Which model has better sound ?

2008-10-10

I recently got a European SNES and a SFC... JP one has a separate SPC module, EU one not. Which has better sound, if there's a difference.
One of the units will become a modding guinea pig and my primary use system...
Reason I'm asking is that I don't have any games yet and I'm too lazy to build a flashcart(adaptor)

SNES doesn't seem to be a very moddable system... MD2 ( http://www.hot.ee/tmeeco/MYSMD2.JPG ) is my fav when it comes to modding...

2008-10-11

The SNES audio is digital and generated by a DSP. I think they all use the same DAC chip, a 6379A, so it will all sound the same.

You could make a high quality DAC and filter circuit for it on a little board.

This guy made a digital audio out http://gamesx.com/wiki/doku.php?id=av:snes_sp_dif which is kind of overkill

For modding go with the one without the APU, it will be easier to access.

I made a new audio mixer circuit for my MD1, and it didn't sound right till I added a capacitor for low-pass filtering. Does yours include one of those? How does it sound?

2008-10-11

I do no filtering whatsoever, having some filtering there makes things sound wrong IMO... high freqs get lost etc. I have quite a few recordings everywhere, I need to find the links...
Some comparsions of different systems...
http://www.spritesmind.net/_GenDev//for ... .php?t=320
Before and after :
http://www.sega-16.com/forum/showpost.p ... stcount=60
Some more comparsions (what I tell there is quite wrong...):
http://www.soundshock.se/phpBB2/viewtopic.php?t=149
Basically my MD2 sounds like Kega Fusion does... undistorted and unfiltered YM2612 output + the PSG.
I have the schematic somewhere too, 6 transistors plus handful of resistors...

As for SNES, The DAC maybe same, but analog part certainly isn't... I think I'll go for the separate SPC model, as its analog part seems simpler, thus modding becomes more easier... and my Euro SNES has the board covered with non transparent paint or something on one side which makes all research quite pain :/
I actually try to get rid of any filtering there might be... I want to hear the high freqs that tickle your ears

2008-10-11

Hmm the 2nd one does sound really good. But I mean playing Sonic2 it sounded off without the cap, like the ring and jump sounds. The new circuit I made did sound way better then the crummy built in one tho.

Now for the SNES, you shouldn't leave the filter out. Its called a reconstruction filter, and is part of the DACs operation.

The most you will get is 16kHz of sound, everything higher will be aliasing noise. So make a nice quality 16kHz 2nd order filter, and you will keep all the good sounds!

2008-10-12

cybertron wrote:

Hmm the 2nd one does sound really good. But I mean playing Sonic2 it sounded off without the cap, like the ring and jump sounds. The new circuit I made did sound way better then the crummy built in one tho.

This sounds like you're overloading (I don't know exactly the cause) YM2612 output which causes such distortion... I had quite a bit of trouble getting rid of it, I spent 1 night doing live tests. My mod only works for MD2... http://www.fileden.com/files/2008/4/21/ ... /CCAM2.jpg
(older version without 32X support... which is just the matter of another pair of 750ohm resistors...)

cybertron wrote:

Now for the SNES, you shouldn't leave the filter out. Its called a reconstruction filter, and is part of the DACs operation.

The most you will get is 16kHz of sound, everything higher will be aliasing noise. So make a nice quality 16kHz 2nd order filter, and you will keep all the good sounds!

I actually prefer aliased noise rather than muffled noise... (though the muffleness is caused by low quality samples in many cases...). I disable all interpolation etc in emulators to get the sound I consider good.

2008-10-12

Actually, without a reconstruction filter you get images at 32kHz, well above audible range (I just tried simulating it in software as well). So it'll sound fine without any post-DAC filtering.

2008-10-12

As I understand it, CD players use a reconstruction filter and "oversampling" (digital upsampling to make the analog stage easier) because some stereo equipment has trouble with frequencies above 24 kHz.

2008-10-12

blargg wrote:

Actually, without a reconstruction filter you get images at 32kHz, well above audible range (I just tried simulating it in software as well). So it'll sound fine without any post-DAC filtering.

A DAC running at 32kHz will produce not only the desired image from 0-16kHz, and the undesired image from 32-48kHz, but also a reversed undesired image from 32-16kHz.

There is evidence that we can sense frequencies above ~15-20kHz, although we can't directly perceive them. Leaving the filter out will make percussion (primarily, other high sounds too) sound crisper, possibly too crisp. It may also make high pitched instruments with strong harmonics sound out of tune.

Most (inexpensive) PC soundcards have a first-order lowpass at 10kHz.

2008-10-13

That extra crispness is what I'm wanting. I hope the high-freq instruments getting out of tune won't happen (often).