I have a digital preamp with some built in dsp for volume eq etc.
I'd like to share power supplies with the tpa3118 chip amp. However, it is giving me a noise which I assume is some sort of clock interaction (much like 2 mono tpa3118 amps generate on the same psu).
Is there a good work around for this?
I'd like to share power supplies with the tpa3118 chip amp. However, it is giving me a noise which I assume is some sort of clock interaction (much like 2 mono tpa3118 amps generate on the same psu).
Is there a good work around for this?
Yes. What is the preamp? What are its power requirements and does it have balanced connections out?
More info, please 🙂
More info, please 🙂
It's a zoom eq that runs on 9v and 500ma. Unbalanced in this case.
I have a dc to dc converter taking the tpa3118s 24vdc and running it to 11vdc then a linear regulator (lm317) taking that to 9.5vdc. The linear reg doesn't help. The tpa3118 is introducing digital noise to the preamp through a ground loop I believe.
I have a dc to dc converter taking the tpa3118s 24vdc and running it to 11vdc then a linear regulator (lm317) taking that to 9.5vdc. The linear reg doesn't help. The tpa3118 is introducing digital noise to the preamp through a ground loop I believe.
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Ah, I was going to suggest what you have already done. I am sure one of the more learned members can help. Perhaps supply a schematic.
I think it has to do with how the tpa3118 likes to have a slave mode when two or more share a power supply. Something to do with clock sync. Maybe there's a way around it. I can of course power the pre via a separate psu, but I'd like to figure this out. Besides the clutter and already having power there anyways, I figure digital problems will arise again. May as well learn something.
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I had similar sorts of problems running a Chromecast Audio to a TPA3116. I ran a 5V buck to convert 16V for the amp to 5V for the CCA. Had terrible high speed chipmunks or squirrels in the wires. A ground loop isolator between the CCA and the amp was one way to solve it. Eventually I bought a high power isolating DC DC converter board and ditched the isolator. Sadly, those boards seem NLA.
J.
J.