What's the best DAC digital interface possible?

[Blizzard]

Yes a different multichannel DAC where all channels shared the same master would be best. I'm just talking about what's possible with what you have already since it has that port. But yes it would take remapping the FPGA for support.

Actually it looks like I may be wrong about that. It appears they are using LVDS receiver chips, instead of connecting direct into the I/O bank of the FPGA. Unless those chip are for ESD protection. It's not as good of a way to do it. Those chips add jitter. The Spartan 6 FPGA can be programmed as a direct LVDS receiver and sender. That's the best way to do I2S over LVDS. It also makes it possible to remap to send data out as well as in.


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[edorr]

Actually it looks like I may be wrong about that. It appears they are using LVDS receiver chips, instead of connecting direct into the I/O bank of the FPGA. Unless those chip are for ESD suppression. It's not as good of a way to do it. Those chips add jitter. The Spartan 6 FPGA can be programmed as a direct LVDS receiver and sender. That's the best way to do I2S over LVDS. It also makes it possible to remap to send data out as well as in.

You should chat with TEd Smith. Way beyond me. I don't really care one way or the other as long as I get good sound. I did discuss a MCH version with Paul / Ted though.

 

[BobShermanEsq]

Actually it looks like I may be wrong about that. It appears they are using LVDS receiver chips, instead of connecting direct into the I/O bank of the FPGA. Unless those chip are for ESD protection. It's not as good of a way to do it. Those chips add jitter. The Spartan 6 FPGA can be programmed as a direct LVDS receiver and sender. That's the best way to do I2S over LVDS. It also makes it possible to remap to send data out as well as in.


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I am really sorry but this is just too funny... You are looking at a picture of the board and saying... " It's not as good of a way to do it. Those chips add jitter" WOW... Can't make this stuff up...

 

[BobShermanEsq]

You should chat with TEd Smith. Way beyond me. I don't really care one way or the other as long as I get good sound. I did discuss a MCH version with Paul / Ted though.

Are you sure you are getting good sound??? Hard to imagine after looking at that picture!

 

[cjf]

c..

I can't imagine anyone wanting to use an SD Card as their primary source for very long. For one, SD Cards have a limited lifespan when it comes to heavy Write activity directed at them. If someone had to continually Add/Remove data from them due to their limited storage capacity I could see the cost of replacing those cards getting old in a hurry. This would be especially true if you used one of the previously mentioned large capacity SD Cards which are not cheap by any means.

Then there is the other issue of wear and tear on the wafer board and connections that support the SD Card interface. Having to swap cards out over and over again will take its toll on those hardware components and I would imagine the Users patience if needing to perform that exercise on a frequent basis.

I guess if you feel the difference is big enough to deal with an SD card then your a better man then me but I have my doubts that its much better then a properly setup, low powered media server using USB. At this level we are well beyond splitting hairs.

Would you be bold enough to claim that you could hear a difference with a blindfold on using the SD Card over, I say again, a properly implemented USB connection? Unfortunately, I think I know your answer to this one already

 

[Blizzard]

I am really sorry but this is just too funny... You are looking at a picture of the board and saying... " It's not as good of a way to do it. Those chips add jitter" WOW... Can't make this stuff up...

Helps when you actually have experience using them. Look familiar?

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[Blizzard]

I can't imagine anyone wanting to use an SD Card as their primary source for very long. For one, SD Cards have a limited lifespan when it comes to heavy Write activity directed at them. If someone had to continually Add/Remove data from them due to their limited storage capacity I could see the cost of replacing those cards getting old in a hurry. This would be especially true if you used one of the previously mentioned large capacity SD Cards which are not cheap by any means.

Then there is the other issue of wear and tear on the wafer board and connections that support the SD Card interface. Having to swap cards out over and over again will take its toll on those hardware components and I would imagine the Users patience if needing to perform that exercise on a frequent basis.

I guess if you feel the difference is big enough to deal with an SD card then your a better man then me but I have my doubts that its much better then a properly setup, low powered media server using USB. At this level we are well beyond splitting hairs.

Would you be bold enough to claim that you could hear a difference with a blindfold on using the SD Card over, I say again, a properly implemented USB connection? Unfortunately, I think I know your answer to this one already

It's an option for those who want the best sound quality. As I've mentioned several times, what about vinyl, cd's and reel to reel? People still use them. I'm not saying it absolutely must be your only source of transport. You can still use whatever you want. But when you want the best sound, use this.

Do wear issues not apply to vinyl, CD players and R2R? At least there's no moving parts. The cost of the reader is $2.47. If it ever wears out its a 2 minute job to replace.

I could pick it out blindfolded in a heartbeat. The difference is substantial.

 

[cjf]

It's an option for those who want the best sound quality. As I've mentioned several times, what about vinyl, cd's and reel to reel? People still use them. I'm not saying it absolutely must be your only source of transport. You can still use whatever you want. But when you want the best sound, use this.

