high quality, price is high too...I haven’t figured out what Rune brings to the table either.

Best sounding digital music I’ve ever heard is a DIY Soekris DAM1021, with Borbely shunt reg. PS, raw output to a Wolfgang EF86 buffer (as discussed in the R-2R thread) feeding my dual mono CFA; studio albums never sounded so alive.

Quote 0 0
Post script

Older RPi 3 don’t require a fan. The 4’s apparently run hotter. RPi 2’s don’t have WiFi...If that kind of thing bothers you; just need to connect Ethernet cable.
Quote 0 0
Suggest you look into Moode Audio as well as Volumio.  I find that Moode sounds better and is a bit more powerful all the way around as Volumio.  I've got 5 of these little devices scattered around my house and shop and I love them.   I've tried most of the DAC hats and found that a good power supply plus Allo products have given me the most bang for my buck.
Quote 0 0
Can I use a HifiBerry DAC + DSP?
Quote 0 0
> Can I use a HifiBerry DAC + DSP?

Yes.  DSP is applied before sending the audio to the DAC (e.g. by JRiver.) It all depends on the CPU power and buffering.  You might have trouble with some HD files or streams, and have to convert to a lower sampling frequency.
My i5 8th generation PC with DSP convolution turned on handles PCM up to 24/192k but stutters when trying to convert that PCM to DSDx2.  (Who cares? PCM and regular DSD are fine.)  I think the pi's ARM processor is a bit slower.

Others in the forum might have pi/DSP experience and be able to advise you more precisely on the limits.  But the pi 4 is a lot more powerful than even the pi 3.

Quote 0 0
Bruce Rozenblit
Jon,

Thanks for the tip on Moode Audio. I will flash an SD card and try it out.
That's one of the great advantages of using the Pi as a foundation for a server.  All you have to do is get another SD card, flash it and boom, you have a different system.  If I like it, I'll list in on the web page.  The flexibility here is enormous. 

I don't see any need for power supply hacking.  The DAC board has its own regulators which take any noise out.  There is no perceivable noise on the output.  Once you get the noise floor 100 dB below the signal, further reductions do not matter.

This is fun.  We can play and mod our systems for very little money.  This thing costs less than many people will spend on just one capacitor.   
Quote 0 0
Deleting Attachment...