GBA speaker noise fixed!

Discussion in 'GBA - Hardware, Devices and Utilities' started by malheur, Nov 22, 2016.

  1. RemixDeluxe

    RemixDeluxe GBAtemp Psycho!

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    Nov 23, 2010
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    No way I don't believe that. You can even get better quality just from plugging directly into the headphone jack. It's not the same as the speakers. Compare it with any GBA game music.
     
  2. Peeteris

    Peeteris Member

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    Mar 7, 2017
    Can someone give more information about this? I am really interested in making my GBA way louder or at least just louder.

    — Posts automatically merged - Please don't double post! —

    Believe me. I changed original speaker to decent quality new one and sound now is too crisp that it sounds irritating and tiny. Original one gives out a bit muffled sound but in this case it's a positive aspect.
     
    Dnilo and RemixDeluxe like this.
  3. Z80

    Z80 Member

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    Jun 10, 2017
    Going to add a 16V220uF nichikon fineGOLD I had lying around from a dead high end mobo, maybe too overkill for a gba? Btw does someone know how much loud is the original GBA sound when maxed out? I think mine is quieter (at least is quieter than mi AGS001 ) I dont know what could be the cause or what to check, could it be the volume resistor? it barely offers any resistance to movement when lowering and maxing the volume I cant remember if it used to offer more resistance to movement when the gba was new.

    I changed the original speaker because of that for a new one similar to those offered with the gbAMP, i didnt notice the sound to be any crispier but I still think it has a low volume when playing with the mono speaker alone.
     
    Last edited by Z80, Jun 15, 2017
  4. Z80

    Z80 Member

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    Jun 10, 2017
    Well did it, it was a nightmare to get that cap inside of the GBA casing, only very very few noise remains almost unperceptible when using headphones but bass is pumped up lol? Shoots on Metroid Fusion are crisper and the music is more brilliant, like when playing in GBA player /w swiss, i think I burned a lil bit one of the wires of the speaker when approaching the soldering iron and now the speaker doesnt play sound, ill check that tomorrow (I shouldnt work at 5 am xDD, but I wanted to finish it).

    Maybe I could triy to add another 100uf capacitor in parallel.
     
    geyser likes this.
  5. lostdotfish

    lostdotfish Advanced Member

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    Feb 13, 2016
    Just added a random 100uf 25v cap I had lying around to my GBA and it's nicely soaking up that noise. Thank you for sharing your fix.

    I was thinking about the possibility of doing a stereo speaker mod to one of my GBAs. @malheur - any thoughts on if this would be possible? I guess the stereo channels aren't broken out on the motherboard (except on the headphone jack) but couldn't we tap straight from the DAC?

    The 2 challenges:

    Find somewhere to tap the left and right channels.
    Find a way to retain the headphone muting of the speakers when connected.

    Not sure if we can achieve the second challenge without engineering an add in amp (like the GBAmp3).

    Couldn't we tap L&R from the volume pot?
     
    Last edited by lostdotfish, Jul 14, 2017
  6. malheur
    OP

    malheur Advanced Member

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    Oct 11, 2016
    when you modding the component, easist way to start is read a datasheet. thats the problem. cant find anywhere datasheet of AMP AGB. so if you want to do something with it you have to try and error.

    so far what i know is, stereo signal only out from the headphone outlet without amped, and the muting is also processed by amp chip, not the extra switch thingy. included volume also works with single channel.

    i think its impossible with using only included components. but nowadays theres many solutions for tiny amp and the Arduino can do almost every job. since GBA has reletively large enough room and support enough power for put things, ATtiny may help mod what you want.

    ---

    ps : i found tiny 3W amp chip named PAM8403. its stereo tiny amp chip working on 2.5-5.5V. theres regulated 3.3V power on GBA board, 3W out is good enough(actually over spec), small enough to put in the GBA, and its cheap. if you make headphone bypass switch, i guess it is possible to put stereo speaker in GBA.
     
    Last edited by malheur, Jul 15, 2017
  7. alcx

    alcx Newbie

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    Mar 11, 2018
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    Thanks for this fix, worked for me.

    Before the fix, I found that powering the GBA from old batteries made the noise louder and good batteries made it less noticeable, so it could be that the DC-DC is working a bit harder resulting in more noise.

