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

nikoskon

Bashful Neophyte
Joined
Jan 12, 2021
Posts
13
I just purchased one too, and it is a rev.4 as well. I suppose it will be a good idea at some stage to replace the FMZ caps with a better brand, but that can be done late i suppose.

Is it also better to remove C3 completely, or not necessary?

Also, i had read somewhere that the 161 is not really compatible with the MV1. I have just used it on my MV1-1 and it works fine so far. Haven't tried all games of course, but so far so good.
 

gtsamour

Twinkle Star Sprite
Joined
Oct 28, 2007
Posts
33
Hi, I am going to order one of these carts from Aliexpress soon.
What is the best option to buy at this time? Sound quality and problems free wise.

I saw a cart 161 in 1 that it was supposed to have the games in alhabetical order which is nice but I can't find it now.

Any help is appreciated guys, even links.
 

dragonpt

Over Top Auto Mechanic
10 Year Member
Joined
Oct 19, 2008
Posts
862
I have the mvs 161-1 rev 2 ( comes stock with both pins bridged)
Already did the pcm sound fix ( both 47pf caps)
I see some people removed c3 due to "tinny sound" ?
Could you elaborate a bit more,what you mean?

Any noticeable difference with it removed?

Thx
 

maki

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Jan 1, 2022
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171
Hi all, got an MVS 161 in 1 cart here that will not improve its sound at all, added the 47pF caps bypass, added missing bypass caps on the board, no avail, no improvement at all

Just noticed it is missing its crystal (top right), haven't seen pics on the web yet where it's missing, does anyone know what frequency its swinging at?
I can only read 11ish Mhz, maybe someone knows the precise value and has other tips on what I could try.
 

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maki

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Jan 1, 2022
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Thank you @ack :)

I shouldn't be surprised at all that you'd have a scan of a 161-in-1 PCB lol

turns out I'm an idiot, they've soldered the crystal to the other side, swapped it for another one (these crystals are quite common btw.), no change, PCM sound is still useless, mostly noise

(can't upload MP4s here so I'm linking it)

I'll try to probe it with my analoge scope
 

maki

NEST Puppet
Joined
Jan 1, 2022
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171
okay, after adding plenty of more bypass caps and polymer electrolytic caps, still no improvement

PXL_20220604_120202373.jpg

I got desperate, so even though I could not see a single cold solder joint on these weird flash IC with their even weirder flex PCB, I've decided to reflow them, on the IC side but also on the PCB side, had to cut the rubber that was used to glue the flash ICs to the PCB

PXL_20220604_120004979.jpg

PCM sound works now :)

nevermind the mess, just testing/experimenting, "make it work, then make it clean"
 
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