No-cut SNES digital audio mod:

[FBX]

Borti in regards to your designs: That's actually the idea I had for the deluxe board, using metal standoffs from the screw hole terminals where the RF box used to be. I've even already got the standoffs I planned to use, which came from my pinball machine parts box (pinball restoration was my first love before console modding). So we are on the same page there. This board was supposed to be a cheap 'regular' board with dual output so people could choose their own hookup method: Coaxial for no-cut modding or Optical for mounting directly into the squared off port hole. As such, I couldn't plan on using the standoffs in order to appease both options in a single board. You designs are ideal for two boards, but I wanted to avoid having to make two different boards. It's only a small price to pay by mounting the combo board without a standoff, at least I thought so anyway.

The reason is simple: I also replaced the CS8406 with a DIT4096 from TI, which has a TSOP package instead of a SOIC.

So does the CS8406. I'm looking at one right now and it's easily only (well okay maybe half the size) of the SOIC package.

Here's a pic I took of the -CZZ beside the -CSZ:



I'll write some more comments, but I gotta head to the store right at the moment.

[nmalinoski]

This is probably a ludicrous suggestion, because most home audio equipment can't use it, but would balanced analog audio-out also achieve noise reduction? If you tap the analog output, after the DAC, you could catch both internal and cart audio.

Then again, just imagine an SNES with two XLR ports on the back.

It's sort of on track with my eventual deluxe board idea. I've already spaghettied together the parts to test the idea and it works, but here's the train of thought: If you can intercept the audio directly from the two caps on the board just after the final output from the 'S-Mix' chip, and immediately digitize that signal, you'd get a pure and clean capture of the entire mixed stereo audio. I tested the theory out and sure enough, the 48Khz digital output of that mixed signal sounded clean with no audible distortion. So I got to thinking the ultimate digital audio board would have a single output and a small toggle switch (that fits through the channel selector for no-cut modding). You then have 48Khz clean ADC of the mixed stereo lines that include cart and ext audio, and with the flick of the toggle switch, you'd get the original digital-to-digital feed of the SNES music and sound. It's the best of both worlds in one mod board, and the toggle switch would make it easy for users to switch to their preference on demand.

Does the stereo signal stay clean between the caps and the multi-out? If so, you could make a Plug-n-Play breakout that fits between the regular AV cable and the multi-out, provides TOSLINK and/or coax, and could be powered by the 5V pin.

[FBX]

Does the stereo signal stay clean between the caps and the multi-out? If so, you could make a Plug-n-Play breakout that fits between the regular AV cable and the multi-out, provides TOSLINK and/or coax, and could be powered by the 5V pin.

It probably stays pretty clean, but I worry about the proximity to video lines in the multi AV port itself. It may be just paranoia on my part, but I like tapping the lines before it even gets to the multi AV.

BTW, Borti did make me aware of a minor mistake in the rating for R1 on my board: Cirrus Logic's diagram weirdly doesn't show the actual resistor value that should be used for R1. Instead they expect you to subtract the pin's resistance from 374 Ohms, meaning you would need 347.5 Ohms for R1. Completely bizarre logic (I guess Cirrus means bizarre LOL), but it didn't seem to harm the output when I tested it with 374 Ohms. I'll be bumping down to 348 Ohms resistor for R1 as that should be within tolerance range.

[darcagn]

Not true- I've always thought it's been a great idea to obtain better audio fidelity from old systems (and this isn't the first digital audio output mod for the SNES). If you are bypassing the internal SNES DAC, then you are using an external DAC of some sort. Otherwise, you wouldn't hear sound.

You are making this out to be way more complicated than it needs to be.

Yes, the audio needs to be converted to analog at some point in order for the human ear to receive it.
However, the audio is digital in origin on the SNES mainboard.

So, we already know that we have digital audio that at some point needs to be converted to analog.

The question is when is the best point to convert the digital to analog?

The ONLY time it would make sense to convert to analog first is if the SNES DAC is somehow superior, which is highly unlikely and we have no reason to assume so.

