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viletim · Joined: 24 Sep 2006 Posts: 104

My FM boards don't sound right - listen to the attached mp3 samples if you don't know what I'm talking about.

All boards I've sold to date have a defective YM2413 sound chip. Admittedly, I've known that there was a problem for a while now but couldn't confirm that it was the YM2413 at fault. It was only when I bought another batch of chips (from a different supplier!) that I could isolate the cause.

I've bought some more, enough to replace all the crap chips. I can now supply a tested functional YM2413 for AU$10 worldwide postage included. If you want one please get in touch.

eviltim ( at ) optusnet.com.au

Replacing the chip is quick and requires nothing more than a butteknife or small screwdriver.

omp · Joined: 13 Nov 2007 Posts: 102

Thanks Tim, is this something where the chip WILL become faulty? Mine sounds fine as it is now (my console plays the sound matching your good recordings).

viletim · Joined: 24 Sep 2006 Posts: 104

No, I don't think so. Maybe only some chips are affected.... I'll crack open another tube of ICs and test a few more from the old stock.

viletim · Joined: 24 Sep 2006 Posts: 104

Perhaps you were just lucky. I just tested seven more chips and they all sound like the bad recording (using Scramble Spirits).

djbass · Posted: Sat Aug 29, 2009 9:48 am

I've always thought mine sounded fine (examples are available with some aztec adventure recordings in the other thread).

However I dug up a copy of Scramble Spirits and tested and it sounds like the 'bad recording'.

I also have another two boards that haven't been used yet, if I get the time I may pop the IC out of them and try in my modded SMS.

rbudrick · Joined: 21 Jan 2005 Posts: 76

Tim, I was wondering if you could maybe post more examples of the sound differences. It seems R-Type and Scramble Spirits are two carts I don't own. Hmm, where;d that list of US games with FM sound go? I could say which ones I have. I have about 63 or so of the US releases, so I know I have some with FM sound.

-Rob

Christuserloeser · Joined: 26 Dec 2004 Posts: 246 Location: Pangea

http://www.smspower.org/forums/viewtopic.php?t=8714

dhau · Joined: 03 Jul 2005 Posts: 36 Location: Toronto, Canada

Er, this is kinda bad and good news I guess. I bough one of the first batch boards, so I need to apply the other fix as well. How much would two good chips shipped to Canada would cost? Also, what can I do with defective chip other then eBay it to some unsuspecting victim? :)

rbudrick · Joined: 21 Jan 2005 Posts: 76

Thanks, Christuserloeser.

Ok, looks like I have:

Cloud Master
Rampage
Rastan
Shanghai
Rescue Mission
Time Soldiers
Wonder Boy III

Thanks if you can supply any examples for these, Tim!

-Rob

viletim · Joined: 24 Sep 2006 Posts: 104

djbass · Posted: Sun Aug 30, 2009 6:29 am

I just tried the other two chips and they all sound the same. I'm not that fussed about it for the time being as I currently have the guts of my system sprawled all over the place while i'm experimenting on it.

viletim · Joined: 24 Sep 2006 Posts: 104

A few people asked me about instructions for replacing the Ym2413. It's pretty straight forward, all you need to do is remove the original from the socket and instert the new chip. Make sure it's inserted the right way around -- the notch on the chip faces towards the centre of the board. I've attached a couple of pictures.

Also attached is a recording from Rampage.

djbass · Posted: Mon Aug 31, 2009 3:13 pm

..or you can use an IC extractor like I did :P

rbudrick · Joined: 21 Jan 2005 Posts: 76

Hey Tim,

I just played Rampage, and mine sounds like the good chip version. I don't hear the distortion in the bad version. However, your music is a bit slower than mine. PAL/NTSC differences? Not sure. I'm in USA, so I'm stumped on that one.

-Rob

ptepid · Guest

I didn't realise you could get FM working in WB3 with the hold-left work around (I have one of the first shipments), so I've only just tried that now. Music sounds fine until the desert level, and then it's basically all noise channel (similar to the distortion in Scramble Spirits). Can't discern the melody at all.

To me it sounds like the rhythmic bass notes are coming out as noise (drum synth). This is especially noticeable in Rampage.

Might do some before/after recordings on WB3 once I have the new IC if someone doesn't beat me to it. ;)

Cheers for your continued work on this Tim.

viletim · Joined: 24 Sep 2006 Posts: 104

rbudrick · Joined: 21 Jan 2005 Posts: 76

Jacko · Posted: Tue Sep 01, 2009 11:12 pm

Tim,

I sent an email off mate :)

The newer chips certainly sound a lot better!

ptepid · Posted: Thu Sep 03, 2009 6:51 am

Just received the new chip today, cheers again Tim!

I've done some before and after recordings for the FM games I have, will try and upload them all. For now I've just uploaded the Wonder Boy 3 Desert level recordings for comparison. It was the most problematic and hence most improved.

ptepid · Posted: Thu Sep 03, 2009 7:44 am

Here's another that made a vast improvement: Time Soldiers. I used to detest the "Primitive Age" theme... it sounded so droning and monotonous. But just listen to proper FM version! It's the drums that were missing, and that makes a world of difference to this tune.

Edit: Bugger, looks like I recorded the PSG version the first time, must have messed up the hold-left trick. Doubt I'll bother putting the old IC back to do another take, but I'll leave the new FM version for anyone wanting to compare to their own.

Uploaded:
- Added Afterburner.
- Added Double Dragon, Fantasy Zone 2, Kenseiden, Great Golf

Didn't upload:
- Rescue Mission: any differences are so minute they aren't audible. Waveforms look basically identical also.
- Golvelius: it's almost identical. Sole difference is the new FM chip uses Brass instruments for the melody in the first dungeon. The old chip didn't switch properly, the melody used the same instruments as the "Store" music that plays beforehand.