Opus DAC with Raspberry Pi Type B - diyAudio
Go Back   Home > Forums > Source & Line > Digital Line Level

Digital Line Level DACs, Digital Crossovers, Equalizers, etc.

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 18th March 2015, 07:17 AM   #1
kinku is offline kinku  United States
diyAudio Member
 
Join Date: Feb 2013
Default Opus DAC with Raspberry Pi Type B

Hi,
I am wondering if anyone has experience with using Raspberry pi Model B's I2S output feeding Twisted pear audio opus DAC ?
If anyone has experience with it please guide me.

Last edited by kinku; 19th March 2015 at 04:25 PM.
  Reply With Quote
Old 19th March 2015, 05:26 AM   #2
Dr Jim is online now Dr Jim  United States
diyAudio Member
 
Join Date: Jun 2011
I can't speak to how well the Raspberry Pi B will talk to a Twisted Pear Opus - but can say with some assurance that the I2S on the 'B' model seems to be quite clean and does not appear to throw off many of the artifacts that the original Pi suffered from.

Using both an original Pi and a Pi 'B' to drive a HiFiDigi I2S -> S/PDIF adapter feeding a PCM1794 OEM eval board driving a class A headphone amp into Fostex T20 modded phones I noted that passages which seemed congested and unclear through the Pi 'A' now played as I believe they were meant to be heard on the 'B.'

Specifically some of the moments in Mahler's 1st and 5th symphonies where the brasses blare out over the first & second strings now seem 'right' - the horns have body, and an almost 'silvery' note without being harsh, while the strings remain quite distinct both tonally and in their correct places.

There's no doubt that there is more CPU horsepower in the 'B,' there also seems to be better noise rejection, and far less cross-talk between the network and the I2S buses - with the net result that low-level passages emerge from a completely 'black' sonic background with out any sense of pre-echo, odd - almost dithered - background hiss, or an 'edge-of-hearing' ringing that the Pi 'A' would sometimes throw off.

For about $75 USD, the Pi 'B' + HiFiDigi board combo seems to be a surprisingly competent network music streamer - so the Pi B should drive the Opus DAC well if due care is used the transporting the I2S signal.

Cheers

Jim
  Reply With Quote
Old 19th March 2015, 01:07 PM   #3
kinku is offline kinku  United States
diyAudio Member
 
Join Date: Feb 2013
Thanks Jim. I have missed the digital age and don't know much about the i2s connections to DAC chips. Is there any cheat-sheets or articles that would explan the i2s connection between devices?
  Reply With Quote
Old 19th March 2015, 01:54 PM   #4
diyAudio Member
 
Join Date: Aug 2008
I think you might be mixing up Pi models. A and B were both original, B had ethernet and more RAM.

Model B 1.0: no I2S (not all the proper GPIO pins were broken out to headers)
Model B 2.0: I2S
Model B+ 1.0: More USB ports, micro SD, rounded corners
Pi 2 model B: Faster CPU, more RAM

Unfortunately, I have a B 1.0, so I can't hook mine up to a DAC
__________________
Tyler
  Reply With Quote
Old 19th March 2015, 04:25 PM   #5
kinku is offline kinku  United States
diyAudio Member
 
Join Date: Feb 2013
To be clear we are discussing on Pi Model B Revision 2.0 512MB
  Reply With Quote
Old 19th March 2015, 04:30 PM   #6
kinku is offline kinku  United States
diyAudio Member
 
Join Date: Feb 2013
AMB labs gamma 2 is also a strong candidate.Anyone did comparison with Oppus vs Gamma 2 in technical aspects. I am reading Twisted Pear site but don't think there are not many details for a novice like me.
  Reply With Quote
Old 19th March 2015, 07:22 PM   #7
glt is offline glt  United States
diyAudio Member
 
Join Date: Oct 2004
May not work with Opus as the dac chip needs a master clock and the RPi does not have an external master clock.

Don't know if the dac can lock to the bit clock
__________________
www.hifiduino.wordpress.com
  Reply With Quote
Old 19th March 2015, 07:26 PM   #8
kinku is offline kinku  United States
diyAudio Member
 
Join Date: Feb 2013
So how about AMB gamma 2? I guess it has a master clock on board. But trying to find out more about the over sampling to 96KHz . Is it going to down sample the 192kHz material?
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
DSP for the Raspberry Pi usul27 Digital Line Level 31 12th March 2015 08:31 AM
My DAC for the Raspberry Pi usul27 Digital Source 146 9th February 2015 07:22 PM
Raspberry Pi DAC options recommendations?? JonesySA Digital Line Level 8 9th December 2014 01:53 PM
miniAMP and raspberry pi kp93300 miniDSP 0 3rd March 2014 03:38 AM
Inexpensive DAC for Raspberry Pi streamer (Airport Express knockoff) hoffsta Digital Line Level 10 23rd June 2013 07:13 PM


New To Site? Need Help?

All times are GMT. The time now is 07:27 PM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2015 DragonByte Technologies Ltd.
Copyright 1999-2015 diyAudio

Content Relevant URLs by vBSEO 3.3.2