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Discussion Starter · #1 ·
Hello all. I am razor close to purchasing a new receiver but one aspect that most intrigues me is if new receivers will accept weird digital formats. For example: I modify alot of old video game consoles to have modern capabilities, one of those consoles, the Super Nintendo Entertainment System, is capable of outputting digital audio with a little bid of soldering, but the format it sends the signal is at 16-bit 32,000 kHz, which is different than the standard 16-bit 44,100 kHz. Most new receivers I see out there claim to be 20 Hz-20 kHz, but that doesn't necessarily mean that it will accept a weird non-standard rate...can you all help me to know which specs to look for to know for sure that the receiver is capable of decoding strange signals?
 

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Quote:
Originally Posted by zedrein /forum/post/19520862


...the Super Nintendo Entertainment System, is capable of outputting digital audio with a little bid of soldering, but the format it sends the signal is at 16-bit 32,000 kHz, which is different than the standard 16-bit 44,100 kHz. Most new receivers I see out there claim to be 20 Hz-20 kHz, but that doesn't necessarily mean that it will accept a weird non-standard rate...can you all help me to know which specs to look for to know for sure that the receiver is capable of decoding strange signals?

For the info that you are seeking, the measured audio passband (20 Hz to 20 kHz) is irrelevant. Standard digital sampling frequencies include 32 kHz, 44.1 kHz, and 48 kHz. Nearly all DACs will be able to lock onto and convert these three sampling rates, though 32 kHz is rarely used any longer.


AJ
 

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Discussion Starter · #4 ·
Thanks, guys. I suppose that it should also be noted that the SNES actually outputs it's audio at 32,040 kHz, it's not even technically 32,000 kHz. So in the case of a receiver, like the Pioneer 9140, that says it can take 32 kHz-192 kHz that means that anything in between those sample rates can be decoded? So it can be really awkward like 56,000 kHz and still be decoded and amplified because it falls in between 32 & 192? Thanks again for your help, gentleman!
 

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Quote:
Originally Posted by zedrein /forum/post/19521058


Thanks, guys. I suppose that it should also be noted that the SNES actually outputs it's audio at 32,040 kHz, it's not even technically 32,000 kHz. So in the case of a receiver, like the Pioneer 9140, that says it can take 32 kHz-192 kHz that means that anything in between those sample rates can be decoded? So it can be really awkward like 56,000 kHz and still be decoded and amplified because it falls in between 32 & 192? Thanks again for your help, gentleman!

No this is wrong assumption. Normal range is 44, 48, 88, 96, 176, 192. 32kHz may or may nor work, but do not count on it too much.
 

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Quote:
Originally Posted by zedrein /forum/post/19521058


Thanks, guys. I suppose that it should also be noted that the SNES actually outputs it's audio at 32,040 kHz, it's not even technically 32,000 kHz.

The sampling frequency is almost assuredly spec'd at 32 kHz. However, the SNES probably uses a low quality clock that, in this case, is 0.125% out of spec. Is the 32.040 kHz sampling frequency your measurement on your specific SNES sample? Or is it a measurement that someone else has posted online?


AJ
 

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Quote:
Originally Posted by zedrein /forum/post/19521058


So in the case of a receiver, like the Pioneer 9140, that says it can take 32 kHz-192 kHz that means that anything in between those sample rates can be decoded? So it can be really awkward like 56,000 kHz and still be decoded and amplified because it falls in between 32 & 192?

Possibly, but probably not. Most DACs will lock onto the three sampling frequencies noted in my first post. Some DACs may be able to accommodate other non standard rates, while some DACs may not. If the SNES truly does output at 32.040 kHz, I suspect that would still be w/in the PLL tolerance of many DACs.


AJ
 

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Quote:
Originally Posted by ap1 /forum/post/19521171


No this is wrong assumption. Normal range is 44, 48, 88, 96, 176, 192. 32kHz may or may nor work, but do not count on it too much.

Nope. Your assumption, too, is wrong. The "normal" rates are 32 kHz, 44.1 kHz, and 48 kHz. Nearly all DACs going back 20 years support these three sampling frequencies. More recently, most newer DACs have added support for higher sampling rates, starting w/ 88.2 kHz & 96 kHz, increasing to 176.4 kHz & 192 kHz.


AJ
 

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Discussion Starter · #9 ·

Quote:
Originally Posted by WiWavelength /forum/post/19521599


The sampling frequency is almost assuredly spec'd at 32 kHz. However, the SNES probably uses a low quality clock that, in this case, is 0.125% out of spec. Is the 32.040 kHz sampling frequency your measurement on your specific SNES sample? Or is it a measurement that someone else has posted online?


