I have a strange issue:
I modded a DMG which already had an IPS mod with CleanPower and CleanAmp (both the white versions). I copied this picture https://retrosix.freshdesk.com/support/solutions/articles/77000419543-game-boy-original-cleanamp-v1-1-install-guide . Since then it appears that some sound is missing on the speaker output.
I noticed this in Super Mario Land, as it sounds like the high notes are missing. It is extremly noticable in Tetris 2 as only the background melody and percussion is still there.
Listening through the headphone output or after soldering the speaker back on the front PCB, every track sounds complete.
My uneducated guess is, that the CleanAmp gets an stereo input but outputs one of the channels to the speaker. Or the wiring or one of my soldering points is bad (not unlikely as I am inexperienced). I attached a picture, the speaker is connected to the front PCB right now. I had the solderpoints for loudness connected on the CleanAmp but removed them, which did not bring any improvement.
Are both channels coming from the pins at the sound wheel? Or is only the upper one providing the sound signal?
Is it correct that one of the solder pads of the CleanAmp is not connected to anything? Could it be a faulty chip? I soldered one into a GBA which works fine and have a third one which is intended for another DMG but i could try using it for a test.
Any idea on how to fix this?
Everything looks correct there. We have a new version out soon I can send you a prototype of to output from both channels. Currently it outputs from the right channel and that contains all audio that the left does as far as I have ever noticed.
Email firstname.lastname@example.org with your original order number and details but wait about 3 weeks and then I will have the new dual channel version I can send you to test.
I am out of town right now (hence, only that quick picture), so, no worries. And my newly fully modded GBA even replaced my Switch as travel companion, really loving it.
I will gladly help you out with testing.
Honestly, I wasn't aware that DMG is capable of stereo at all, so, it took me by surprise. I will try to find a game where I can select between Mono and Stereo ingame. Pokemon games for the GBA are able to do that, maybe the originals have that option, too.
Only idea I have: Maybe the IPS mod is triggering stereo audio rendering somehow? I will plug in an unmodded front PCB and solder the sspeaker back on and report if it changes anything.
If you need it, I can upload the produced audio from the same game in different GameBoys as an example on the different sound.
It's no issue, the next batch of PCBs will be stereo capable so I can just send you one of those. Be a few weeks