PCM Sound & Stability Fixes Multicarts - 120 in 1, 138 in 1, 161 in 1 and others.

[GadgetUK]

In summary, the SDRMPX and SDPMPX bypass caps (47pF) make the biggest difference to PCM sound on all these carts, but its worth doing all of the mods imo.

This has fixed sound problems in many games across all the carts below. The 161 in 1 in general suffers less from the PCM issues, but it IS affected. Pulstar is now fixed on my 161 in 1, as well as Puzzle Bobble, and a few other games which had random sound issues.

138 in 1, and 120 in 1
https://www.dropbox.com/s/nx0fhk0eimacrpi/multicartfix.zip?dl=0

This also fixes Pulstar on the 161 in 1 for me as well =D The 161 in 1 needs traces scratching (like the 138 in 1 does). The 120 in 1 seems to have 2 pads for the caps already.
161 in 1 (150 in 1 also?)
https://www.dropbox.com/s/kdf1bd2fqow6xkv/161 in 1.jpg?dl=0

Here's the link to the thread that lead me to the fixes. http://www.neo-geo.com/forums/showt...mp-Board-Slot-Compatibility-regards-PCM-sound I've posted this seperate thread due to the title hopefully being more useful. People might never look into the original thread. Hope someone finds this useful!

 

[mjsaville]

In summary, the SDRMPX and SDPMPX bypass caps (47pF) make the biggest difference to PCM sound on all these carts, but its worth doing all of the mods imo.

This has fixed sound problems in many games across all the carts below. The 161 in 1 in general suffers less from the PCM issues, but it IS affected. Pulstar is now fixed on my 161 in 1, as well as Puzzle Bobble, and a few other games which had random sound issues.

138 in 1, and 120 in 1
https://www.dropbox.com/s/nx0fhk0eimacrpi/multicartfix.zip?dl=0

This also fixes Pulstar on the 161 in 1 for me as well =D The 161 in 1 needs traces scratching (like the 138 in 1 does). The 120 in 1 seems to have 2 pads for the caps already.
161 in 1 (150 in 1 also?)
https://www.dropbox.com/s/kdf1bd2fqow6xkv/161 in 1.jpg?dl=0

Here's the link to the thread that lead me to the fixes. http://www.neo-geo.com/forums/showt...mp-Board-Slot-Compatibility-regards-PCM-sound I've posted this seperate thread due to the title hopefully being more useful. People might never look into the original thread. Hope someone finds this useful!

Your the man... Thanks very much for posting this and persevering with the sound issues. Pulstar on my 161 made me think I had a cap issue on my 1fz and swapped them all. At least I know they are fine now
Anyway, did you know if you google 138 in 1 the top hits are your YouTube videos !

Superb, thanks again.

 

[GadgetUK]

Thanks! Here's the vid:- https://www.youtube.com/watch?v=jwHHIpLcjdE I almost recapped my MVS due to the problem, glad I didn't lol.

What's nice about these fixes is the more games I now test the more things I can hear have been fixed. This all started with NAM-1975 on my 120 in 1 - that was the first game I had wierd crackly sound on and I suspected at the time it was the NVPROM or the ROM image inside. It's perfect after adding the latest caps =) Well, as perfect as it can be - The NAM-1975 on all the multicarts is missing a music track from the title music I think, at least from what I remember. Pulstar is now awesome, as is Strikers 1945+. It's funny how many things it fixed which I did not expect. One of my 138 in 1's had dodgy sound in Metal Slug 5. It was crackly in at least 2 or 3 samples and always in the same places. Now it is absolutely perfect, as is the one or two Metal Slug games on the 161 in 1 I previously had similar issues with.

 

[mjsaville]

Brilliant mate, about to order 138 in 1 I've been holding off for a bit.

Now I'm considering whether its feasible to mount the dipswitch directly to the case of the 138 rather than at the end of the cable tail.

I've a bit OCD and the cable hanging from the cart doesn't sit well with my head. After watching your video on MVS cartridge cleaning I'm sure you can relate - LOL

Anyway, hats of to you...

 

[GadgetUK]

It's totally possible to mount the DIP switch in the cart somewhere I am sure - although you should check physical space first to be sure where is best to mount it. I've got a 3 digit LCD display and some counters - I want to make a counter circuit, perhaps using PIC or something, whereby you hold down reset to go up through the numbers until you get the game number you need, then release reset and bam - its working on that game.

