Hello,
i have a really weird problem which i cant find a reason or solution for so i thought i ask here for some help. Im trying to fix noise and pop sounds now for months, but i still couldnt eliminate it.
Ive made a wiring diagram to help understand my circuit. In the Diagramm you see how i connected power and some Signals in my System.
As long as the PCM5102A is not connected to the Amplifier, the signal which comes out of it looks very clean on the Oscilloscope. But as soon as the Ground of the Amplifier and the DAC are connected (e.g trough the RCA cable) there are huge voltage spikes with about 3V on the Signal connection.
i tought that could be a ground loop problem, but since i am using an isolated dc dc converter that should not be the case anymore.
Do you have any idea how making a ground connection to the AMP can lead to these voltage spike and maybe how i could solve that?
i have a really weird problem which i cant find a reason or solution for so i thought i ask here for some help. Im trying to fix noise and pop sounds now for months, but i still couldnt eliminate it.
Ive made a wiring diagram to help understand my circuit. In the Diagramm you see how i connected power and some Signals in my System.
As long as the PCM5102A is not connected to the Amplifier, the signal which comes out of it looks very clean on the Oscilloscope. But as soon as the Ground of the Amplifier and the DAC are connected (e.g trough the RCA cable) there are huge voltage spikes with about 3V on the Signal connection.
i tought that could be a ground loop problem, but since i am using an isolated dc dc converter that should not be the case anymore.
Do you have any idea how making a ground connection to the AMP can lead to these voltage spike and maybe how i could solve that?
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What happens if you only connect ground (but leave the VOUT lines disconnected)? does the output of the PCM5102A change?
After the pop occurs, does the output eventually settle and sound passes through or does the output of the DAC stay clipped?
Do you have any DC blocking caps in the design? Maybe a schematic would help.
After the pop occurs, does the output eventually settle and sound passes through or does the output of the DAC stay clipped?
Do you have any DC blocking caps in the design? Maybe a schematic would help.
Same happens on the signal line when only ground is connected.
The voltage spike is only very short pulse and goes dirrrectly back to ground potential.
Since the PCM5102A is already ground referenced there is no dc blocking cap on this module, but one the Amplifier side there is one electrolytic dc blocking cap.
I kind of think the PCm5102 is misinterpreting some i2s data, but then i would have no idea why this only happens if ground of amp and dac are connected.
Tomorrow ill try to do a schematic of the most important parts.
fyi im using the 3e Audio TPA3255 board: TPA3255-2CH-260W | 3e Audio
and a China PCM5102A Module: PCM5102 DAC Decoder I2S Player Uber ES9023 fur Raspberry Pi-in DAC aus Verbraucherelektronik bei Aliexpress.com | Alibaba Gruppe
The voltage spike is only very short pulse and goes dirrrectly back to ground potential.
Since the PCM5102A is already ground referenced there is no dc blocking cap on this module, but one the Amplifier side there is one electrolytic dc blocking cap.
I kind of think the PCm5102 is misinterpreting some i2s data, but then i would have no idea why this only happens if ground of amp and dac are connected.
Tomorrow ill try to do a schematic of the most important parts.
fyi im using the 3e Audio TPA3255 board: TPA3255-2CH-260W | 3e Audio
and a China PCM5102A Module: PCM5102 DAC Decoder I2S Player Uber ES9023 fur Raspberry Pi-in DAC aus Verbraucherelektronik bei Aliexpress.com | Alibaba Gruppe
Also maybe try 3v battery power for the Bluetooth. I recall others having issues with sharing power with similar arrangements.
i did now test it with differente power supplys and can confirm it helps a lot !
Very rarely there is still one click / pop sound.
I dont really undestand how there is still Interference over the Powersupply if i am using a isolated dc/dc converter.
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