AJ

You can see here that the person who measured the SNES output noticed it was at 32,040 Hz and not 32,000 Hz...(it's at the bottom of the page).
 

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Quote:
Originally Posted by zedrein /forum/post/19520862


Hello all. I am razor close to purchasing a new receiver but one aspect that most intrigues me is if new receivers will accept weird digital formats. For example: I modify alot of old video game consoles to have modern capabilities, one of those consoles, the Super Nintendo Entertainment System, is capable of outputting digital audio with a little bid of soldering, but the format it sends the signal is at 16-bit 32,000 kHz, which is different than the standard 16-bit 44,100 kHz. Most new receivers I see out there claim to be 20 Hz-20 kHz, but that doesn't necessarily mean that it will accept a weird non-standard rate...can you all help me to know which specs to look for to know for sure that the receiver is capable of decoding strange signals?


So have you already modified a SNES? And if so have you connected it digitally to your current receiver?
 

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Discussion Starter · #11 ·

Quote:
Originally Posted by afrogt /forum/post/19525579


So have you already modified a SNES? And if so have you connected it digitally to your current receiver?

Well that's the problem, I currently don't own an AV receiver and I need to know which specs specifically to read so I don't buy something that's not as useful to me. I need a decoder that will be able to read a weird sampling rate like 32,040 Hz otherwise I'll have wasted muh money.
 

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Quote:
Originally Posted by zedrein
You can see here that the person who measured the SNES output noticed it was at 32,040 Hz and not 32,000 Hz...(it's at the bottom of the page).
Again, that is just deviation from a perfect clock and is specific to each SNES unit. Note that the measurer says "my SNES," as in "...my SNES is outputting samples at about 32040Hz." Your SNES unit could output at exactly 32 kHz or 29.995 kHz or 32.025 kHz, for example, depending upon the accuracy of its clock.


AJ
 

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I'm not sure if this is helpful, but I looked up the manual for the DAC in my receiver. http://www.wolfsonmicro.com/document.../en/WM8728.pdf


From page 17:
Quote:
The master clock for WM8728 can range from 128fs to 768fs, where fs is the audio sampling frequency (LRCIN) typically 32kHz, 44.1kHz, 48 kHz, 96kHz, or 192 kHz. The master clock is used to operate with digitial filters and the noise shaping circuits.


The WM8728 has a master clock detection circuit that automatically determines the relationship between the mast clock frequency and the sampling rate (to within +/- 32 system clocks). If there is a greater than 32 clocks error, the interface shuts down the DAC and mutes the output. The master clock should be synchronized with LRCIN, although the WM8728 is tolerant of phase differences or jitter on this clock. See table 1

Table 1 shows that a master clock rate of 8.192 MHz (the clock rate from the original article) and a sampling rate of 32kHz means the clock ticks at 256 times the sampling rate.


EDIT: I can confirm that my receiver will handle at least some sampling rates beyond the ones listed above, including 88.2 and 176.4 (using my ps3 to upsample), so it is not an exhaustive list.
 

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Discussion Starter · #17 ·

Quote:
Originally Posted by M Code /forum/post/19526428


Why not take your Nintendo (32kHz) device to an audio store, connect it up and see if it decodes properly..


Just my $0.02...
Quote:
Originally Posted by busky2k /forum/post/19527097


I seriously doubt that there would be any quality increase using a digital transport from the SNES to the receiver. No point pulling your hair out for it! Does the output even conform to S/PDIF?

The problem is there are no brick and mortar stores locally that carry high end AV receivers (as you can imagine, I live in a very small town). So I am going to have to buy a unit online thus I need to know which specs are going to affect me in my quest to mod my SNES. Busky, you have to realize that Nintendo was using DAC's from 1989 to convert the digital audio signal into analog, you can imagine that DSP's nowadays are much better for significantly cheaper and YES, the chip used in this mod reformats the raw digital audio from the SNES into the S/PDIF format. Plus I've read the testimonials from people that have actually performed this mod and they unanimously agree that it's well worth it, no more 60 Hz hum, all the highs, mids, and lows are much richer and more articulate. Besides, aren't we all audiophiles here? I don't think it's a strange obsession to pursue tapping the best possible signal from one of the most highly regarded audio chips in gaming history, I love the Super NES and I love crystal clear audio, it only makes sense.
 
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