TOPIC:

I'm going to buy the MiniDSP and digital in/out module.

Maybe a dumb answer, but I would like to be sure, that I can have spdif input from my computer into the digital i/o board, and analog out of the DSP module.

What I'm going to bulid is: Computer optical out --> digital i/o board --> MiniDSP (2 way crossover plugin) --> 4 analog out to four channel amplifier --> two 2-way loudspeaker.

I guess I need one MiniDSP and one digital i/o board. But do I need rev. B with optinal transformer when using only optical input?

In the future, I will have digital input in amps as well. If this is coaxial, will the transformer version then be the better choice?

Hello,

No such thing as a dumb question!
If your objective is to use optical only, then transformers won't be of much use indeed.

In our in house tests and listening sessions, we did notice a clear difference between Isolated and non isolated version. Having the I2S selector on a source selection switch, it was really easy to do a blind A&B test and most people would notice that audio resolution with the transformer was improved. Audio was much cleaner and very comparable to the optical input.

Whether you want to spend the extra 10USD or not is your call.

Hope this information helps.

Thanks for the quick reply. The 10$ isn't really the problem, but it might be. I Denmark we have a lower tax limit. If I get under this value (approx. 270 US$), I don't have to pay import tax.

I didn't get an answer on the output part. Can I use all types of outputs - both analog and digital using digital input? I would also like to be able to mix the outputs. I have a number of connexeclectronic NXD TDA8950TH modules. They should be very good at bass reproduction but lack in high frequencies. Therefore I might buy one of your Miniamps as well for the top of my system (Markaudio 4" full range or Tangband 4" fullrange)

Therefore I would like to use analog out for my "TDA8950th/bass system", and digital out for the "Miniamp/topsystem".

In answer to your questions:

Can I use all types of outputs - both analog and digital using digital input?

Yes, All outputs out of the miniDSP are available both in Analog (RCA out) AND Digital I2S format (I2S out 1-4). The I2S/Analog routing is now clarified as follow in the datasheet:

Digital Inputs/Outputs:
I2S input channels selectable on I2S_Data_In1&2
I2S output channels selectable on I2S_Data_Out1/2/3/4
Unprocessed signal from selected input (I2S/Analog) available
on I2S_Data_Out4/5

Mixing the outputs will however be an issue since there aren't any mix out on the miniDSP (unless it's a miniDSP mixer plug-in). You can easily get around that with the good old resistor trick to make it work.

Hope this info helps,

Sorry, but I don't think that was an answer to my question.

I'm going to use MiniDSP and spdif in/out card, so no need for I2S routing.

What I will do, is to have spdif input and both analog out and spdif out. Maybe I will use your minamp for topsystem, and analog amp for subsystem. Therefor I want to be sure, that I can use the 2 way stereocrossover with your miniamp, and my own (powefull) analog amp. Or with a digital amplifier with spdif input, and again a more powerfull analog amplifier for subwoofer.

Ok, maybe the word I2S routing is a bit confusing (but that's the one we've been using over here in our engineering department . I think that by the time we issue the UserManual for the miniDIGI + miniAMP (in the next 2 days), you'll understand what I mean.

I understand your configuration and let me try to explain what I mean by I2S routing:

The way miniDSP and any other I/O cards(miniAMP/miniDIGI) share audio in our systems is using I2S signals. How these I2S signals are "routed" on the expansion bus is done by a jumper configuration on each I/O card.

So a miniDIGI has 4 available channels of I2S input (select which channel you want to route your SPDIF->I2S data on the Bus) and 4 channels of I2S outputs (Select which I2S channel (from the I2S bus again) you want to convert from I2S->SPDIF.
Does this make sense?

Alright, so say you input your SPDIF signal to the miniDIGI, it gets converted to I2S by the SRC + Digital receiver. You then need to "decide" which I2S channel you want to send it to on the I2S Bus (one of the 4 available). Ok?
In your case, you'll want to send that channel to the miniDSP kit, stacked below your miniDIGI board. As per the plug-in datasheet, the input channel for any plug-in is on I2S_IN_ch1&2. So you just need to route your I2S signal to I2S_IN_ch1&2.

Signal gets processed by the miniDSP. Boom, it time to get it out (digital and/or analog)

Looking at the datasheet of each plug-in, it details how audio is routed to 2 locations:
1) To the miniDSP DAC (analog out)
2) AND doubled up to the I2S bus so that you can grab that processed audio in a different channel. In that case, looking at the plug-in datasheet it's on I2S output channels: I2S_Data_Out1/2/3/4.

In your case, if you want to get the miniDIGI SPDIF output working you will first need to route an I2S signal to the miniDIGI:
1) On the miniDIGI board, configure the jumpers to grab the I2S_Data_OUT1&2 or 3/4. This way you get the same signal as the analog DAC out from the miniDSP kit.
(I think that is what you want here)

2)Another option is to select the un-processsed signals on I2S_Data_Out4/5 if you just want to loop through the system and get your "unprocessed, de-jittered SPDIF input" for a different source (e.g. another miniDIGI board on the other side)

3) As for the miniAMP configuration, it's the same. You just need to configure the miniAMP I2S routing on that card to "grab" the correct I2S channels (out1/2/3/4) from the I2S expansion bus.

Does this make a bit more sense now? Our I2S + I/O card combo is very flexible and it can become a bit confusing. But basically, you can configure it the way you want, grabbing the channels you need from the I2S bus.

Hope this clarifies and answer your questions. As I said, all this will become much clearer when the user manual comes out.

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I have read it now, and it makes sense. Now I'm just going to wait for the miniAmp - especially the price. Is the miniAmp based on texas instruments chips/truepath?

Glad that it now makes sense. Have a look at our newly released miniDIGI user manual for more information. It's available in the download section of our website.

The miniAMP modules are in production and should be tested/burned in and ready for shipping by early next week. The module is indeed based on a TruePath IC from TI.

Pricing to come out once we have final confirmation of the complexity of manufacturing of the module. (maybe one of the hardest to manufacture so far!) Such a tiny board, components on both sides and once again lots of flexibility.