Sync Multiple Tone Boards

I would like to use 2 tone boards - one to drive the main speakers (via Hypex Amp Modules) and one to drive powered subwoofers. From research so far I think that, if I use USB inputs on the tone boards, the outputs are not likely to stay in sync.

Can more than 1 tone board be connected to a VIM and, if so, would the outputs of the tone boards stay in sync?

Alternatively, if I use something like a miniDSP nanoDigi (this has 4 SPDIF outputs) to drive the tone boards (using the SPDIF input on each tone board) will the tone boards stay in sync?

Or, is there a better way of doing this than either of the above?

maybe send same i2s signal to both TB ?

Interesting idea.

Can 2 tone boards be connected to one VIM and, if so, how would the VIM need to be configured so that both tone boards could be seen by software?


the software on the vim has no clue on what happens on one or many tb: the OS just sends some audio stream over i2s , which is monodirectionnal stream in fire and forget mode

Yep, it’s possiable. And the VIM3/L supports up to 8 channels I2S in case you want different TB roles as multi-channel output(might not make too much sense for Hi-Fi application).

Yes in this case if the inputs from miniDSP stay in sync.

Solution using VIM3/L sounds interesting because I would want different TB roles - one TB to drive main speakers (via Hypex amp modules) and the other TB to drive 2 powered subwoofers.

Ideally I want something that Roon software would recognise as a multichannel DAC. I would need to connect the VIM to MacMini (by HDMI or USB?) so would need to run software on VIM which enablesd the two TB to look like a 4 channel DAC. Any suggestions?

Wonder why still need a MacMini, as the VIM3/L is a computer & player, and you can run Roon software on VIM3/L.

But be note that the default connection between the VIM serial SBC and TB via USB and almost all of OS we develped support the TB. Regarding the I2S setup, need built a new image to support that.

So looks like I would need VIM3/L with M2X and 2 TB connected via USB. Would Roon recognise that as a multi-channel DAC? Would the TBs remain in sync when connected by USB?

Alternatively, could I use Edge + Captain and connect the TB using the two FPC connectors on the Edge? Would that be any better in terms of ensuring that the TBs stay in sync?

I need do further discussion with our team first then respond back to you.

Thanks. Much appreciated. Look forward to hearing more …

i also would like khadas to propose a solution for pure stereo, active digital crossover, ability to run dsp algorythms on the sound card itself, and of course, use ess sabre dacs on all outputs (8)


Can TB be used as a hat (or maybe more than one) on RPi? or be used off board i2s in RPi? maybe with OS like

i think rpi hat = no because dfferent 40pin layout compared to rpi , unless using a specific adapter you are able to build

we d beter try to port roopiee or anther roonendpoint app to vim, maybe some roon endpoint is already avail in the kodi based distros like corelec and librelec !?

@Gouwa Any news on this?

if u need use two or more usb audio devices as one multi-channel device (its same for any soundcards same as tone board not only for usb )

u must check this one simple way
Virtual multi channel devices this one is common alsa API from libalsa

read more about this there ->

this method can get easy result without any manipulation just write proper config file for alsa

Wellcome if u need more assist

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Thanks for the feedback. Had a look at the link. Unfortunately it says:

“If you would like to link two or more ALSA devices together so that you have a virtual multi channel device it is possible. However this will not create the mythical “multi-channel soundcard out of el-cheapo consumer cards”. The real devices will drift out of sync over time.”

It’s the drifting out of sync that I am trying to find a solution to. Any suggestions?

why not ! u can try ! i think its enough for common users :wink: (for example i cant hear differents at all )

if u really need multichannel hi-end output plz ready to pay about 1K for midrange profesional audio interfaces like this and u can forget about some problems :wink:

@mike247 you’ll need multichannel soundcard for what ? 7.1 homecinema ?

Crossover using 2 main speakers and 2 subwoofers - so need 4 channels minimum.