 

[NeoTurfMasta]

Awesome, thanks for the info on fixing the 138. I also modified my STV Multicart Selector code to work with my 138. I'm waiting for some small 5x5 pcbs that will hold a Arduino nano and the transistors needed for this. I added options for Random Mode and the ability to hide or show the hack games. I'll try to get a video at some point next week.

 

[GadgetUK]

No worries! Would be interesting to see that STV Multicart Selector in action - will check it out =)

These fixes work on the 120 in 1 and 161 in 1 as well. I've just spent a few hours playing various games on my 161 in 1 (and other carts) and everything is perfect and really stable now.

 

[NeoTurfMasta]

The plan is to fit a nano inside the 138 attached to 5x5 pcb, cut a window for the LCD screen and the new pcb will have the select buttons as well.

 

[mjsaville]

It's totally possible to mount the DIP switch in the cart somewhere I am sure - although you should check physical space first to be sure where is best to mount it. I've got a 3 digit LCD display and some counters - I want to make a counter circuit, perhaps using PIC or something, whereby you hold down reset to go up through the numbers until you get the game number you need, then release reset and bam - its working on that game.

That would just take it to the next level, hope you got over the man flu!

 

[fluxcore]

Have yet to confirm yet whether my 120-in-1 has this issue, but will post back if it does (and the results of fix attempt). Mighty glad to hear the 120-in-1 won't require scraping traces though

Thanks for spending so much time fettling this, it's a good bit of detective work!

 

[GadgetUK]

No problem! Try Pulstar, and Strikers 1945+. If you get the sound glitching out as it does on my video then it needs doing. It can be very very random in that sometimes in warm weather I found my cart wouldnt glitch out for hours. I suspect it will need doing in most single slot cases, except for perhaps the newer single slots where maybe theres a newer YM2610, or perhaps it was merged with another IC or something - not sure if they ever did that? Certainly both of my MV-1FZ's have the issue. There's a chance that there could be an 'original batch' of 120 in 1's out there which have the 2 x 47pF bypass caps already on there. None of the 138 in 1's will work 100%, unless maybe they are in a multislot system and perhaps the SDPMPX line is buffered or something. It might not be a noticable problem on multislot systems. If you've got a 161 in 1, please check out Pulstar on that as well.

 

[GadgetUK]

Just a quick update. I've been testing since weekend and this has completely resolved the PCM issues on 161 in 1, 120 in 1 and 138 in 1. So many small glitches on so many games fixed, I am really pleased with these multicarts now. I might order a few more multicarts of different types to see what's going on with those (Maybe 108 in 1, and 150 in 1). I am guessing the 150 in 1 uses the same PCB as the 161 in 1? The interesting thing with the 161 in 1, I can see they used 'wavy tracks' to connect SDRMPX and SDPMPX - whilst this helps, it doesn't solve the problem completely on the 161 in 1 - hence why so many people noticed Pulstar sound on the 161 in 1 being dodgy. I know a couple of people who are waiting for caps to test this on their carts, I will update when I hear back.

https://www.youtube.com/watch?v=jwHHIpLcjdE

138 in 1, and 120 in 1
https://www.dropbox.com/s/nx0fhk0eimacrpi/multicartfix.zip?dl=0

On the 120 in 1, C3 and C4 on the PRG (top) board need the 47pF bypass caps - those fix SDRMPX and SDPMPX. Thought I would mention that as I didn't include reference in the photos I took. Also note you need to add 100nF bypass caps on the under side of all the CPLDs where there are pads.

161 in 1 (150 in 1 also?)
The 161 in 1 just needs 2 caps adding to scratched trace / vias.
https://www.dropbox.com/s/kdf1bd2fqow6xkv/161 in 1.jpg?dl=0

 

[Fygee]

This is awesome! Thanks much! Looking forward to trying it out on my 161 cart.

 

[GadgetUK]

No worries, please post back on how you get on! I am struggling to find anyone that cares about fixing the sound issues - I guess most people just don't care. My problem is I am too much of a perfectionist =/ Does your Pulstar get some break up / volume issues in the music? I used to get the issue sometimes mid level, other times on the end of round music etc.

EDIT: Also, please note what MVS you are using the cart with. The more information we can gather about which systems / carts are affected the better.

 

[mjsaville]

I've also ordered caps to fix the pulstar pcb sound on my 161 in 1, should be here tomorrow. I have a MV-1fz so will post back info on this.

