You guys are very professional with the electronics, I’m more likely familiar with software
I have no clear idea for the issue. Anyway, one point might help to debug, the 3.5mm jack might not connect the detecting pin to GND, so the 4 segments plug might have issue.
not fault actually, but because of the unclear specification of this connector, we only connected the very outer PIN to GND, so it might cause issue for some earphone with 4 segments including MIC. But this should not cause this ripple noise, more likely some hollow sounds. I prefer to believe some interference came into the system, eg the RF signals. Btw, could you hear this noise with earphone?
And you might also connect the GND with the AMP board to determine if the noise came from AMP board.
That could very well be. I have great difficulty finding the source of this. At least I am sure it is not a mobile phone or something like that. I have also placed this configuration in another house, but also there I have the same.
But when I change the Up2Stream Mini, and put in a S10 (I have tried 2 of them) or a Pro, the Ripple is gone!
The fact that the interference problem is endemic to all your mini’s but not to your pro version board is very puzzling, I don’t suppose that you have a DAC board to see if the problem exists thru I2S as well?
Hi Ernst,
To be honest, I really don’t know! But going thru what you have already tried in my head I couldn’t think of anything else.
I only have one mini and have used it successfully in two different projects, both times with two different add on DACs with no issues and no noticeable humm, ripple or interference.
I look forward to hearing your (hope positive) feedback once you try!
Cheers,
Steve
Hi Ernst,
I think I can answer that, what Frank is saying is that the S10, Pro and mini use the same digital to analogue conversion circuitry/hardware which is embedded within another IC (main chip) there are limitations to this practice, probably why the documentation says: ‘For example, it supports adding an ESS 9023 DAC to increase the sound quality’
Maybe Frank or one of the Arylic hardware specialists could shed some light on that?
I think that I mentioned previously that from my own experiences with the only mini that I own, using it in two different projects I haven’t experienced any issues anything resembling the noise that yours is producing.
Interesting!
For a long time I have had issues with the Up2Stream Mini. Tested with three different models of active speakers, there was a ‘ripple’ interference in the audio signal. I have been looking for a long time to find the cause, so far not successful.
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I am happy I have been able to find out, that the issue is with the Up2Stream Mini. I guess it is save that the Mini has sensitivity to noise. And that adding the DAC board solves the issue.
Personally I prefer that the sentivity/ripple of the Mini would be solved. Adding a DAC board for each of my builds does drive up cost.
Just found some extra information that confirms my thoughts.
The Mini uses a MCU-chip with an integrated DAC. In fact the MCU handles all the ADC/DSP/DAC/BT functions, so a system-on-one-chip design. If you remove the top board of the Up2Stream Mini, the MCU is visible: