Tutorial: Connect Mini/Pro to other I2S DACs

Thanks @j.eeken1.

It seems I just connect GNDA and GNDD together in one place to avoid a loop.

I had sort of done that with the solder jumper as on RHS of the schematic.

The other adjustment I’ll make the ground plane of the board GNDA again, and just make sure its isolated from the Luxman recevier chassis and the Mini V3 as those would cause a ground loop.

By the way. Great looking receiver. Love these vintage stuff.

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Thanks. I’ll be posting the finished article on this forum when it’s done.

I ordered the Wondom »S/PDIF AND IIS/I2S AUDIO SIGNAL TRANSCEIVER« board. Bu I don’t know if this is a good idea. I don’t want an extra conversions in my signal chain and I don’t know if there will be one with this connection.

I have that board to. I use it for testing. if you mean that there will be quality loss. It won’t.
PCM will just be passed through.

A week ago Wondom released a video on youtube how to connect it with the Jab5

Cool. But one question back. Could this issue be a conflict between the Clock which expect the Wondom and the delivered from the Up2stream. For example: For Bluetooth and Analog there will be a 48Khz used and for WiFi 44kHz. If the JAB5 expect 48kHz and get 44kHz he will be confused. Normally this will be controlled via the Master/Slave switch, right? But I heard that the ADAU1701 standalone DSP-Board always works as Master.

The Up2stream boards all have an 16bit/44.1khz output. No matter what the input is. So you can configure the ADAU1701 boards with 16bit/44.1khz. The ADAU1701 dsp has 4 digital inputs and if you connect a second source to it that outputs 24bit/48khz, than you configure it to 24bit/48khz and it still accepts 16bit/44.1khz without distorsion.

The company “Analog Devices” that developed the ADAU1701 dsp chips has it’s own community. You may ask there to help you with your problem. They have way more knowledge then me.

Sorry, but I’m still talking about the JAB5 Amplifier board. I don’t have the ADAU1701 DSP-Board. But the JAB5 has the same chip on board as I know. Perhaps the DSP-board can have more inputs but I have to deal with the inputs that are available on the JAB5, and this is only one I2S Input.
I don’t know enough about the technical details, I’m just frustrated, and try to find the source of the problem. If the Up2stream only sends 44kHz/16Bit I don’t understand why streaming over Wifi is not working but via Bluetooth or analog.
The solution to use the SPDIF conversion board as a bridge is ok if I don’t have any loss of quality. It’s not the philosophy of integration which I would reach, but if it works…
I will write some more infos if I took a look in the System with Sigma Studio.

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Yes, I know you are talking about the Jab5. But, the onboard bluetooth of the Jab5 supports Aptx-HD 24bit/48khz. When you use that too or connect another source to the SPDIF board, you can leave the settings in Sigma Studio to 24bit/48khz. That was what I tried to tell.
I can really understand that you are frustrated by now. I was suggesting the Analog Devices community, because these are pros that may can identify your problem.

Finally I fixed it with Sigma Studio. I had some issues before it works – combinations of drivers, switches, what to power on first. But at the end I got it.
The reason was not the sampling rate, it was the LRCLK polarity. After switching it it works. Don’t know why, but it works, also with bluetooth and USB.

Now the fun part. I have the four potentiometer connected to the JAB5, but I want just a 2.0 system. So I don’t need the crossover potis and also I want just one volume controller. My idea is to have

  • one poti for volume
  • one poti for balance
  • one poti for treble
  • one poti for bass
    The only concern is the volume controller. The Up2stream has also a volume controller. I recalculates the digital values.
    Can I deactivate the volume controller from Up2Stream?
    How to realize a IR remote volume controller?
    Any experiences or ideas?

Currently no, will consider to make a new command to use static volume for up2stream board, as it’s not a problem for DIYers :grin:

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Hi I’m back. Now I build up my complete setup. And I have still the issue with the distorted signal. But know I recognized that’s only in the right channel. Left channel works fine. In my first test I had only one speaker connected. And this is the reason why the problem disappears as soon as I switched the LRCLK.
With speakers connected to both channels channels the distortion can be switched from one channel to the other if I switch LRCLK. I also tried an other Up2Stream Pro without any changes in the setup. Same issue.
Definitely the I2S signal over Network connection creates distortion on the right channel.

I will start a new discussion, because this is not related to your original topic: Up2Stream I2S distorted right channel only via network


there is one thing i do not understand with using an external DAC / external amp with I2S connection:

When using an external DAC the volume control still seems to work, but with an I2S amplifier not. But both are feeded only over the same I2S data stream.

Has anyone an idea where is the difference?


Hi Stefan,
I’m not sure I can help you any further as all the DAC’s I have are connected to separate amplifiers. It sounds like you are feeding I2S into a digital amplifier, correct?


Hi Steve,

i will feed an external amp with analog input like you :slight_smile:

So my plan is to use a very good external I2S DAC and then use an amp behind with fixed gain. Of course an I2S amp would eliminate the D/A conversion, but what i have learned is that an I2S amp will loose the volume control (and i still don’t understand why).

Hi Stefan, what do you mean with »I2S Amp«? If you use a DAC with I2S input you can do the volume control at the analog Amplifier. You don’t need the digital volume control.
If you use something like Wondoms JAB5 you double the volume control. because the Up2Stream has a digital volume control and the JAB5 too.