However, there's plenty of reason to convert after transport.
1) Transmission of analog audio is lossy
2a) The SNES's output is an all-in-one connector, with analog video signals, power signals, and audio signals all in one cable, which makes it especially prone to interference
2b) The primary way most people in this community get AV from the SNES is through SCART cables, which are notorious for this issue
3) The DAC used by the SNES is in all likelihood to be inferior to any DAC being used in conjunction with this mod

Four years ago I modded my SNES, PlayStation, Saturn, and Dreamcast with this mod. I have used it on or tested it with four different Pioneer branded receivers in that time span, all with vastly superior results to analog audio on the same receivers.

Why is it so superior? Because I like to play my music LOUD, and the noise floor with this method is vastly lower with the SPDIF mod.

I dream of the same mod being available for NES and Genesis, two consoles with sound I love, but those two consoles have synthesis chips that output in analog and thus there is no way to tap a digital signal. Unfortunately when I play those consoles, I have to turn the audio down, because the silent parts of games are way too noisy.

How many people prefer vinyl to lossless digital downloads

A silly comparison, considering none of the reasons vinyl is preferred applies to the Super Nintendo.

The two primary reasons are:
1) Modern music is often mixed to be as loud as possible, sacrificing dynamic range. Making vinyl records like this is difficult and unreliable, so they often receive a separate mix with less loudness and more range, which is obviously preferred by audiophiles. That superior mix could easily just be released on digital to the same acclaim, but isn't due to record company politics. None of this applies to the Super Nintendo.
2) Purists believe that music from instruments (analog) should be recorded in analog, mixed in analog, and released in an analog format, which is an argument that makes sense. However, none of this applies to the Super Nintendo.

[Lawfer]

The ONLY time it would make sense to convert to analog first is if the SNES DAC is somehow superior, which is highly unlikely and we have no reason to assume so.

As a matter of fact the analog audio quality of the SNES revisions (1CHIP, 1CHIP-Mini) are inferior to that of the launch SNES consoles.

[FBX]

The ONLY time it would make sense to convert to analog first is if the SNES DAC is somehow superior, which is highly unlikely and we have no reason to assume so.

As a matter of fact the analog audio quality of the SNES revisions (1CHIP, 1CHIP-Mini) are inferior to that of the launch SNES consoles.

Doesn't surprise me. The DAC in the SNES consoles I have (APU, 1CHIP, mini) all use a tiny IC the size of a few mm. Probably a cheap knockoff too.

[borti4938]

The reason is simple: I also replaced the CS8406 with a DIT4096 from TI, which has a TSOP package instead of a SOIC.

So does the CS8406. I'm looking at one right now and it's easily only (well okay maybe half the size) of the SOIC package.

Oh, yeah the CS8406 also has a TSOP package. Forgot about that. Your picture shows everything ^^

The other reason I was looking for was a transmitter which does not allow 192kHz. The DIT4096 allows for 96kHz, which is enough here and reduces the costs a bit. This was the other not that obvious reason.

[tjstogy]

You are making this out to be way more complicated than it needs to be.

I wasn't trying to Someone pulled my post apart into a thousand comments and I had to address them (since he didn't want to be rude.)

The question is when is the best point to convert the digital to analog?
However, there's plenty of reason to convert after transport.

Thank you for explaining this... was truly what I was trying to figure out in the first place (which was: show me how this is helpful).

none of the reasons vinyl is preferred applies to the Super Nintendo.

By offering the comparison was more to suggest "what is correct when it comes to audio?" but your concise explanation has made me see the light, and I thank you.

So next question-- is it feasible one could further develop this chip to include a new onboard DAC so that it connects to the existing multiout? Effectively it would be like a DAC upgrade-- for those who have the typical scart switch setup without a receiver.

[borti4938]

possible. But I don't see the need for replacing the DAC inside the SNES. Maybe my ears are not fine enough for that.

For me the digital audio mod is a neat way to connect my SNES directly to my sound boxes. Although most of the time they are switched off and I use the internal TV speaker.

[tjstogy]

So....this could effectively lead to a DAC upgrade chip to replace the apparently shitty one that's inside of the 1Chip SNES

possible. But I don't see the need for replacing the DAC inside the SNES. Maybe my ears are not fine enough for that.

For me the digital audio mod is a neat way to connect my SNES directly to my sound boxes. Although most of the time they are switched off and I use the internal TV speaker.

[bobrocks95]

Why is it so superior? Because I like to play my music LOUD, and the noise floor with this method is vastly lower with the SPDIF mod.

Sorry to add to the noise of silly audio questions, but can you explain why coax is better than SPDIF? Is that always the case, or just between the two mods for retro consoles that are available?

[darcagn]

Why is it so superior? Because I like to play my music LOUD, and the noise floor with this method is vastly lower with the SPDIF mod.

Sorry to add to the noise of silly audio questions, but can you explain why coax is better than SPDIF? Is that always the case, or just between the two mods for retro consoles that are available?

I think you're getting confused.

S/PDIF (Sony/Phillips Digital Interconnect Format) has two types of transmitters: coax and optical. The optical transmitter is often called TOSLINK.

Optical S/PDIF (TOSLINK) and Coax S/PDIF can transmit the same exact digital audio information. So they should sound exactly the same.

Other than that, the only differences are tiny. TOSLINK cables can be snapped when bent. Coax cables, being conductive material, could transfer interference from one device to another (which is really just audiophile bullshit anyway, since the audio signal itself wouldn't be affected).

I use coax in my console mods because it's easier and cheaper to get orange panel-mount RCA connectors than panel-mount TOSLINK connectors. And in the case of the SNES you can reuse the existing stuff. And I have way more spare RCA cables laying around (you can use any old RCA cable) than TOSLINK cables.

[Ikaruga11]

So same sound quality, but coax is cheaper and easier to use? And it can use the RF port of consoles so no cutting is done?

[bobrocks95]

Why is it so superior? Because I like to play my music LOUD, and the noise floor with this method is vastly lower with the SPDIF mod.

Sorry to add to the noise of silly audio questions, but can you explain why coax is better than SPDIF? Is that always the case, or just between the two mods for retro consoles that are available?

I think you're getting confused.

S/PDIF (Sony/Phillips Digital Interconnect Format) has two types of transmitters: coax and optical. The optical transmitter is often called TOSLINK.

Optical S/PDIF (TOSLINK) and Coax S/PDIF can transmit the same exact digital audio information. So they should sound exactly the same.

Other than that, the only differences are tiny. TOSLINK cables can be snapped when bent. Coax cables, being conductive material, could transfer interference from one device to another (which is really just audiophile bullshit anyway, since the audio signal itself wouldn't be affected).

I use coax in my console mods because it's easier and cheaper to get orange panel-mount RCA connectors than panel-mount TOSLINK connectors. And in the case of the SNES you can reuse the existing stuff. And I have way more spare RCA cables laying around (you can use any old RCA cable) than TOSLINK cables.

Ohhh, I see where I was confused. I misread that section of your post as "the noise floor with this method is vastly lower than with the SPDIF mod," making me think there was a distinction between adding a coax port or an optical port. And I'm not sure I fully realized that optical and coax used the same signal format.

Thanks for the clarification.

[nmalinoski]

So same sound quality, but coax is cheaper and easier to use?

Depends on who you're talking to. For me, TOSLINK is easier to work with, because that's what my home theater receiver accepts, it's what's on my pre-ARC LCD TV for audio-out, and it's what's used by all game consoles that will do digital audio outside of HDMI. (So, PS2, Xbox, Xbox 360, PS3, PS4, Xbox One?)

For someone like me to use coaxial S/PDIF, I would need one or more coax->optical converters, which adds complexity and yet another wall wart.

[FBX]

So same sound quality, but coax is cheaper and easier to use? And it can use the RF port of consoles so no cutting is done?

All of the above, and I will point out again that optical is limited in how long it can be. The longer the line is, the more it is prone to jitter. Audiophiles always recommend the shortest possible runs when using optical, whereas a hefty properly shielded coaxial cable can be run far greater distances without issue.

The downside as mentioned is optical is far more 'popular', so coaxial takes a back seat in equipment. My own receiver has 5 optical inputs and only 1 coaxial. But I'm told people often get coaxial-to-optical converters when needed.

[Einzelherz]

The ONLY time it would make sense to convert to analog first is if the SNES DAC is somehow superior, which is highly unlikely and we have no reason to assume so.

As a matter of fact the analog audio quality of the SNES revisions (1CHIP, 1CHIP-Mini) are inferior to that of the launch SNES consoles.

