SNES S/PDIF vs Built in audio.

[Triaxis]

Digital vs analog snes audio. I just made this video let me know what you think.

http://youtu.be/HlYeA_aqYAA

Thanks for watching.

[shmuppyLove]

Great, now I want to play Crono Trigger again.

As if I don't have enough games on my backlog already that I haven't even started ...

More on-topic though, it's a pretty minor improvement in my opinion. I had to listen very carefully with my SRH440 headphones to really notice a difference. On my speakers at typical volume I couldn't notice it.

Definitely seems like there is a wider response range with the digital, as well as less noise.

I think the main advantage though is that it makes it easier to integrate the SNES into a modern setup, isn't it?

[ZellSF]

Doesn't SNES SPDIF have various compatibility issues because of the weird sample rate? I imagine it would be harder to fit a SPDIF SNES in a modern setup than an analog SNES because of that.

I didn't hear a difference on cheap headphones (shocker) except one track, but that sounded like a volume difference. How did you make sure volume was perfectly matched?

[BazookaBen]

I may have noticed a little noise on analog, though that could be from the recording hardware. Either way I don't think youtube is the best format to test stuff like this.

I'm using analog out on my SNES through some large hifi speakers and it sounds great, so I see no need to do the digital mod.

I think the main advantage though is that it makes it easier to integrate the SNES into a modern setup, isn't it?

Not really. Red and white RCA inputs are plentiful on any modern receiver.

[Triaxis]

YouTube is not the best format for this demonstration indeed. Much like photographing a CRT, the photos never do justice to how it looks in person. I will now start on a downloadable uncompressed WAV file. When i listed back on YouTube the analog and digital sounded closer to the same than they do in person. YouTube degrades audio with compression. In person, there is a lot more harmonic richness, low end clarity, and better defined stereo imaging.

More to come...

PS: I used final cut pro to "normalize" the audio last time. This time a will be using a s/pdif capable sound card to import digitally at 32kHz 16 bit. What you will hear is 1 for 1 what the cs8405 is outputing.

[Triaxis]

Here is the link to the uncompressed audio file. The break out cable to my sound card that can record s/pdif is missing so here is how i recorded this.

1. Analog snes multi out stereo/apogee duet stereo in/Apple Garageband. Record and export at 24 bit.
2 Digital spdif rca out from snes/ViewHD spdif to analog converter/apogee duet stereo in/Apple Garageband. Record and export at 24 bit.

https://drive.google.com/file/d/0BwESjQ ... sp=sharing

[cyborc]

Doesn't SNES SPDIF have various compatibility issues because of the weird sample rate? I imagine it would be harder to fit a SPDIF SNES in a modern setup than an analog SNES because of that.

I didn't hear a difference on cheap headphones (shocker) except one track, but that sounded like a volume difference. How did you make sure volume was perfectly matched?

The main reason I did the mod was because I use headphones a lot and my snes outputs an annoying buzzing sound when using RGB SCART. Thanks to the mod I can get crystal clear audio with no buzz or hum. As far as equipment incompatibilities go, I've tested it on a few receivers (yamaha, sony) and it works without any issues.

I also did the s/pdif mod on the Saturn. It made a noticeable difference in audio quality.

If you're using speakers I don't really see the need to do this mod, because it's a pain in the ass to do (at least for someone of my limited skills!) but for my needs, it was definitely worth the trouble.

[Ed Oscuro]

I did hear the buzz at the beginning of the first sample, but I'm not going to say anything else because I'm not really set up to do an A/B test here...

The previous time I tried listening to the samples, I had a furnace going so eh yeah

[Triaxis]

I finally found the s/pdif adapter to my sound card. Much to my disappointment the RCA jack had broken off. So after some quick soldering it is repaired.


Here is a what the S/PDIF mod truly sounds like recorded at the Super Nintendo's native 32khz 16 bit. This time its only 7MB and in wav format

Behold!

https://drive.google.com/file/d/0BwESjQ ... sp=sharing

[Ed Oscuro]

Finally got a chance to check it out quietly. This is good stuff if you're interested in ripping soundtracks from original hardware, since it eliminates that noise floor. In quiet moments, the noise floor is definitely notable, although the rather jittery SNES sound makes it hard to notice any different when notes are being played. I wonder what replacing a couple secondary components might do for the analog, though.

[naiaru]

How did you do the S/PDIF mod to the Saturn? I know about the gamesx.com link people refer to a lot, but I get lost when they start talking about inverting the de-emphasis high flux capacitor or whatever. I've added seperate analog stereo outs to all my consoles that use SCART to help with that buzzing you're talking about, but it doesn't get rid of it completely. You wouldn't happen to have a simple explanation for what you did, would you? (at the level of something like "solder this to that, then to this, then to this other thing, and finally this, and then you're done")

[BazookaBen]

Here is the link to the uncompressed audio file. The break out cable to my sound card that can record s/pdif is missing so here is how i recorded this.