    Pin 9 of the AMP is the Voltage reference pin, you can check the other pins from the GBA service manual.
    Before the fix, I tried testing caps on the LPF side of the AMP, but I don't think it's really a low pass filter for the audio, it seems like it might be to adjust the volume coming from the MCU, it made some difference but the volume was reduced so your fix works better.
     
    Last edited by alcx, Mar 11, 2018
  8. steocullen91

    steocullen91 GBAtemp Regular

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    Jan 29, 2017
    Ireland
    You know what, every gameboy I've ever owned has done this. I decided to check the original GBA advance that I backlit modded and very surprisingly it doesn't buzz at all. Not through the speakers or headphones at all. I always just lived with it but that's kind of odd how I seen this thread then checked mine and it just happens to be silent. Maybe the used different components in some models. Mines a 40 pin GBA if that makes a difference.
     
  9. rigoriga

    rigoriga Newbie

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    Jan 31, 2016
    United States
    I modded my own GBA recently, and I used a gold Nichicon 16V 100uf I had from a SNES project and I managed to get rid of the buzzing. But I now hear a high pitch whine from the system. Should I move up to a 220uf cap? I also read a guide on those chiptuner guys on using foil, but I soldered a wire from the bottom of the speaker to ground, and the problem persists. I am using a 40 pin GBA screen, but it was not a type B with a wire so I instead soldered a point near pin 103 of the GBA CPU to ground (which only fixed the ghosting issue). Or will actually getting a type B adapter fix most of my problems?

    Edit. Well I did the remove parts mod as recommended. Bridging the two points was a pain mostly because I used a 1 inch piece of wire instead of a three like in that picture. The whine from the voltage regulator is more quiet, so quiet that I can hear the buzz from the speaker (which goes away after a few seconds).
     
    Last edited by rigoriga, Mar 31, 2018
    Home_Rowed likes this.
  10. isoboy

    isoboy GBAtemp Advanced Fan

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    Dec 23, 2016
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    I just did this mod. I felt very confident as I've modded a lot of stuff before. First thing I do is bridge the first two pins. I don't have proper solder removal stuff and I struggled somewhat using both a razorblade and the solder iron to separate the pins. In the end it worked.
     
  11. Dnilo

    Dnilo Member

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    Dec 3, 2013
    Mexico
    Thank you SO MUCH, just did the mod using a 220uf 25v capacitor (after testing a 100uf25v) and I'm super happy without that 'humm', I didn't notice much difference from the 100 to the 220, and placebo effect might have gotten into my ears feeling the 220 with a tiny bit more bass as Z80 here mentioned.

    Enjoying another play through Aria of Sorrow.

    I can confirm the original speaker having better sound than others, I have built several AGB-101 mods in the past and while doing so I added an "improved" speaker to one of them, then I tested the same game running at the same time with both mine (original speaker) and the "improved one", one in each ear.

    Again, thank you. Now my AGB-101 is perfect.
     
  12. Flexis

    Flexis Newbie

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    Jan 7, 2019
    Belgium
    *
     
    Last edited by Flexis, Jan 7, 2019
  13. Galaga_

    Galaga_ Newbie

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    Dec 28, 2018
    Uruguay
    Hey guys, so I made this mod both with a 100uf 16v cap and a 220uf 16v cap and I still have the buzzing and noise both on the speaker and trough my headphones.
    Any ideas on what the problem could be?
     
  14. phreak97

    phreak97 Member

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    May 2, 2009
    Australia
    Adelaide
    Great work fixing the hum!

    Is there an equivalent mod for a gba with the Mitsumi PM B3 amp?

    Like the AGB AMP google has no information to share on pinouts.

    Thanks!
     
    Sterophonick likes this.
  15. Hammyface

    Hammyface GBAtemp Advanced Fan

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    Jun 4, 2006
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    I am trying to do this fix but I only have 220uF 6v, not 16. Is a 6v capacitor OK? Or is it too "low" of a voltage?
     
  16. emuman100

    emuman100 GBAtemp Regular

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    May 12, 2006
    United States
    Has anyone tried replacing the electrolytics on the motherboard with new ones? That hiss is probably the DC to DC converter, and if the electrolytic becomes noisy or leaky, the hiss might be at a high enough level to be noticeable.
     
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