miniDigital Spdif/Toslink + SRC I/O card

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While manufacturing is about to come to a complete grind in China for the next 2.5 weeks (Chinese New Year Celebrations oblige), the miniDSP Dev Team thought it would be neat to give you a sneak Peek at what the new miniDIGI I/O card looks like. Few lucky beta testers already enjoying its benefits as we speak... :)

2 x SPDIF inputs, transformer isolated
2 x Toslink inputs
While only one input can be selected at a time, the multiple inputs are meant to be used as a source switching device for your digital sources with a simple header. (could be replaced by a 4 pole switch)

The selected signal then feeds a sample rate converter for de-jittering of the signal and allowing a wide range of inputs. (up to 216kHz).

1 x SPDIF, transformer isolated + 1 Toslink outputs (signal duplicated to both outputs) then takes care of the processed I2S signal from your miniDSP kit (or any other DIY board as a matter of fact). Stack it up on top of your miniDSP kit and off you go for an all digital miniDSP kit bypassing the on-board ADC and/or DAC.

Finally, with its flexible expansion headers, this board doesn't limit itself to the miniDSP series. One can easily use this board for its existing system, providing a SPDIF/Toslink -> SRC -> I2S conversion or I2S - > Toslink+SPDIF conversion. Be creative!

More to follow very soon with the preliminary spec sheet on our website.

Expected shipping date when SMT factories get back to work in 3 weeks from now or so... Release early march sounds about right.

Stay tuned!

miniDSP DevTeam
 

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Bonjour Blackgotan,

Just a quick reminder that this board happens to be an Input/Output card for the miniDSP kits. 1 x 4 plug-ins happens to be "one" of the many plug-ins we will soon have, so our I/O cards will not fit all our plug-in configuration (simply impossible). Now to why only 1 output, because SRC ICs with multiple outputs requires quite some engineering (or multiple IC) and would stear away from the concept of providing low cost DIY friendly platforms (making it more expensive). As we tried to explain it in our product concept page, every project out there is different, and the simple idea that a single board will fit most DIYers dream is pure fantasy.... What's more useful, is to give you the flexibility people need to build the configuration you need (1, 2, 3.. SPDIF outputs..) If your application needs more SPDIF outputs, just stack more than one card. Hope this makes sense.

The single output isn't intended as a digital output for the crossover (SPDIF/Toslink amplifier being quite rare...) It's more intended to link up multiple miniDSP kits. E.g Feed one minidSP kit on your Left speaker with a SPDIF/Toslink cable from your receiver/source. Audio gets processed for that speaker. How you want to use the SPDIF output could be of many ways but here are some example:
- send the original L&R audio to another miniDSP kit on the Right channel (active speaker configuration in 3 way for example)
- Or, in case you have a single miniDSP in stereo crossover configuration, you may want to send that source to another SPDIF device (e.g. your subwooofer)...

All that will be much clearer in our datasheet/application notes, which may then trigger more questions.

As for your question of a bundle. Yes, we will bundle them together to have SRC + miniDSP kit.

Best Regards,

Tony
 
Hi
Lets assume that I would like to use both the analog input and the digital input in the minidsp + minidigital combo? Not at the same time but with some sort of switch. this would enable me to feed my squeezebox directly into the minidigital and also keep input from my turntable via an analog preamp.

Is that possible?

Thanks for this really cool initiative.

Regards
Andreas
 
Lets assume that I would like to use both the analog input and the digital input in the minidsp + minidigital combo? Not at the same time but with some sort of switch. this would enable me to feed my squeezebox directly into the minidigital and also keep input from my turntable via an analog preamp.

Hello Andreas,

In answer to your question, there are a lot of potential combination (yours being one of them) so the board can't do them all. This beind said a little trick can be done to make this work which is routing the analog audio input (I2S out ch5&6) to the SPDIF output (by correct jumper selection) and looping it to the 2nd SPDIF input with a short SPDIF cable.

With this little trick, you'll be able to toggle from SPDIF 1 to SPDIF 2 with a single toggle switch. A bit of a workaround, but would work fine in your case.

Hope this makes sense, otherwise, wait for our spec sheet/application notes which will give you a better idea of what I meant.
 
superb -- However just one additional question. Is it then possible to use 2 minidsp boards to have a stereo 4 way channel crossover ? and also have the minidigital board doing the above trick. ?
This might require an additional minidigital board i gather ?

thanks again

/andreas
 
Ok, I can't answer this question directly without knowing a bit more of your system. Where would the miniDSP kit be? Would there be in each loudspeaker (active configuration) or just built into a custom 2x4way custom amplifier?