1. Analog snes multi out stereo/apogee duet stereo in/Apple Garageband. Record and export at 24 bit.
2 Digital spdif rca out from snes/ViewHD spdif to analog converter/apogee duet stereo in/Apple Garageband. Record and export at 24 bit.

https://drive.google.com/file/d/0BwESjQ ... sp=sharing

Thanks for doing this. This is the kind of documentation we need for this hobby, to really know what the hardware is capable of. I actually think the way you have everything hooked up in this post (both recorded to analog input on the apogee) is best, because you're comparing a HiFi DAC's results with the results from the SNES DAC.

That said, it is also a testament to the DAC on the SNES, because I could not tell a difference. I was listening on Grado SR-80's with the volume cranked. Nintendo wasn't messin' with the "Play it Loud" campaign.

One thing of note, though, with your direct SPDIF recording, is that the stereo is reversed. Or it's reversed on your apogee. Probably plugged in backwards somewhere, and not an issue with SPDIF from SNES.

[Ed Oscuro]

comparing a HiFi DAC's results

Actually, which one? There are apparently a number of Cirrus Logic chips that get used for the SPDIF mod, from the cs8405 and cs8506 mentioned on the GameSX wiki, to various newer parts mentioned here. To be sure, the SPDIF output sounds (at least to me) very good already, using even the cs8405.

[Triaxis]

The stereo is probably reversed on the analog recording and should be correct on the digital. For the direct recording i used my delta audiophile 2496 with the rca output I installed on the SNES running to the S/PDIF break out cable from the Delta sound card. The sound card locks sync from the CS8405. I recorded the WAV file at 32k 16 bit. With this method the audio remains digital until you push play on your end

[BazookaBen]

comparing a HiFi DAC's results

Actually, which one? There are apparently a number of Cirrus Logic chips that get used for the SPDIF mod, from the cs8405 and cs8506 mentioned on the GameSX wiki, to various newer parts mentioned here. To be sure, the SPDIF output sounds (at least to me) very good already, using even the cs8405.

I was talking about the ViewHD DAC he used when recording the .AIF file. I don't think the logic chips you're talking about make a difference. The thing with digital/spdif is that the 1's and 0's either get there or they don't, there is no in-between where the quality goes down. It's the same reason HDMI cables can be really cheap and do the job just as well as the most expensive cables.

[RGB32E]

I was talking about the ViewHD DAC he used when recording the .AIF file. I don't think the logic chips you're talking about make a difference. The thing with digital/spdif is that the 1's and 0's either get there or they don't, there is no in-between where the quality goes down. It's the same reason HDMI cables can be really cheap and do the job just as well as the most expensive cables.

Ha! This is where the fun begins!

http://www.hdmi.org/devcon/presentation ... nglish.pdf

http://www.wireworldcable.com/are_all_h ... _same.html

Spoiler

3) The Digital Myths and Misconceptions

‘Contrary to popular belief, transmission of Digital Audio and Video is by no means perfect. The very fact that extensive use of error correction is employed; is a testimony in its self'.

During transmission, digital signal suffers from data corruption/loss due to a variety of reasons, these include bandwidth limitations, jitter, signal attenuation, crosstalk, external EMI (Electro Magnetic Interference) etc. To counteract these problems digital processing systems employ error correction and/or error reduction techniques.

Given the right audio equipment chain, SPDIF output can provide much better audio than stock. About the levels difference, consider the fact that SNES cart audio is mixed with SNES audio after the integrated DAC stage. Also, the amount of jitter in the SPDIF mod can reduce the dynamic range. YMMV. On my setup the levels are about the same from stock audio and my DAC. However, I think my DAC outputs a stronger signal, so that compensates for any potential discrepancy.

Digital vs analog snes audio. I just made this video let me know what you think.

http://youtu.be/HlYeA_aqYAA

Thanks for watching.

If you know what to listen for it's easy to tell the difference even in youtube. Thanks for sharing!

[Ed Oscuro]

I was talking about the ViewHD DAC he used when recording the .AIF file. I don't think the logic chips you're talking about make a difference.

I thought this might be the case, but what confuses me is that I didn't see where that DAC was mentioned. I still think "Digital spdif rca out from snes/ViewHD spdif to analog converter/apogee duet stereo in/Apple Garageband." is a bit ambiguous, since it suggested that the ViewHD was outputting SPDIF via RCA, and ViewHD makes more than one product. More explicit details here would be nice. Of course, I am sure that pretty much any DAC for SPDIF is going to work much better than the old analog output, but still I think there's some details to be filled in here.

The thing with digital/spdif is that the 1's and 0's either get there or they don't, there is no in-between where the quality goes down.

