Asura Blade & Sengoku Blade - No audio on supergun

[KmanSweden]

What's up with these boards?

[Hewitson]

IIRC, I've read somewhere that the ordinary GND is better (more compatible) to use for superguns than Speaker-, however I have no written documentation to back this up.

Never use the speaker - as a ground. Many arcade boards use what is known as a complementary symmetry amplifier which means speaker - is speaker + inverted, not ground.

Look at this example from the HA13001 used in the Neo Geo and many others. You will see there is an amplifier connected to BOTH speaker terminals.

[dbstallman]

can you confirm please? Cheers

I just took a photo of the Asura Blade pcb before I went to work this morning. There is a trace, but it goes to nowhere...

No.... It goes to a via and then pops up on the component side of the board. You need to turn the board over and then follow the trace from there.

You will probably find that it goes to an amp just like the trace on the Sengoku Ace board does.

Brian.

[Shou]

Asura Blade is known to have the audio and audio ground mixed up from the factory. You'll need to swap the wiring for it to work.

Not sure why you have an issue with Sengoku Blade.

[meijin]

Asura Blade is known to have the audio and audio ground mixed up from the factory. You'll need to swap the wiring for it to work.

If so, then it shouldn't run correctly in a cab, correct? I don't know, but Asura Blade runs without problems in my Aero/Blast (standard Jamma connector)

[crunchywasp]

Presumably pin L is hooked up on both cabs?

[meijin]

um, I'm not sure at the moment. Let me check it when I'm home

[crunchywasp]

Cheers Bastian

[Rossyra]

can you confirm please? Cheers

I just took a photo of the Asura Blade pcb before I went to work this morning. There is a trace, but it goes to nowhere...




Here is also the photo of the Sengoku Blade pcb (solder side).
http://img692.imageshack.us/img692/2341/dscf2847i.jpg"

Pin 10 is running to a through-hole in that pic. The key counts as a pin, you're looking at pin 11 (if you're forgetting to include the key) which should normally have no connection for standard Jamma.

[meijin]

Presumably pin L is hooked up on both cabs?

It is hooked up on both cabs

Aero


Blast

[crunchywasp]

Thanks for confirming

I know pretty much nothing about speakers Does wiring them up with the polarity reversed cause any major issues? Would the speaker just operate in reverse or something?

As far as the cabs are concerned where speaker + (10) at the JAMMA edge is ultimately hooked up to the + post of the speakers and speaker - (L) to the - post of the speakers then all's well and good...

If reversing the polarity of the speakers is ok, although perhaps not ideal, then if speaker + and - were reversed on the PCB for whatever reason then I'm assuming audio would still work ok?

[emphatic]

Thanks for confirming

I know pretty much nothing about speakers Does wiring them up with the polarity reversed cause any major issues? Would the speaker just operate in reverse or something?

http://www.ehow.com/info_8372487_happen ... wires.html"

Basically, if these games have these pins in reverse, wiring with - and + hooked up to - and + will give sound, even if it's not correct sound. However, if the - is hooked up to GND, well, then the wrongfully hooked up + will go to GND and the - will go to + = no sound.

I think this is the solution, basically.

[crunchywasp]

Thanks emph.

So where the SG with audio via scart to TV speakers is concerned, specifically for boards where speaker + & - are reversed, am I correct in stating that the following must be true in order for audio to function :

• Pin 10 should be GND

• Pin L should be speaker +

...and in the case of these boards where the cabs are concerned :

• Pin 10 should be speaker -

• Pin L should be speaker +

But although the polarity is reversed the audio still works in the cabs, although with errors.

So a switch or pass-through specifically for use with these boards on the SG would be the easiest solution...

[julius blaze]

Just throwing it out there, I've seen power supplies with bad -5v that still have working +5 and +12, so maybe measure if you're actually getting -5 on the rail. It's a long shot, -5V tends to be more of a williams/older american PCB thing but it's just something else to check if you're at a dead end...and would explain why most other games work but these ones have no sound.

[crunchywasp]

Thanks buddy. We've checked the -5v and that wasn't the issue...

As far as I know both games don't require -5v and also I checked the -5v line on the SG and it works. So this is not the problem.

I'm going to build a pass-through as described above this weekend and give that a shot. Fingers crossed that'll do the trick.

[crunchywasp]

Quick update just in case any one else has a similar issue or is remotely interested...

I built a pass-through as described a few posts up and it works grand with Asura Blade but not Sengoku Blade

I'm not entirely sure what's going on with Sengoku Blade

[SEGASHIRO]

I have one these boards and I am not getting audio...I am interested!