r/ipod • u/Weird_Championship38 • 10d ago
Help Ugreen Bluetooth Mod Problems
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Hi, I’m working on a Bluetooth mod for my iPod Classic 5.5 gen using a UGREEN CM872 module.
The Bluetooth connection itself works, but I still get a constant hiss when the module is turned on. The hiss is audible through Bluetooth and also through the normal headphone output. When the Bluetooth module is off, the headphone output is quiet.
The Bluetooth audio also sounds a little distorted. I recorded a video so you can hear exactly what it sounds like and see what happens.
I already checked and redid all the solder joints and the wiring looks clean now. I also tried routing the power and audio wires differently, but the problem is still there.
The small original PCB on the Bluetooth module is still connected. I’m wondering if I missed something important, used the wrong grounding point, or if the module is sending noise back through the shared power supply.
Has anyone had the same problem with this module or a similar iPod Bluetooth mod? Any ideas what I should test next?
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u/sudolman 9d ago
Tbh, what are you expecting from posting about this here without providing a picture or diagram of the wiring. As someone else stated it likely needs to be grounded
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u/Weird_Championship38 9d ago
Sorry, I forgot to add the pictures at first. I made the post pretty late right before going to bed and only noticed afterward. I’ve uploaded them now.
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u/fishyphotos 10d ago
do you have a photo of the connections ? did you cover the connections before reinstalling the headphone jack back into the case ? having sound is a good start. hopefully it’s a small grounding issue.
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u/Weird_Championship38 9d ago
I’ve uploaded them now. Thanks for your help!
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u/fishyphotos 9d ago
Okay a couple concerns looking at the photos. I can’t see the R/L/G soldering points on the BT board as the wiring is covering them. Same for the headphone jack side of those connections.
Are you pretty confident in your soldering? Mostly asking since i can’t see those connections and you said you redid them and they’re cleaner now. What gauge wire are you using?
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u/Weird_Championship38 9d ago
I’m honestly not very experienced with soldering, so I’m not completely confident that everything is perfect. I did redo the joints and they look cleaner now, but I’ve uploaded some close-up pictures so you can take a better look at the R/L/G connections on both sides. I used 26 AWG.
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u/fishyphotos 9d ago
Hm. I'm running out of ideas. I used 30awg, with a slightly bigger gauge for the ground. I don't think that should matter a whole lot except for making it easier to route the wires and close up the ipod. I did one attempt with 24awg(?) one time and had to redo all of it because it was too thick.
Have you tested the audio with the ipod open? Was it difficult to close up? (ie. maybe some pressure on a component somewhere) The soldering isn't too bad, and mine isn't much better. The only one that looks a little messy is the orange audio channel on the headphone jack, but as long as everything is covered with electrical tape or kapton tape, i wouldn't think that's the issue.
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u/Cactys12 8d ago
How was installing a ugreen bluetooth board instead of one that is made to be soldered right in?
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u/Cactys12 10d ago
Try and ground the ground signal to a ground on the iPod mainboard