Strange noises when using L/R AUX inputs on an ADAU1761
Hi guys,
I'm experiencing some strange noises with my ADAU1761 eval board. It kind of sounds like clock noise, but it also is changing in frequency and changes pitch. It's a bit like whistling wind.
It seems to enter my signal only when I turn on either of the AUX L and R inputs (registers MX1AUXG and MX2AUXG). If these are muted, then all is quite, and my differential inputs sound clean.
I should also mention that my DSP core is very simple. I have stripped it down to pinpoint the issue. My schematic only consists of inputs 0 and 1 going into a two channel fader and then go my DAC0 and DAC1 outputs.
Has anyone else experienced anything like this?
Any help would be greatly appreciated.
Thanks!
-Pete
Audio Signal Processors
strange
noise
SigmaDSP Audio Processors
adau1761
Hi Pete,
I'm very sorry that I didn't respond to this sooner. I must have lost track of it in the lead-up to the New Year, when we got quite busy with support requests. Do you happen to have an example project that showcases the problem so I can test it? You can attach it to a forum post as a zip file.
Brett
No worries, I was able to move my project forward by keeping my volume settings really low. But I would appreciate your help on this. Attached is my stripped down project and schematic that still gives me the strange noises. My hardware is the EVAL ADAU1X61EBZ 110324_1 Rev B, and I'm using the USBi to upload (EVAL ADUSB2Z 080624_1) Thanks!
Hey Brett,
Have you had a chance to test this out yet?
Let me know,
Thanks!
I'm very sorry that I let this one get by. I lost track of your question.
I gave this a try on my evaluation board, and on the first download attempt, I wasn't able to get any audio at all passing through the board. I wasn't sure what settings might have been causing the problem, so I used the "All Inputs, All Outputs" preset button in order to get the board in a known working state, and then audio began to pass through.
I used a simple audio source on the single ended inputs (3/4) and then left the differential input floating. I turned the audio source on and off, and also played around with all of the mixer settings, and I wasn't able to observe any sort of whistling sound like what you described.
Would you maybe try again with a new project and click the "All Inputs All Outputs" preset button in the first page of the hardware configuration tab, and use that as a starting point? Perhaps this can all be traced back to some incorrect register setting?
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Thank you,
EZ Admin
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