@ andre.m - source?
@ Gus - I only did a quick check of the VLSI web site. For my project, Iām not interested in adding any hardware, or modifying the music player board. I prefer to buy a board that has line out connections designed for connection to an external amplifier.
@ andre.m - Thanks. Where is this schematic from?
@ andre.m - Thanks. Our posts crossed.
@ Gus - And take the responsibility for the RLP-based driver as well and I will send you a magnificent Christmas present! Itās not as easy as hoped for.
Please please please
@ andre.m - While the change is simple on the PCB, a change is very difficult for a productā¦stock, distribution, part numbers, machine setupā¦customers who do not want the new versionā¦
However, I think this is a good change in the future.
ok guys, to assist me and others in actually using the music module we need a little extra hardware and some modifications of the module. Is it possible that some of you would draw the schematics and explain where to modify the existing module.
I have looked at the music module schematics and the suggested line-out schematics from the ic. But I dont want to harm anything, and would really appreciate the effort very much.
@ njbuch - we will gladly help. hopefully soon
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bump, I have tried for 6 months getting decent sound from the music module, and I am REALLY eager to close this projectā¦
Can anyone help wiring the music module correctly and noise-free with an external amplifier??
Hi,
if the noise is only there when no music title is playing, perhaps it is possible to fill the gap with a title that cannot be heard ( frequency below 40 Hz or higher than 20.000 Hz).
Regards
Roland
Maybe this is not the answer you are looking for, but why donāt you stay in the digital domain a little longer? By using the I2S output the VS1053 provides you are able to connect to a DAC of choice with better sound properties and less cross-talk/noise.
A couple of things to keep in mind:
-The music module you are using probably has the I2S route wired to ground via pull down resistors.
Then you have to use a different VS1053 (break-out) board like the one Sparkfun sells:
https://www.sparkfun.com/products/9943
-A couple additional lines of code have to be added to your source code in order to enable I2S output: VS1053: How to enable I2S ? - VSDSP Forum
-If you connect it to a DAC of choice, then have a look at the following guide coming from a Dutch website: VS1053 and VS1063 I2S outputs
Hope this helpsā¦
@ RoSchmi - interesting idea, I think the zero-volume actually is as silent as possibleā¦
@ djagab - very interesting idea, I think other people might be able to do what you propose, but to me it is a little too much hardware-tinkering.
Anyone else having ideas for line-out connections using the existing music module?
Do I understand you correct Andre, you got this info from VLSI ?
I finally got around to connecting my Panda 2 with Music Shield to this amplifier board:
https://www.parts-express.com/2x8w-@ -4-ohm-tpa3110-class-d-audio-amplifier-board-onlyā320-329
I connected the headphone output from the Music Shield to the headphone input of the amplifier with a 3.5 mm cable.
Iām driving this āin-ceilingā stereo speaker (sitting on my desk):
https://www.parts-express.com/dayton-audio-cs622c-6-1-2-stereo-ceiling-speaker--300-412
Iām using separate wall-wart power supplies for the amplifier and the controller board.
The amplifier uses this power supply:
https://www.parts-express.com/12-vdc-3a-power-adapter--320-312
The sound is very good. No distortion and no extraneous noise or hum. There is no noise between songs.
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Thatās really good.
I have looked at the parts, and they are not that different from the stuff I am using. So the only difference is the shared power-supply trick.
Can you confirm that it does not work with a shared power-supply? Or is it the specific power-supply that drives the amp which is the primary point here?
@ njbuch - If I plug the Panda into my computerās USB port there is a lot of noise. If I share the amplifierās power supply with the Panda it actually doesnāt play at all. I think there may be a ground loop problem or something??
Having two power supplies is not ideal 
2 separate power supplies will work as then there is no common ground and the GBUF line is effectively floating.
If you connect the grounds then you will get a problem. This is why plugging in the USB causes an issue. 
I see the same thing. If I connect my scope to any point on a board with USB disconnected, I get a floating ground effect on the scope display. This is with the scope probe ground not connected to the ground on the board.
If I connect the USB to the board then the scope display behaves as if the scope ground is connected. If I power off the scope and the computer, board etc and check resistance on the GND, they are all interconnected through the mains power ground. I have yet to remove the ground lead on my scope for this very reason.
Yep, I love it when the experts are working. Hope you will find a way outā¦ ???
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Hi again, I am really sorry to tire you all with this line-out challenge. I know that Dave are really buzy earning money (I wish my Gadgeteer skills was at that level :think: ) - so his attempts are in the pipeline.
Can anyone else help me out of this misery, I already suspended my potential customer meeting twice, as I am not able to demonstrate a Gadgeteer system playing sound in a speaker. Which is REALLY embarrassing.
Hi Niels, I was going to send you an email.
I am having no luck with getting this to work with the GHI board. I still get lots of noise on the output from the amp. Even when playing back there is noise compared to the clean signal you get from a headphone.
Ahh, thats sad 
thanks for the effort anyway. I am now having the DFRobot module tested in the similar setting. Not optimal, but a workable setupā¦
Still hoping that some of you come up with a good ideaā¦ 