weak MegaDrive/Genesis audio after stereo mod

Video Games
1

Hi, I have an megadrive/genesis I bought as I am an enthusiast of the SMS music and the megadrive would allow me to benefit also of the 16 bit console audio chip.

I bought the excellent retrotink 2x-pro to upscale it’s RGB signal and did the audio mod (Genesis 1 Stereo Audio Mod | RetroRGB) to enjoy nice stereo music. I also got an everdrive X5 to put all those .VGM music in there. I’m very glad this project went well.

Only problem now, the audio is very weak and I would like to bring it to a more normal level without cranking up so much the receiver level. I see there is way to bring back that headphone amplifier level by doing further mod, but I’m not sure it’s worth it and I like that idea here of using an internal amplifier : Reddit - The heart of the internet . I think there might be good small pcboard that would accept 5v level that is readily available from the power supply. I was wondering if people have recommendation on a good, yet cheap and small amplifier I could use internaly. Maybe something similar to https://www.aliexpress.com/item/1005008059201648.html but I would need help to select transistor and make sure level are in good range.

Thank you

2

In case someone wonder how I did it. This is where I tapped the stereo signal https://junkskool.net/images/photos/Computer_stuff/genesis_megadrive_stereo_audio_out_mod.JPG
Then I got an AD828 based preamp. It support 5v to 15v +/- 2.5v but really start to work well at 5v but it’s borderline. I found it preferable to use the 9v line. It fit perfectly on the next area of the genesis/megadrive https://junkskool.net/images/photos/Computer_stuff/genesis_ad828_pcboard.jpg
I wanted to have it switched on/off with the console so I tap the 9v before the 5v regulator in between the Switch and the D1 or D3 diode https://junkskool.net/images/photos/Computer_stuff/ad828_d3_diode_internal_switched_preamp.jpg The ground is on the breakout pcboard power barrel connector. Notice the barrel is + and interior is -. Now the audio is at a good level :musical_notes: :partying_face:

3

Hi, no idea but basically if it’s weak/too quiet then it’s the amplifier not, well, amplifying enough. So sounds like you got enough voltage in there now to get it amplified to a useable level?

4

Hi D.Lo, the difficulty with the stereo mod I pasted is that it tap the signal before the mono pre-amplifier, making it very faint then. A solution I saw is to use the earphones amplifier that is stereo, but that might be too powerfull for a line-level signal and I assumed it to be of rather cheap quality.

That’s why I brought back that signal to a line-level using an AD828 pre-amplifier. The signal level work very well now, the sound from the console is what an amplifier would expect and the receiver can now amplify it normally, no need to crank it to dangerously high level to hear it clearly. Thank you for your concern, but I’m very happy with that solution now and just shared it here in the hope to help someone in that situation as I found others experienced that same situation when I initially searched about it.