I have currently built a couple of little class d audio projects 1 a train/cosmetic case using 4" coaxials and an amp from P/E 20w per ch. I am also currently working on a cigar box stereo set up. Both of these I want to use Bluetooth with and I currently am using a little rechargable module. I am considering hardwiring one of these or a nother module of some sort in but I would like to maybe power it from the pwersupply and or battery currently 12v 8ah sla battery. If I attach a 12v to 5v chip setup or converter how much extra power loss will I have other than just what the bluetooth module uses? will it be negligable? or should I stick with leaving them rechargable and on their own power? any opinions I don't want to suck the units battery dead stepping down power and all just to run BT.
Sure hifi has a module B.T 2.0 for under $20 that runs off 12v. I have used these. I do change the feed back resistors so it has more output.
The bad is that there is slight Bluetooth risidual dual noise. I have bought about 10 different modules and they all have the same noise. However hi-end comercial speakers don't. I haven't been able to solve issue yet.
The bad is that there is slight Bluetooth risidual dual noise. I have bought about 10 different modules and they all have the same noise. However hi-end comercial speakers don't. I haven't been able to solve issue yet.
This has been discussed in a couple of other threads. There is noise from BT module that is picked up by amp due to a ground loop problem resulting from powering the amp and BT from same source. You need a DC isolated converter from 12v to 5v to keep this noise from showing up. There is no way around this apart from making your own integrated PCB that includes both amp and BT. Use the Mutata MEE1s1205sc converter. It works very well and provides all the power that the BT needs (50mA I think).
I tried everything to get rid of the noise and this is the only thing that works apart from using two separate power supplies or batteries.
I tried everything to get rid of the noise and this is the only thing that works apart from using two separate power supplies or batteries.
Thanks for response regarding BT noise. I am a little confused. I understand isolating the power supply but as soon as I hook up BT module to amp module the grounds are common again be couse of patch cord. How do I isolate those grounds?
Once the chip isolates the DC to DC conversion the grounds on the signal out of BT to amp in don't seem to matter. You can use optional cap on output to decouple but hat is optional.
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