Hello all
Got a tsunami-super-wav board connected up and no matter what I do, there is this very annoying, constant whirring noise from the speakers.
Tried running the tsunami-super-wav from it's own 5v (instead of sharing the 5v supply to the processor). Slightly better, but not much.
Added a ferrite coil and a couple of caps to the tsunami-super-wav 5v terminals.... improved it a little more.
Screened cable from the tsunami-super-wav to the 15w amp.
Not sure what else I can try.
I have noticed that certain SD cards make more noise. Bought some Gigstone ones off Amazon and they where rubbish. VERY noisy.
Tried an old Sandisk and the noise was much less.
I have noticed that a lot of SD cards can create a lot of noise on certain MP3/Wav modules.
That surely must be down to poor shielding/supply on the tsunami-super-wav SD supply?
Annoying!
I really wish they would make a version of this board that takes USB or had some kind of onboard memory, SD cards just don't take the beating
Verify grounds - to give noise a place to go. Solder loose wires. Verify "empty" pins are "tied" (low or high depending on their nominal state) - so they are not acting like antennae. Try a different power supply - some are noisy.
A schematic shows the wiring as it should be, but doesn't show how it is. I know the schematic is correct, because it's simple and it works.
I have already pointed out what the problem is... it's the SD cards. Different cards create different amounts of noise. A good quality card has got rid of the noise as I said.
So I have made an effort thanks. How can I add decoupling to an SD card (unless I somehow add something to the Tsunami card)
I already mentioned the sound card has it's own PSU
Would not surprise me if changing sd cards has led to making a bad contact 'good'.
Maybe you will experience it go bad again. Till then: good luck!
If the quality of sd cards really is the issue, it would be worthwhile mentioning the card brands and types that you have used.
Well its not a bizarre comment.... it's appears to be the way it is...
Sandisk - best ones. Barely any noise.
Gigastone Micro SD - Terrible noise. Sent those back.
Polaroid Micro SD. OK, but not as quiet as the Sandisk ones.
Some unknown make I found lying around. Actually not too bad.
PNY (no idea who they are). Pretty noisy.
So, clearly something on these cards affects the way they work on the power supply.
I have had this issue before with USB sticks in JQ8400 MP3 modules. I had bad noise on the output and could not work out why. Changed the USB stick and it went away.