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Capcom ZN-2 Stereo output

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sammargh

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So I wired up a 4pin to the external audio connector and didn't have any audio. For some reason I have to unplug & replug the cables for it to be detected which makes it work fine. I'm without a line out converter so I have the amp turned to near-mute which lets it play fine for now but I notice a HUGE power draw once stereo is picked up. At start up/JAMMA audio my Supergun reads 5.03V pretty consistently and with each external channel plugged in the voltage goes down by .03V.

That's fine and all however the heatsink for what I assume is for the audio amp gets extremely hot while running in this fashion and I'm worried that there's something wrong in the setup which could be damaging the ZN-2 A board. When using JAMMA audio the heatsink remains completely cool to the touch even after a long session. Is it normal for the heatsink/power draw I'm witnessing or should I just stick to mono audio? I'm only playing TGM1 so stereo isn't a huge deal but it would be neat to have.
 
I've used stereo via the JAMMA edge on my G-NET as well as a Taito FX-1A PCB that I've got. Recently picked up a ZN2 and noticed that the audio is setup differently. There are also stereo/mono settings in the system menu in addition to the external switch.

according to the manual: http://pdf.textfiles.com/manuals/ARCADE/S-Z/Street Fighter EX 2 [Operator%27s]%20[English].pdf

you'll want to make sure the audio switch is set to "stereo"
you'll also want to make sure the the audio is set to "stereo" in the system configuration (in test mode)

then make sure the stereo connector is wired like this:
Left +
Left -
Right -
Right +

so the positive leads are on the outside and the negative leads are in the center

Generally speaking you'll also want to ensure that there is nothing attached to the audio pins on the JAMMA harness when using the aux audio connector.
 
I guess I can try taping the audio pins and see if that helps but I did wire the connector up per the tech romancer manual. The part I’m worried about is how hot the heatsink on the audio amp gets when stereo is picked up.
 
sammargh said:
The part I’m worried about is how hot the heatsink on the audio amp gets when stereo is picked up.
Click to expand...
That's not normal, and that to me says that whatever you're hooking it up to is putting an unnecessary load on the amp. this often means something isn't wired right.
 
I checked the connector I crimped with a multimeter and the center pin is on the outside pins while the sleeve are the two middle pins. There’s also no bridging from what I could tell so I’m at a loss.

The pins are easily traced back to the amp so I may just solder a header to the line level and see if that improves things.
 
Tried taping over the jamma audio pins but problem still remains :(
 
and you do have both the switche and settings set to stereo?

Another thing to check is broken or cold solder joints around the amp and heatsync. Of its not making good contact it could be putting undue load on it.
 
Yeah, I just had a random thought that the TV's audio input probably isn't a real speaker impedance which is likely the cause. I have some spare speakers laying about so I'm going to try wiring them up and see what happens. I imagine the re-plugging is the the board refusing stereo because of this and I'm just getting around the protection.

Edit: confirmed, this is exactly what's going on. Using speakers the cable works as expected and no replugging/insane power draw happens.
 
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Ended up grabbing a line out converter from Best Buy and wired it up. Everything appears to be working properly now and the power drain is gone and stereo sound is working through my tv :)

https://www.bestbuy.com/site/metra-two-channel-line-output-converter-black/1265702.p?skuId=1265702

If someone happens to come across this in the future you just need to wire the +- wires up to right & left, ground can be left floating. The ground wires are to assist with ground loops but I don't seem to notice any through the ZN-2.
 
So if I wanted unamplified left and right channels is it just a matter of tapping the inputs that go to pins 2 and 7 on the LA4705N, or am I missing something? There's two input capacitors (C313 & C314) between the amp and the volume pot. If I wanted to retain some volume adjustment functionality, can I just tap the audio after the pot?
 
Possibly, I had thought about looking into that however I am not a big fan of soldering to arcade boards unless it's to fix something broken on them so I haven't looked very far into it on ZN-2.
 
I would probably desolder the pot, lift the two legs in question and tap the signals from there. That way it can be pretty easily returned to stock. I'll update if I ever get around to it.
 
Well, I did it. It works fine?

I was hoping it would sound better, but I guess it's still an improvement over the original amp. I'm using the amp in the Blast City.
 
I'll just throw this in here in case someone decides to search and gets really bored like I did today. I don't feel like it deserves its own thread and there's no ZN-2 sub forum so whatever.



Tetris: the Grand Master for the ZN-2 while it only came out in Japan actually has regions built into the game!

cjwYxa0.png


4nMR15W.png




If you look at the cutting room page for TGM you will see there were a lot of english strings as well as some unused art. Turns out switching to US will enable the "DON'T USE DRUGS" screen and likely those unused backgrounds were used as a means to censor between regions (for example one level has a fetus as a background) however the last part I can't verify because I'm not good enough to beat the game.



Anyways super easy to convert the region, you need a 27C4096 and the TGMJ rom set from mame. Grab atej_04.2h from the set and go to the very, very end of the rom. The very last byte 0x7FFFF is the region code and is set to 00. The following codes are regions that will work with the game:

Code: 
00: Japan
01: USA
02: Asia
03: Europe
04: Hispanic
05: Brazil
06: Nigata
07: Odawara
08: Pub Ver (Causes game to crash at first boot screen)


Once set write the chip and replace the one in your pcb with the sticker 04 on it.
 
this is useful stuff! I'm totally going to flip mine to USA. No need to bury it in a thread... I think it deserves its own post for sure.
 
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