F/S Mega AMP for Sega Genesis

[cleeg]

I have an MD2 on the way (PAL), the motherboard type of which I am unsure right now, but was thinking I must have the audio fixed and came across this thread last night, it must be fate!

Which sounds the most authentic, filtered or unfiltered? I'd like to order the one that sounds most like an original model. Still have any available?
One more quick question, will wire scavenged from a SCART cable be sufficient to solder this board in? Or do I need a particular gauge / type for best results.

Cheers, and lovely mod job.

[FuturePrimitive]

Sweet! I've been meaning to get a couple Mega Amps for my Genesis Model 2 and Genesis Model 3 VA1. Do you have a GOAC YM3438 Mega Amp for the Genesis 3? I can't find specific wiring instructions for adding the Mega Amp either.

[Helder]

I have an MD2 on the way (PAL), the motherboard type of which I am unsure of right now, but was thinking I must have the audio fixed and came across this thread last night, it must be fate!

Which sounds the most authentic, filtered or unfiltered? I'd like to order the one that sounds most like an original model. Still have any available?
One more quick question, will wire scavenged from a SCART cable be sufficient to solder this board in? Or do I need a particular gauge / type for best results.

Cheers, and lovely mod job.

A Scart cable should have more than enough wires and I guess filtered has the sound closest to the original but this new model has switches so you can choose which you like.

Sweet! I've been meaning to get a couple Mega Amps for my Genesis Model 2 and Genesis Model 3 VA1. Do you have a GOAC YM3438 Mega Amp for the Genesis 3? I can't find specific wiring instructions for adding the Mega Amp either.

I do have the Goac and here are the install images:

[cleeg]

Cool, thanks for that speedy reply. I'll be in touch with my mobo details when I have them. I imagine I could use a latching ON-OFF single throw push button with two pins to control the sound mode?

[FuturePrimitive]

Thanks for the response! Do you think this Genesis 3 Mega Amp mod could be done by a beginner at soldering? I have a basic soldering kit.

I have some beginner questions on the install images: 1. First image... Can I use any sharp knife to cut the trace leading to Audio Mono? Is it required to wire Audio Mono to the Mega Amp?

2. First and second image... I see two solder points for Audio Right and three solder points for SN76489, do I solder two wires for Audio Right and three wires for SN76489 on the motherboard to the single solder points for Audio Right and SN76489 on the Mega Amp respectively?

3. Would it be ok to use a Soldapullt desoldering pump to help remove these small components? Is there a certain temperature to set the soldering iron at for desoldering?

4. Are there any unique instructions about the 32X?

5. Do you just let the Mega Amp sit in an open space on top of the components on the motherboard, or do you elevate it somehow?

6. Where do I wire 5V and GND on the Genesis 3 VA1?

Thanks for any help.

[ComradeOj]

@FuturePrimitive
I can answer some of these.

5. I put mine on top of the main ASIC in my model 2. I put a small piece of RF shielding wrapped in electrical tape between it and the MegaAmp to make sure there was no interference. I don't even know if that's necessary though.

6. Look at the bottom left of your VA1's model 3's circuit board. You will see a black component screwed down with three legs sticking out labelled "I", "G", and "O". This is a voltage regulator. The pin marked "O" should be a perfect 5 volts. The G should be ground. Test it with a multimeter to be sure though!

[Helder]

Cool, thanks for that speedy reply. I'll be in touch with my mobo details when I have them. I imagine I could use a latching ON-OFF single throw push button with two pins to control the sound mode?

I'm not sure you have seen the images of the boards on the first post or not but there are already switches on the board to select the filtering but maybe you're talking about putting a switch on the case?

Thanks for the response! Do you think this Genesis 3 Mega Amp mod could be done by a beginner at soldering? I have a basic soldering kit.

I have some beginner questions on the install images: 1. First image... Can I use any sharp knife to cut the trace leading to Audio Mono? Is it required to wire Audio Mono to the Mega Amp?

2. First and second image... I see two solder points for Audio Right and three solder points for SN76489, do I solder two wires for Audio Right and three wires for SN76489 on the motherboard to the single solder points for Audio Right and SN76489 on the Mega Amp respectively?

3. Would it be ok to use a Soldapullt desoldering pump to help remove these small components? Is there a certain temperature to set the soldering iron at for desoldering?

4. Are there any unique instructions about the 32X?

5. Do you just let the Mega Amp sit in an open space on top of the components on the motherboard, or do you elevate it somehow?

6. Where do I wire 5V and GND on the Genesis 3 VA1?

Thanks for any help.

I don't have a model 3 so I can't tell you for certain where 5v and ground are but use a multi meter to probe around. Heating temps should be 350 to 400 degrees Celsius just don't hold it in one spot too long. The 2 points you mentioned you can use either one since they're connected.

[cleeg]

I'm not sure you have seen the images of the boards on the first post or not but there are already switches on the board to select the filtering but maybe you're talking about putting a switch on the case?

No I had not *face palm!*

That's even better, I could just make a nice little mechanical switch to go through the case or similar.

[Helder]

If you want a board without the switches just be sure to leave a comment when you purchase one. There are decent sized pads on there so you can solder some wires for switches.

[cleeg]

Cool, will do. If I do decide add my own switch to the case, I'd do a push button. What type would I need, an ON-ON type, or ON-OFF type? Also (I'm really not very up on the finer points of this type of thing), how many pins would there need to be? I assume two.

[Helder]

If you want to do 2 switches then I guess that would work but my switches are 6 pin on-off-on function so might need something like that.

[cleeg]

I think I'll just keep your switch!

[Ryoandr]

I got my 2 amps, installed 1 in a PAL MD2 VA1 unfiltered ; now it sounds awesome, I'm just waiting for my shielded RGB cable and it'll finally be worthy.

Thanks a whole bunch Helder, these are really nice boards. I might come back for more.

[Helder]

Thanks and I'm glad they got there fast too, I have plenty of this design so no worries of running out anytime soon.

I added a video to the first post that has a great example of the Mega AMP in action.

[BoostedGR33K]

Just ordered my 1st board.... Cant wait! -Ben