I have tested my link cables and GC adapters very thoroughly and I have
bad news! Here is what we are looking at:
......
"Joytech GBA SP Earphone Adapter with stereo earphones. Enjoy Dynamic stereo sound from your GBA SP."...
Headphone Adapter test
What a tragedy. The adapter works with my real GBA SP in all cases. With the K1 GBA anytime the adapter is used outside the MP3 viewing screen the screen goes black and a loud buzzing noise is produced over the headphones. If the system is on any menu or a game is playing, if you plug in the headphone adapter the screen will go black. If headphones or speaker s are connected you will hear a bit of the desired audio in a
huge mess of distorted sound and buzzing.
If you are listening to an MP3 with the device and then plug in the adapter, it works as intended. You can listen to one MP3 with the device just fine but anything beyond that will produce horrible results.
The saddest part is that this is obviously a software problem that wasn't tested. It is probably not a hardware issue for my unit.