I discovered another issue with my consolized 1fz tonight (it has a voltage display as per your build videos & has the 5v mod).

After it was on for about 50 mins the voltage display started to fluctuate wildly ( normally the display sits at around 4.61v ), then it dipped down to 4.42v and it looked like it reset itself but the screen went blank apart from a gray block on the top left, but the voltage continued to fluctuate and the display showed 4.33v

As soon as I power it of and on again it's fine. I'm thinking it related to me recapping the board which I did about 2 weeks ago, I have also tried a sony nav-u psu like the one you use and I get the same issue only the difference is the voltage on the display starts off higher at 4.73v. Therefor it can't be the Psu, leading me to think it's something up with the 1FZ.

Any idea's Mr Gadget, perhaps I should have started a new thread looking for help.

 

[GadgetUK]

It sounds like that PSU is not providing enough power - It should show 5.00v or there abouts, maybe up to 5.10v is OK, in theory up to 5.25v but I would be wary of going anywhere near 5.25v. The fact its showing 4.73 at the start shows its not up to the job. At around 4.6 / 4.7v with you will get unexpected reboots etc.

EDIT: Just re-read what you put there - Are you sure you are using the same PSU as me? Is it rated 2 amp? You could test with your multimeter to see how much current is being drawn by the MVS, with Multicart it will be around 1.3 amps. To measure that you put meter on amps DC setting, and put one probe to where the 5v connects to the motherboard, and the other probe to the PSU 5v connection. Provided the grounds are connected as normal you should see the current drawn. There's also a chance that the PSU you bought needs recapping. If you've done the stereo mod, and 5v audio, you could remove the Hitachi amplifier for the amplified mono sound. That will improve power a little. I can't think what else would be drawing too much current if its all working OK.

 

[mjsaville]

Superb, will try over the weekend. Much appreciated mate.....

 

[mjsaville]

@GadgetUK - I've had a busy weekend with the mv-1fz.

1. Removed the hitachi amplier - you are right it has given me a bit more power and the unit is no longer having power dips and rebooting - power fluctuates a little but only within 0.03 of the voltage.

I've come to the conclusion I have 1 strange board, after measuring the ampage drawn ( thanks for this by the way ) it draws 1.25 amps with the 161 in and running. I have tried the 2 same PSU's with the amp removed and here are the power readings:

Psu1 4.83v cartridge slot empty, 4.63v playing Plustar; PSU2 Sony nav-u unit 5.01v slot empty, 4.78v playing Pulstar. If I measured both the PSU's with without load and they are around 5.20v. So I don't think it's the PSU's more like the board is making the voltage dip.

Anyway, point 2.

Just fitted the 2 x 47pf caps to the top board on my 161 in 1, but I don't think it's fixed my issue with the music increasing in Plustar though. If you want ? - I can put up a link to the inside of my 161 in 1 ( it's about 2 years old) for reference and I can do a quick vid of the sound on pulstar for you to judge if you like too - happy to help the Neo Geo community!

I'm off to double check your YouTube video, to reference the other sound glitch issues you pointed out and I'll post back (probably) tomorrow night.

 

[GadgetUK]

Your PSUs are the problem with the voltage dropping! The current drawn proves that - at 1.25amps you should have around 5.00 volts, not 4.78 etc. That's not the MVS! Maybe you've got some resistance on the power connector or something - you could try cleaning the socket with contact cleaner or something to see if that helps, but I doubt it will give you a .25v increase. The voltage will drop when the PSU cannot deliver enough current - what you are seeing there is typical with maybe a 1 / 1.5 amp PSU, or a failing 2 amp PSU.

It would be useful to see some pics of your 161 in 1 - where you mounted the caps etc. I've had feedback today from 2 of my friends to say the caps fixed their Pulstar on the 161, and one of them applied the caps to his 120 in 1 and it fixed a lot on there. It might be that part of your problem is the low voltage level, or maybe your 161 in 1 is missing some bypass caps. I think its unlikely the 161 is missing other caps as they seem to be manufactured slightly better than the other carts and seemingly have most of the required caps, except for the 2 x 47pF caps. It would also be useful to see a vid or something so I can hear what sound issues you get with your system!

EDIT: BTW - for the 161 in 1, check out the image I linked at the top of this thread! That's where the 2 x 47pF caps go on the 161 in 1. I don't think I covered it in my video. I fixed the 161 in 1 afterwards.