I didn't mention it at the time, but at the least the chip being used for the SPDIF encoding has to support asynchronous output due to the nonstandard rate of the SNES audio. But if all the chips mentioned support this, it's no big difference. It is important not to change this to a "standard" rate though.

So oops, I didn't really write down the things that I wanted more detail on, so maybe now I could get that.

[RGB32E]

I didn't mention it at the time, but at the least the chip being used for the SPDIF encoding has to support asynchronous output due to the nonstandard rate of the SNES audio. But if all the chips mentioned support this, it's no big difference. It is important not to change this to a "standard" rate though.

Asynchronous mode for the SNES is irrelevant (external master clock signal), as the master clock signal should be used for synchronous operation. If your receiver, DAC or processor won't lock onto the 32,040Hz signal from the SNES, perhaps you should consider replacing your receiver, DAC or processor.

http://www.alpha-ii.com/Info/snes-spdif.html

The CS8405A allows for asynchronous operation. So, if necessary, you can supply your own master clock (OMCK) by using a more accurate crystal to ensure 32kHz output. However, doing so will result in samples being dropped or repeated.

Only systems like the game cube require asynchronous mode as a master clock signal isn't available or been discovered on the system PCB.

[Ed Oscuro]

Asynchronous mode for the SNES is irrelevant (external master clock signal), as the master clock signal should be used for synchronous operation. If your receiver, DAC or processor won't lock onto the 32,040Hz signal from the SNES, perhaps you should consider replacing your receiver, DAC or processor.

Whoops, I misread my own source there. Thanks.

Only systems like the game cube require asynchronous mode as a master clock signal isn't available or been discovered on the system PCB.

And interesting continuation of that information here, thanks.

[CkRtech]

<bump>

Getting ready to do this mod myself. Got the CL chip mounted to a board, put headers in the board and into a small project board. Next will be bridging the legs and finally wiring to the chip and output. Hope it is worth it....

[cyborc]

<bump>

Getting ready to do this mod myself. Got the CL chip mounted to a board, put headers in the board and into a small project board. Next will be bridging the legs and finally wiring to the chip and output. Hope it is worth it....

Good luck! it's definitely worth it.


Helder from Assemblergames designed PCBs for use with SNES and Saturn S/PDIF mods. I've used them and they work great. you can order them here

https://oshpark.com/shared_projects/4Il0ShMQ

https://oshpark.com/shared_projects/Tbnwy2yK

[CkRtech]

Ooooooh. Nice.

Dang. Well, next time...the difficult soldering is behind me already.

That is definitely a great resource. Thanks for sharing, cyborc!

[cyborc]

you bet. The first SNES I modded, I went with the method you're using. Those oshpark boards save so much time!

[RGB32E]

User "L-Train" released his up-sampling SNES SPDIF circuit on OSH Park a couple of weeks ago.

https://oshpark.com/shared_projects/Qdy2pZzr
http://www.head-fi.org/t/740288/super-n ... t_11227890

Looks slick. I'll share my results when I get this assembled and installed! I wonder if this circuit can be tailored for the N64 since this circuit contains a sample rate convertor for up-sampling.

[CkRtech]

http://www.head-fi.org/t/740288/super-n ... t_11227890

The OP of that thread seems familiar somehow....

[L-Train]

User "L-Train" released his up-sampling SNES SPDIF circuit on OSH Park a couple of weeks ago.

https://oshpark.com/shared_projects/Qdy2pZzr
http://www.head-fi.org/t/740288/super-n ... t_11227890

Looks slick. I'll share my results when I get this assembled and installed! I wonder if this circuit can be tailored for the N64 since this circuit contains a sample rate convertor for up-sampling.

The N64 is something I had in the back of my mind when I was designing the circuit, but since I don't have an N64 I couldn't test it out. The SNES S/PDIF board is configured to only accept 16-bit right-justified audio, and thankfully the N64 RCP outputs that same format (according to the datasheet of the N64's audio DAC, the BU9480F) so it might actually work! The only thing I'm unsure of is where to connect the /RST line as I haven't found a pin diagram for the RCP. Perhaps just tying /RST to 5V would suffice, though.

[RGB32E]

Oh! I didn't realize you were already a member of this forum! Very excited to try your circuit! I take it that D+ is connected to center pin, and D- is to be connected to the RCA "ground"?

[L-Train]

Oh! I didn't realize you were already a member of this forum! Very excited to try your circuit! I take it that D+ is connected to center pin, and D- is to be connected to the RCA "ground"?

Yup, that's correct.

[RGB32E]

Have you considered adding a SRC bypass option?

[CkRtech]

<Gets information from L-Train and orders parts>

Thanks, L-Train!

<Receives parts in the mail and starts getting ready to solder>

Why u hate me, L-Train?