Mind you that this, like many other facts in the AV (and in this case specifically, the retro gaming) community, is significantly subjective. Data and graphs may show that the first board's DAC is (vastly?) superior but if you're a normal human, like myself on most days, you might not notice any difference.

[Lawfer]

The ONLY time it would make sense to convert to analog first is if the SNES DAC is somehow superior, which is highly unlikely and we have no reason to assume so.

As a matter of fact the analog audio quality of the SNES revisions (1CHIP, 1CHIP-Mini) are inferior to that of the launch SNES consoles.

Mind you that this, like many other facts in the AV (and in this case specifically, the retro gaming) community, is significantly subjective. Data and graphs may show that the first board's DAC is (vastly?) superior but if you're a normal human, like myself on most days, you might not notice any difference.

Apparently the difference is quite noticeable, here are comparison videos:

1CHIP/Mini SNES: https://www.youtube.com/watch?v=VWOhN3OdMQ4

Launch SNES: https://www.youtube.com/watch?v=To1B7vXvaNc

inb4 "it's the fucking same!":

https://www.youtube.com/watch?v=wrmfX8QtBfA&t=0m4s

[Einzelherz]

Again, as my point above explained, I've never noticed a difference with my HVC or either of my 1chips. I have a copy of Rockman x2 so I'll go give it a listen, though it's not 100% apples to apples.

edit: if that error is common on Megaman X2, it certainly isn't on the Japanese version. Across my four SNES (HVC, 1c01, 1c03, Mini) I didn't hear anything like the sample linked above.

[Joelepain]

Just to address this little tjstogy different.
Really I apologies if you read my post the inapropriate way, but that really wasn't my goal.

Doesn't exist. It's still in analog.

Of course I know "digital audio doesn't exist" and needs to be converted to analog at one point or another. But you're nippicking here. Just replace "digital audio" by "digital audio transmission" in my post and maybe you'll see I'm not that ignorant...

So my whole point was that of course all the point you raised about digital vs analog make sense, but on an audiophile forum, not this one (or at least not this specific thread)
If someone is interested in an SNES SPDIF mod, than we assume that this person is already aware of the digital vs analog shenanigans(which darcagn take the time to greatly explain). We won't need to repeat it for every single mod of every single console that's coming out.
By doing that we're filling the forum with useless post (which I'm ironicaly doing too by writing this post) and we end up with thread like the xrgb-mini one where every 10 pages people come asking the same questions again because it's a pain to search through it.

One point that I would have prefer to see be raised for example, is the question of resampling. Knowing that not every spdif receiver accepts the 32kHz samplerate of the Snes, does this mod can provide any kind of resampling? And with which quality? (and in this case it make more sense for me that we talk about high quality resampling Vs cheap resampling Vs using the dac of the snes)

[borti4938]

So....this could effectively lead to a DAC upgrade chip to replace the apparently shitty one that's inside of the 1Chip SNES

possible. But I don't see the need for replacing the DAC inside the SNES. Maybe my ears are not fine enough for that.

For me the digital audio mod is a neat way to connect my SNES directly to my sound boxes. Although most of the time they are switched off and I use the internal TV speaker.

I ordered now a suiteable DAC. Unfortunately I haven't found a 1:1 pin compatible replacement. So, if everything goes fine, I will design a small adapter board.

I'll let you know

[tjstogy]

I will design a small adapter board.

Siiiiick!!! This would mean a chip that offers better SNES audio for everyone, not just those who use an external receiver/dac. Borti you're a genius.

BTW: I found the following threads helpful and relevant to this mod, for those interested:

viewtopic.php?f=6&t=49774&start=0

https://www.head-fi.org/threads/super-n ... ou.740288/

[bond.san]

My L-Train mod
This mod requires an audio receiver that accepts 96 KHz

Only tested on a sound bar.
Probably good for surround sound games
https://www.gamnesia.com/articles/throw ... nd-on-snes

also Thank you borti for your previous mods

[darcagn]

I will design a small adapter board.

Siiiiick!!! This would mean a chip that offers better SNES audio for everyone, not just those who use an external receiver/dac. Borti you're a genius.

I mean, sure you could, but 99% of the advantage of this mod in my opinion is getting the digital signal out of the SNES as the interference on even the best SCART cables is still too much compared to lossless, crystal clear digital audio. So I question the how many people would really go for just a DAC upgrade.

