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kuze

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Anyone on this board have a Gunbird 2 PCB?

If so can you snap a picture of capacitor 1 (C1) next to the rom marked "SOUND" for me, or provide the value?

I noticed mine appears to have been snapped off before I received the board.
 
Thanks @rewrite!

Just out of curiosity is your Gunbird 2 PCB "noisy" with video interference in the sound? It's not as noticeable in game, but definitely so during attract mode.

It seems to be a common problem others have faced including myself:
http://www.neo-geo.com/forums/showthread.php?192077-Gunbird-2-Sound-Issues

Pretty sure I've got a 25v 100uF cap I can throw in to C1 to see if it makes a difference.

(FWIW I've already replaced all other caps, didn't notice C1 was missing)
 
Just out of curiosity is your Gunbird 2 PCB "noisy" with video interference in the sound? It's not as noticeable in game, but definitely so during attract mode.
I'll have to take a closer look. I'd picked it up broken and fixed it thanks to some advice from @Mitsurugi-w. I didn't even know which Psikyo game it was until I plugged it in and it worked!

But really, I fixed it, then let it run in the cab a while, and haven't turned it on since. I'll try and have a look today.
 
I added the 25v 100uF cap to C1 and it didn't make any sort of noticeable difference unfortunately. ;(

If you turn the volume pot almost all the way down on the PCB and compensate externally (e.g. supergun -> line level -> amped via another system), it's not really noticeable.

But playing it as-is on something like the Egret 2 where you rely fully on the PCB's amp, it's pretty awful.

Seems like possibly a good candidate for a line out audio mod, but then again wouldn't help something like the E2 (without another amp).
 
@kuze I'm about to recap mine with some high grade audio caps. If that doesn't improve things I may do a line-out mod, or goof around with some of the caps that are not populated on Gunbird but are on Strikers 1999. I'll keep you posted.
Nice, I'm definitely interested to hear how it goes!
 
I replaced C22 and C19 with 104K caps that were used everywhere else. That made a large difference to me. I also installed a C0805,100pF±5% 50V C0G on C12. Possibly it’s also necessary but perhaps not, I’d change this last. I took off my C12 and damaged it while trying to take its value, so I don’t actually know what should be on here. Looking at the data sheets for the nearby chips, I took a guess. If anyone can pull and check their C12 please post.

Would be nice if someone with a little EE could take a look at this circuit, I’m almost positive there’s just an error somewhere.

good luck fellas! If anyone gets it perfect lemme know. This is certainly much improved to my ears.
 
I replaced C22 and C19 with 104K caps that were used everywhere else. That made a large difference to me. I also installed a C0805,100pF±5% 50V C0G on C12. Possibly it’s also necessary but perhaps not, I’d change this last. I took off my C12 and damaged it while trying to take its value, so I don’t actually know what should be on here. Looking at the data sheets for the nearby chips, I took a guess. If anyone can pull and check their C12 please post.

Would be nice if someone with a little EE could take a look at this circuit, I’m almost positive there’s just an error somewhere.

good luck fellas! If anyone gets it perfect lemme know. This is certainly much improved to my ears.
I posted a list of caps on mine when I recapped, but now I can't find the thread.

@acblunden2 had started the cap kit thread I believe? Maybe he has a link

Of course I can't find my notes except my digikey order which has a bunch of M84 caps on there too lol
 
@kuze Oh I made a cap list too; this fix is swapping values entirely, both were 222k film to start. and the one I broke was an 0805 ceramic smd I’m sure nobody replaced or measured.
 
@kuze Oh I made a cap list too; this fix is swapping values entirely, both were 222k film to start. and the one I broke was an 0805 ceramic smd I’m sure nobody replaced or measured.
Ahh got ya, yeah I only replaced all electrolytics on mine - no SMD caps. I bet you're on to something!
 
@kuze Oh I made a cap list too; this fix is swapping values entirely, both were 222k film to start. and the one I broke was an 0805 ceramic smd I’m sure nobody replaced or measured.
Ahh got ya, yeah I only replaced all electrolytics on mine - no SMD caps. I bet you're on to something!
Me too... I'll start a new thread for this once I gather some photos so maybe some other folks can take a swing at it.

edit: made thread Gunbird 2 Audio Improvement [WIP, help wanted]
 
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