MVS: no sound

V3rtigo · Feb 11, 2009

i had extremely low sound (yes, the volume slider was all the way up) coming out of the speakers. headphones worked perfectly. i "upgraded" the speakers to a set of Sony 5.25" 35W 4ohm speakers. now there's no sound out of the speakers at all, and the headphones don't work at all.

so...
is there a separate power supply for the sound that i blew?
any ideas?

Neo Alec · Feb 11, 2009

Check if your power supply is outputting 12v.

Xian Xi · Feb 11, 2009

You should be using 8ohm speakers as 4 ohm will put additional strain on the PSU. If you have 8 ohm speakers lying around test with those.

skeach101 · Feb 12, 2009

hey. I'm new here (first post), but the hell, I'll help out

I just pulled out the ol' MVS manual

The proper speakers are 4" Diameter 8 Ohm 5 Watts

These right here

http://www.therealbobroberts.net/parts.html#hardware

Bob Roberts sells them for $2.50 each.

If that doesn't work, check the 12v like the other guy said.... I'm still learning how to do voltage stuff, so that's beyond me.

ttooddddyy · Feb 12, 2009

The nominal output impeadance, read resistance (for the HA13001) is 4 ohms. MVS boards will quite happily run into 4 or 8 ohm speakers. Arcade psus have enough current available to supply. It does not matter for practical purposes with this application.

The audio output device is designed to drive 4 ohm speakers, running into 8 ohm speakers will do no harm, they will just be a little bit "quieter"

4 ohm speakers are perfectly OK in a mvs cab.

Application/data sheet here http://www.datasheet4u.com/download.php?id=527113

Notice the speaker load. resistive load (RL) is 4 ohms not 8 ohms.

P.S. 2 ohm speakers (or two 4 ohms in parallel) would not be a good idea, that is good for high power rock band stage apps.

A consideration is the max 12 volts supply current to the audio output IC, if running at full volume (with 12 volts at say 1 amp max) you may be pushing the envelope, but who runs cabs at max volume ? For regular use either 4 or 8 speakers are OK imho, given a regular arcade power supply.

A 16 ohm speaker(s) would also work fine.

MKL · Feb 12, 2009

A lot of jamma amps are rated 4ohm. Note that the the HA13001 is not only found on MVS but also on CPS1 (among others). CPS2 is also 4ohm.

ttooddddyy · Feb 12, 2009

Many arcade boardset common audio output ICs (HA,LA,TA,STK etc) are also used in car radio/cassette/CD players where 4 ohms is standard.

channelmaniac · Feb 12, 2009

Cap it.

Low audio levels are an indication that the system is having cap issues. No audio shortly afterwards tells me that they finally failed the rest of the way.

If you need a cap kit, I just assembled a bunch of kits for the 4 and 6 slot boards and updated the site this morning.

RJ

(Yes, I know it's a shameless plug, but it's what he needs)

V3rtigo · Feb 12, 2009

order placed. i hope that works. crazy fighting games with no sound suck.

channelmaniac · Feb 12, 2009

Just watch out for those pesky 22uf and 100uf caps. The ground legs on those require a LOT of heat to desolder. Don't pull a trace or pad when you desolder them.

RJ

Xian Xi · Feb 12, 2009

Good info in this thread yo.

Hewitson · Feb 12, 2009

Xian Xi said:
You should be using 8ohm speakers as 4 ohm will put additional strain on the PSU. If you have 8 ohm speakers lying around test with those.

No it won't. The HA13001 is designed to be used with 4 ohm speakers. Using speakers of incorrect impedance will put additional strain on the power amplifier on the PCB, not the power supply.

Xian Xi · Feb 12, 2009

It could if your PSU has a low max continuous wattage output. Assuming he has a proper PSU then it shouldn't but in this day and age of crap PSUs out there it's not something to not think about.

channelmaniac · Feb 13, 2009

Lower resistance/impedance loads on the amp requires more current to drive... which means pulling more current from the power supply.

Hewitson · Feb 13, 2009

There would be a VERY slight increase in current, however the increase in impedance you are loading the amp with is quite significant and could potentially do damage to some amplifiers.

Jag-Master · Feb 13, 2009

I smell STICKY THREAD Definitely a much talked about issue. I second great info, thanks guys.

V3rtigo · Feb 13, 2009

I'll post up some results when I get the audio cap kit in with the new speakers. The 5.25 inch speakers are a great fit and easy install (5 minutes with a jigsaw) and I would love some better sound than the stock paper cone speakers.

BTD · Feb 13, 2009

I don't mean to thread jack, but I have a similar question. The audio on my CMVS is REALLY low. I've done both sound mods for the MV-2f board and am not sure what the problem is. I'm thinking of putting the audio amp back on. Would that fix the problem?

Xian Xi · Feb 13, 2009

What sound mod did you do exactly? Did you follow MKL's instructions?

BTD · Feb 13, 2009

This part http://i3.photobucket.com/albums/y85/k1ngbuzzo/neo geo/audio.jpg

and the part where you remove the 3-pin amp. I'm pulling the audio from the bottom of the board. (right under the headphone out)

Edit- also this one http://i3.photobucket.com/albums/y85/k1ngbuzzo/neo geo/audiotrace.jpg

Xian Xi · Feb 13, 2009

Any you bridged it with that cap on the trace right?

Hewitson · Feb 13, 2009

I had exactly the same problem following those instructions on my MV-4F. All caps are brand spanking new.

BTD · Feb 13, 2009

Xian Xi said:
Any you bridged it with that cap on the trace right?

I'm not exactly sure what you mean. Are you saying where i scraped off the trace if i bridged the small gap with some solder, then yes.

MKL · Feb 13, 2009

BTD said:
I don't mean to thread jack, but I have a similar question. The audio on my CMVS is REALLY low. I've done both sound mods for the MV-2f board and am not sure what the problem is. I'm thinking of putting the audio amp back on. Would that fix the problem?

BTD said:
This part http://i3.photobucket.com/albums/y85/k1ngbuzzo/neo geo/audio.jpg

Why are you doing that? I've never recommended it. It was just for Hewitson who is obsessed with the idea that the headphones out will blow his receiver, something that in fact would never happen. He came back to me again on this a few days ago:

http://www.neo-geo.com/forums/showpost.php?p=2666279&postcount=5

and as I say it's normal that the sound is low if you tap it from those points: that's what you get for not wanting the headphones amplification (which is perfectly fine).

My advice? Just use the standard headphones out.

As for the other mod, it isn't a sound mod, it simply allows to power the whole board with only 5v.

edit: heck, even the AES mono output from the A/V port isn't line level but is slightly amplified (with transistor on the 1st revision and with an additional op-amp on later revisions).

Heinz · Feb 13, 2009

I had a similar issue last night. Had a mate over, we hooked up my MVS and used the sound from the headphone jack. Ive had sound in the past but it didnt matter what I did, reseated the cart, added more voltage, turned up the volume.

Weird thing is, the audio in the MVS sound test works but no sound during the game? Why now? I had sound 6 months ago when I turned it on last. Im thinking maybe the contacts are fucked as I had a few troubles with GFX Garbage on the screen.

Also garbled green screen before the game loads the NEO GEO screen? Is this an indication of too much or too low voltage?

Sorry to sort of derail the thread, but thought I'd ask.

MVS: no sound

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