Go Back   Home > Forums > > >

miniDSP Low cost, modular Digital Signal Processor (DSP) kits for the DIYer from miniDSP.

Reply
 
Thread Tools
Old 2nd April 2021, 10:38 PM   #1
redger is offline redger  Australia
diyAudio Member
 
Join Date: May 2008
Default MCHStreamer / USBStreamer - How To Split & Send I2S Via 5*SPDIF Coax

I see that the MCHStreamer and USB Streamer support 10 channels in via USB and 8 channels out via I2S plus another 2 via existing SPDIF - for a total of 10

I'd like to somehow take the 8 I2S channel outputs, convert them to SPDIF and send them along to 4 Khadas ToneBoards ... to support active speakers (DSP functions applied in the source PC) with mostly 44k & 48k signals ie. CD and Video standard audio

In theory its easy. ToneBoards accept I2S input (in theory) and I2S can be converted to SPDIF
BUT

How to do this,
  • sending over distance > 25cm (my understanding is that signal I2S integrity suffers over these distances)
  • sharing one clock from I2S so all DACs are synchronised
  • sending "correct" voltages etc
  • I'd prefer to avoid debuging I2S - I2S unless both ends are known to be compatible across all proposed use cases

Is there an add-on board that will plug-n-play. Does anyone have schematics or advice on how to do this (or how not to do it)?

I'm aware that the UDIO-8 and nanoDigi offer this kind of functionality but both are limited to 8 channels out and the nanoDigi only offers 2 channels in

grateful for any advice
  Reply With Quote
Old 2nd April 2021, 11:24 PM   #2
CharlieLaub is offline CharlieLaub  United States
diyAudio Member
 
Join Date: Mar 2007
Location: Michigan
What exactly are you trying to achieve?

Instead of doing DSP at the source, you can do it in the mini-PCs at the speakers. You use a single mini-PC (ARM, etc,) plus a single, multichannel audio interface, one per speaker. If you are interested in digital input, there are pro audio interfaces with SPDIF inputs. For example, the Behringer UMC1820 will give you SPDIF in and 8 analog balanced output channels and 2 digital output channels. You would have to run the processing chain from input to output at the SPDIF rate, and know what that is in advance.
__________________
Visit my Audio Web Page <<--CLICK TO LEARN MORE-->> Get my LADSPA plugins
  Reply With Quote
Old 3rd April 2021, 12:02 AM   #3
redger is offline redger  Australia
diyAudio Member
 
Join Date: May 2008
Quote:
Originally Posted by CharlieLaub View Post
What exactly are you trying to achieve?

Instead of doing DSP at the source, you can do it in the mini-PCs at the speakers. You use a single mini-PC (ARM, etc,) plus a single, multichannel audio interface, one per speaker. If you are interested in digital input, there are pro audio interfaces with SPDIF inputs. For example, the Behringer UMC1820 will give you SPDIF in and 8 analog balanced output channels and 2 digital output channels. You would have to run the processing chain from input to output at the SPDIF rate, and know what that is in advance.
Thanks for the response

In an ideal world I would use a single SOC style PC (mostly I use S9xx boxes running CoreElec) which starts with 2-8 channel audio which is then adjusted by Kodi into 2-5 PCM streams
I want to allow for -
  • 2 * 3 way Front Main speakers = 6 Channels
  • 1 * 2 driver Centre speaker = 2 channels
  • 2 * 1 "input" rear speakers = 2 channels

So in an ideal world I would have taken my 2-8 "speaker" input from the source material, mixed it "down" to 5 "speakers" in Kodi and then split each of the 3 main channels + the Centre channel using CammillaDSP to obtain a total of 10 channels. A bit of Alsa (and possibly Pulse or PipeWire) trickery is required

In the end I see a benefit to active crossovers on main speakers ... but surround not so much.

The nanoDigi won't fit because it's only 2 channel input
The UDIO-8 "could fit" but a bit limiting since 3 driver Main Left & Right consume 6 of the 8 leaving only 2 for "others"

The best alternate I could find was a Motu Ultralite MkIV but it "may" be unreliable on linux and has a"good" but not "great" DAC (ES9016) with no option to improve that ... and its expensive for those of us in the antipodes It does offer USB input and 8 analog output + 2 SPDIF out (according to documentation) ... which actually looks a lot like the MiniDSP Streamer series devices and appears to be a functional fit

From tests on AudioScienceReview the MiniDSP gear looks like good concepts with so-so engineering / production so I'd rather avoid using such products to manipulate the signal if I can. And PCs should have plenty of processing power for this application (in fact my S922x is ridiculously overpowered for its current tasks)

So then I was looking at the MChStreamer ... and thinking to self it may well be used by Octo8 and Motu as an easy building block ... I wonder how they do it. DIYinHK also sell an Xmos 200 unit with USB in and 8 channel out but that looks even more technically risky (I2S seems like a bit of a non-standard with many traps for the uninitiated / unwary)

Last edited by redger; 3rd April 2021 at 12:30 AM.
  Reply to this post

Reply


MCHStreamer / USBStreamer - How To Split &amp; Send I2S Via 5*SPDIF CoaxHide this!Advertise here!
Thread Tools

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

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Send Cut Send - laser cutting astouffer Tubes / Valves 47 6th March 2021 10:28 PM
MCHSTREAMER and J.River CROSSOVER Tesla Audio Equipment & Tools 0 6th March 2020 08:15 AM
Usbstreamer problem with BIII/BII in I2S Microfast Twisted Pear 26 21st April 2018 02:13 PM
USBStreamer and 192kHz SPDIF sync??? HpW miniDSP 6 12th November 2014 05:33 PM
If you use the SPDIF/coax output of your DAC, and plug into the SPDIF/coax input of ag8908 Digital Line Level 6 27th March 2014 11:11 PM


New To Site? Need Help?

All times are GMT. The time now is 09:21 PM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2021 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 15.00%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2021 DragonByte Technologies Ltd.
Copyright ©1999-2021 diyAudio
Wiki