 

[mjsaville]

@GadgetUK - Quick update on things and I've come to the conclusion I may be mistaken and the 47pf caps probably HAVE fixed my 161 in 1 although the sound on strikers 1945+ seems to fluctuate.

Here are some pics of the inside of my 161 in 1, looks pretty clean and I've not touched it other than add the caps.

http://i87.photobucket.com/albums/k123/mjsaville/IMG_0287_zpsc095d575.jpg

http://i87.photobucket.com/albums/k123/mjsaville/IMG_0288_zps5e10733d.jpg

http://i87.photobucket.com/albums/k123/mjsaville/IMG_0289_zps1acb2a34.jpg

http://i87.photobucket.com/albums/k123/mjsaville/IMG_0290_zps077a8da8.jpg


Apologies for the poor quality of the images, pictures taken with a poor light source and not great, the first one was done on the bench before heading for the carpet for the others.

He's a short vid of strikers 1945+ music playing via the uni-bios jukebox, the sound doesn't just suddenly increase like you, so I think the 2 x 47pf caps have done the trick but the sound seems to pitchy and fluctuates a bit.

Try not to take the piss out of either my Scottish accent LOL and me holding the iPad with my left hand: http://vid87.photobucket.com/albums/k123/mjsaville/161-Strikers%201945_zpsxsrvlofx.mp4

What do you think mate?

MJ

 

[GadgetUK]

With regards to the pics - looks OK but I cannot really tell if you've got the correct points soldered there, although it looks right from the photo, and since Strikers sounds OK there I am guessing its fine now.

With regards to the vid, that sounds totally perfect to me! I cannot hear any issues which I would say were a fault - that sounds fine! If you compared to an actual copy of Strikers on that system I bet you wouldn't be able to tell the difference. How is your audio routed to the TV, did you do the stereo amp board or not? Hopefully someone else will view that and post their opinion but I think that's OK - if anything its going to be the audio output circuit (amp), how its wired etc, and ultimately the TV amplification as well. It could even be clipping somehow, but if there are fluxuations there its very hard to tell from listening to that video!

BTW: Would never take the piss out of someone for their accent! My wife is Scottish =)

EDIT: Great job on the soldering btw there - looks nice and tidy!

EDIT2: If you've not got a stable 5v all the time that will also affect the audio op amp, especially if its as low as 4.7v - maybe that's what you are hearing there?

 

[mjsaville]

Thanks man - I appreciate the feedback.

I'm probably paranoid with the sound due to the power issues and I think you are right about the audio op amp needing the extra voltage.

On another thread you recommended an AES PSU from http://www.robwebb1.plus.com/neogeo/ng.htm

There is a 5v 3amp - "Official SNK Neo Geo AES Mains adaptor/power supply unit (UK/Europe) @ £19.90, this I'm thinking should do the trick.

thanks again mate.

MJ

 

[GadgetUK]

Yes, the official one will work a treat! I never thought of that - I might get one myself at some point =) Just check polarity before you plug it in!

 

[GadgetUK]

This PCM fix also relates to the 150 in 1. Possibly the 111 in 1, 108 in 1, 100 in 1 and the earlier models as well. The 150 in 1 is confirmed.

 

[mjsaville]

Yes, the official one will work a treat! I never thought of that - I might get one myself at some point =) Just check polarity before you plug it in!

@GadgetUK

Ordered a 5V 3amp AES PSU from http://www.robwebb1.plus.com/neogeo/ng.htm on Wednesday via PayPal, it arrived the following day - Brand New and still in plastic - Superb service from Robert. I would highly recommend him to other members.

Before fitting it I changed out the metal DC Socket for a plastic one, I thought it might have less resistance - bought from eBay:
http://www.ebay.co.uk/itm/2-1mm-x-5-5mm-Male-Plug-Female-Socket-Panel-Mount-Jack-DC-Connector-/251315941805?pt=LH_DefaultDomain_3&hash=item3a8398f1ad Only used the socket!

Now I'm getting a solid 5v on the display and the plastic socket seems to be a bit more stable than the original metal one I was using.

You should consider swapping out yours, the PSU is well chunky by the way and totally worth it.

thanks again mate.

Now to mod my 138 in 1 when it comes, still stuck in China due to their new-year. I'm itching to get my hands on it.