[FBX]

I'm still going for the 48Khz resample of the S-Mix output on the next board, using a toggle switch for 32 Khz raw SNES digital audio as needed. Borti brought up the idea of possibly using the SNES clock to control digitization of the cart lines separately and then mixing the two digital feeds into one using a programmable audio processor, but I'm not keen on the idea of crunching 44.1Khz MSU-1 audio down to 32 Khz. Really the toggle switch idea is my best win win scenario: Sticklers for pure original SNES audio can switch to the 32Khz feed, and those that don't care about everything be resampled to 48Khz can leave the switch in that position.

[donluca]

Unfortunately when I play those consoles, I have to turn the audio down, because the silent parts of games are way too noisy.

Not completely true, as there are way you could improve the noise floor of those.

1 - Get a model 1 Mega Drive and use the front output jack. Also, try to swap the lousy 3,5mm connector for a nice sturdy 6,3mm one, it will make a better contact.

2 - Recap the thing, not just the audio part, but the entire regulator part using high-ESR cap with low resistance. Also, try to use polyester (and when space and money allows, polypropylene) caps for small caps, especially in the audio section.

3 - Get a good PSU. Really. It will give you a much cleaner sound with lower noise floor. You can use a 12V PSU, the regulator is able to get up to 13,5V and there's enough dissipation it won't overheat.

4 - Make sure you have everything connected to the same power outlet, trust me, it will save you from several headaches due to unwanted ground loops.

I'm still going for the 48Khz resample of the S-Mix output on the next board, using a toggle switch for 32 Khz raw SNES digital audio as needed.

If the chip you're using allows it, try first to upsample all the way to the chip's limit (96Khz, 24bit is fine) and then downsample down to 48khz 16 bit and make sure to use dithering to move unwanted noise to the inaudible band. Remember that 32khz audio is out of spec for most standard audio equipment who will accept 44.1Khz and 48khz.

[FBX]

I'm still going for the 48Khz resample of the S-Mix output on the next board, using a toggle switch for 32 Khz raw SNES digital audio as needed.

If the chip you're using allows it, try first to upsample all the way to the chip's limit (96Khz, 24bit is fine) and then downsample down to 48khz 16 bit and make sure to use dithering to move unwanted noise to the inaudible band. Remember that 32khz audio is out of spec for most standard audio equipment who will accept 44.1Khz and 48khz.

I'll be digitizing from the S-Mix, which is already analog audio by that point, so it won't be an issue. My own tests with digitizing that feed to 48Khz already sounded great, so I'm now in the phase of mapping out the schematic in Eagle. Speaking of which, the schematic is going to be too large for the free version of Eagle, so I'm going to have to pony up money to pay for the monthly sub ><

[Lawfer]

Speaking of which, the schematic is going to be too large for the free version of Eagle, so I'm going to have to pony up money to pay for the monthly sub ><

Maybe try raising money through Patreon or something? Or maybe even try IndieGogo or Kickstarter and offer Digital Audio upgrade board kits as rewards?

Just an idea, but this kind of retro gaming modding money raising stuff is not unheard of, just recently some guy did the same thing for custom made Dreamcast and Saturn PSUs:

https://www.indiegogo.com/projects/drea ... in-power#/

https://www.indiegogo.com/projects/satu ... wer-supply

[donluca]

I'll be digitizing from the S-Mix, which is already analog audio by that point, so it won't be an issue. My own tests with digitizing that feed to 48Khz already sounded great, so I'm now in the phase of mapping out the schematic in Eagle. Speaking of which, the schematic is going to be too large for the free version of Eagle, so I'm going to have to pony up money to pay for the monthly sub ><

Pardon my ignorance, so you're putting an additional ADC and DAC (external of course) stage?

Tomorrow I'll be doing some research on how SNES audio works so I'll understand better what's going on.

[bobrocks95]

I will design a small adapter board.

Siiiiick!!! This would mean a chip that offers better SNES audio for everyone, not just those who use an external receiver/dac. Borti you're a genius.

If you're at that level of an audiophile that you'd solder in a replacement DAC for your SNES, what kind of audio setup do you have that doesn't include some kind of receiver or preamp? Am I missing something?