Sega Genesis replacement resistor

Ok so I was too tired when I started installing the mega amp and accidentally removed the wrong resistor, R21, marked 513 so a 51K resistor. Of course I can 't find that tiny thing and need to replace it. I have 47K and 56K and measured one to 54.9. Is that close enough or is precision important here? I have no idea what function that part has...

I should add that it's a va7 board

 

A VA7? If it's a model 1 VA7....


In all seriousness, try to find one online that has the exact rating you need.

 

Thanks for replying. Heh, well that's the reason I'm installing the MegaAmp.

The resistor turned out to be part of the circuit that I'm replacing so no harm done.
Guess I was too tired to think at all yesterday.

Anyway, it's installed and sounds great! Can't decide whether I prefer filtered or unfiltered...

 

Glad to hear it's working now! I don't like the VA7 since it's secretly a Model 2 in disguise. It doesn't support the Sega Mega Net modem from Japan, the region mods require more parts, and they moved the I/O ports on the back for no reason. On top of that, the mobo is uglier. Also, people confuse the VA6.5 and VA6.8 non-HD model 1s for the VA7 when they are actually just as good as a VA6.

How does it sound now compared to the stock audio of the older VA3s-VA6.8s?

 

Ok, those are all points I haven't considered. Especially not the ugliness of the motherboard. I have no real sense of aesthetics when it comes to that.

I haven't made a direct comparison, but with filtering enabled it sounds pretty close to how I remember the original model 1's. In any case it's a vast improvement.

 

I don't really care about the look of the motherboard either lol. The VA7 used to be the worst model of the Genesis/Mega Drive. Ever since the Mega Amp came out, it became just as good as the good model 2s. Not many people use the modem so it's not a huge loss lol. It's also quite rare and expensive. If you want to play like 1 game over a phone line, there's the earlier model 1s for that lol.

About the comparison, that's awesome! I was going to get a mega amp for a model 2 once I get around to buying one but I might get a mega amp for my model 1 VA6.5 too. If you have an everdrive or other flash cart for the MD/Genesis, there is a file on the web that tests the sound chip to its max limits. I saw MN12BIRD's video on it on YT. He tested it on an early model 1 and it sounded like the song was being played on the Sega CD. If you can, try that file on it.

 

MegaAMP is not needed for older model 1's, you can change the preamp resistors and smd ceramic caps to achieve similar output.

 

Ah ok. Do you have a guide for it?

 

It's different for each model but there is a thread on Sega-16 on it.

http://www.sega-16.com/forum/showthread.php?27397-VA2-Preamp-fix

 

I think the model 1 is ugly as is, I personally much prefer the sleeker aesthetic of the model 2. Also, every single model 1 I have come across has suffered with jail bars that couldn't be fixed by lifting pin 50 of the VDP. This is exactly the reason I use a model 2 with a mega amp, as it's much easier and more reliable to get a model 2 and fix the sound, rather than get a model 1 and fix the video.

 

Haven't noticed any jailbars on the VA7, but that may be because it's essentially a model 2 hardware-wise then. So if you prefer the model 1 design, a va7+megaamp may actually be the best setup then.

 

Thanks for the tip! I'll definitely try that sound test rom.

 

You haven't seen a VA6-VA6.8 board then. They don't have rainbow banding or jailbars with a high quality RGBS cable. The 32X also fixes this for composite video if you don't want to use RGBS for some strange reason.

 

I disagree. I've had two VA6.8s, both of them had jailbars, even with really high quality cables. In my opinion, model 1s just aren't worth messing with; just get a model 2 and a Mega Amp and it sounds better than a model 1 anyway.

 

I probably haven't seen them on my VA6.5 because I have a high quality RGB SCART cable with extra components that eliminate them and boost the sync signal. I also don't see them via composite but RF does show them. The only mods done to mine are the two region mod switches. I should also add that my cable is for a model 2 and I'm using a 32X. I'm going to be wiring a RGBS to YPbPr converter to a custom cable that plugs into the Model 1's AV port. I'll let you know if I see jailbars or not.

I prefer the model 1 because it has the most features. A VA0-VA6 (HD Model 1s) has a 9 pin port for the official Sega Mega Net modem. VA6.5s and VA6.8s (Non-HD Model 1s) still have circuitry but lack the 9 pin connector. VA7s and the model 2s lack modem support entirely. The modem is also still usable (it's direct dial) today but only when the supported games are played in Japanese mode.

 

Hold up. The region mod on the VA7 requires more parts? Do you know what parts these are? I've been looking into region modding my VA7, but I read that people struggle with 50Hz PAL on the VA7. I haven't found a solution either to this problem...but maybe it sounds like it needs those "extra parts?"