The reason I'm asking is because it will affect how you will be sending audio from one board to the other. Once you clarify that point, I can try to see the solutions we have. Thanks.
 
Hi again

OK here goes:
standalone box: with stereo 1xanalog input and 1x digital indput (switchable as above), volume control and 2x4 outputs driven by 2 minidsp boards.

effectively a simple preamp with build in stereo 4 way crossover.

I hope this is clear.

Regards
Andreas
 
Quick question.

Would it be possible to configure one minidsp card + one digital io card like this:

spdif input to dsp card. Dsp card is then used as 2way stereo crossover. Then spdif output goes to external dac feeding my tops, and the analog outputs on the minidsp feeds the subs?

To clarify: can I use the digital out as one output, and one pair of the analog outputs in a stereo crossover configuration?

Also: Would it be possible to feed an i2s compatible DAC for one of the output pairs in a 2way stereo crossover config, and use the spdif output for the subs?

(In case i get another dac someday and want to use both).

I hope im not to vague with these questions, english is definately not my native toungue.

/jonas
 
standalone box: with stereo 1xanalog input and 1x digital indput (switchable as above), volume control and 2x4 outputs driven by 2 minidsp boards.

effectively a simple preamp with build in stereo 4 way crossover

Andreas,

It does make complete sense and I have an idea in my head of how to make it work but never tested this little trick so before claiming anything, we'll do some tests and let you know on the results. I don't see any reasons why there would be any problems with this config this being said.

Will get back to you quickly once test fully performed,

Tony
 
Quick question.

Would it be possible to configure one minidsp card + one digital io card like this:

spdif input to dsp card. Dsp card is then used as 2way stereo crossover. Then spdif output goes to external dac feeding my tops, and the analog outputs on the minidsp feeds the subs?

To clarify: can I use the digital out as one output, and one pair of the analog outputs in a stereo crossover configuration?

Also: Would it be possible to feed an i2s compatible DAC for one of the output pairs in a 2way stereo crossover config, and use the spdif output for the subs?

(In case i get another dac someday and want to use both).

I hope im not to vague with these questions, english is definately not my native toungue.

/jonas

Jonas,

Your description is perfectly clear and makes complete sense.

The answer is yes, you will indeed be able to feed un-filtered analog audio from the analog audio inputs to the SDPIF output thanks to our very flexible I2S routing. We'll be working on the manual and datasheet this week, so this will make more sense to you.

One little concern in this "mixed configuration" is the fact that the DAC will need to be "time aligned" to the DSP. In other words, you will need to make sure that audio is time aligned between the analog outputs from miniDSP and analog outputs from your DAC. It maybe that you simply have to tweak the delay to get them time aligned properly.
Do you understand what I mean? I'll dig our end to end delay with the stereo Xover (analog input to digital input) to figure out if that will be an issue. In the mean time, do some homework on your side to figure out the end to end delay (Digital in - > Analog out) of your DAC.

Will follow up once I have the information you need.

Hope this clarifies your questions,

Tony
 
To Andreas & Jonas,

Just a follow up to let you know that no, I haven't forgotten about you! :)
We've just been extremely busy with testing, new plug-in release so haven't had a chance to test your configurations. I'll get on it in the next few days and get back to you.

Sorry for the delay.

Tony
 
Hi Tony

No worry -- I am eagerly looking forward to see if my configuration is possible. It would enable direct connection of my squeezebox to the minidsp as well as still using the good old analog preamp with my turntable and other analog sources.

Regards
Andreas
Andreas,

Your configuration has been tested and it works fine. Here is how you would do it:
- Configure the miniDSP plug-in to I2S digital input source
- Use a 2 pole switch on the I2S routing header of the miniDIGI, for the I2S_Data_In_ch7&8 (Digital input channel to the plug-in) to toggle between the I2S feed from the SRC and the Un-processed signal from ADC on I2S_Data_Out5/6.
Besides an expected level change between these two sources, it worked like a charm.

Please have a look at our newly released miniDIGI user manual for more information.

Hope this info helps
 
Hi Tony

I I understand correctly, this still leaves the digital out unaffected, so it can be used to daisy chain to another minidsp/minidigi set of boards ?

/andreas

Yes Andreas that's correct. By routing the I2S data correctly, you will be able to send the "un-processed" audio to another board via the SPDIF out.

Please have a look at the miniDIGI user manual for more information. This exact configuration is explained in detail, along with the correct jumper configuration required.

Hope this makes sense.
 
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