Do wear issues not apply to vinyl, CD players and R2R? At least there's no moving parts. The cost of the reader is $2.47. If it ever wears out its a 2 minute job to replace.

I could pick it out blindfolded in a heartbeat. The difference is substantial.

I see!

So what kind of cable are you using between the SD Card Reader and the SD Card Slot? I find it interesting that you are willing to trust a $2.47 contraption to live between such a critical link in the system. Maybe additional veils could be lifted if you went straight to the board with the SD Card instead

 

[Blizzard]

I see!

So what kind of cable are you using between the SD Card Reader and the SD Card Slot? I find it interesting that you are willing to trust a $2.47 contraption to live between such a critical link in the system. Maybe additional veils could be lifted if you went straight to the board with the SD Card instead

It's actually has high quality gold plated connections. It only has to travel 1/4" down high purity copper PCB traces before the data makes it to the DAC FPGA. From there it's buffered into the RAM chip, and synchronically clocked to the DAC master and straight into the DAC chip. If you know of a purer, less jitter way to transmit data please share.

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[cjf]

It's actually has high quality gold plated connections. It only has to travel 1/4" down high purity copper PCB traces before the data makes it to the DAC FPGA. From there it's buffered into the RAM chip, and synchronically clocked to the DAC master and straight into the DAC chip. If you know of a purer, less jitter way to transmit data please share. ]

But it seems your leaving out the $2.47 card reader in your chain of connections above. Doesn't the SD card plug into said card reader first and the reader then plugs into the SD Slot on the motherboard? This whole time here I thought your were hard core, but I'm a bit disappointed to see this card reader involved. Have you tried the SD card directly in the slot on the motherboard without the reader?

How do you know this reader isn't contributing to packet errors or timing related Jitter? It is after all an added length of stuff that needs to be traversed before making it to the original slot on the board.

At least with Ethernet and USB you can be sure those sort of issues are corrected. A $2.47 card reader, not so much!

 

[Blizzard]

But it seems your leaving out the $2.47 card reader in your chain of connections above. Doesn't the SD card plug into said card reader first and the reader then plugs into the SD Slot on the motherboard? This whole time here I thought your were hard core, but I'm a bit disappointed to see this card reader involved. Have you tried the SD card directly in the slot on the motherboard without the reader?

How do you know this reader isn't contributing to packet errors or timing related Jitter? It is after all an added length of stuff that needs to be traversed before making it to the original slot on the board.

At least with Ethernet and USB you can be sure those sort of issues are corrected. A $2.47 card reader, not so much!

I'm not rewriteing the whole thread again. I already posted a detail explanation of how the reader streams the data off the card. It was specifically programmed to send the data smoothly to avoid the packet noise general purpose computer CPU's and USB interfaces create.

Timing related jitter?? The data isn't even clocked until it reaches the RAM chip. From there it gets converted to I2S/DSD streams and straight down PCB traces to the DAC chips.


Your gonna have to bring more than a cap gun to this showdown if you have any hopes of proving anything. Because I've actually done my homework.

How much do you think those USB receptacles cost on the back of your DAC. Maybe 2-3 cents in volume.

This is "What's best forum", not "Whats mediocre forum" and this thread is called "What's the best digital interface possible" so if you have a problem with doing things the best way, this may not be the best place for you. If you don't, show us a better way, or stop criticizing great engineering.

Same goes for Bob.

 

[BobShermanEsq]

Helps when you actually have experience using them. Look familiar?

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But still any sane person would understand it presumptuous. There is so much more that goes into design. It s easy to say things... but a hobbyist playing with chips does not make you Frito-Lay...

 

[cjf]

The data isn't even clocked until it reaches the RAM chip. From there it gets converted to I2S/DSD streams and straight down PCB traces to the DAC chips.

Lol..this is pretty entertaining!

So based on what you say above, why would the DAC Chip care which method was used to transport the 1's & 0's to the RAM chip? If its ALL getting buffered and re-clocked before it reaches the DAC then it doesn't matter how it got there so the "superior" SD Card approach is pointless and couldn't be responsible for your SQ increases. This only leaves us with with combating noise/grunge in this whole debate then.

 

[BobShermanEsq]

I'm not rewriteing the whole thread again. I already posted a detail explanation of how the reader streams the data off the card. It was specifically programmed to send the data smoothly to avoid the packet noise general purpose computer CPU's and USB interfaces create.

Timing related jitter?? The data isn't even clocked until it reaches the RAM chip. From there it gets converted to I2S/DSD streams and straight down PCB traces to the DAC chips.


Your gonna have to bring more than a cap gun to this showdown if you have any hopes of proving anything. Because I've actually done my homework.

How much do you think those USB receptacles cost on the back of your DAC. Maybe 2-3 cents in volume.

This is "What's best forum", not "Whats mediocre forum" and this thread is called "What's the best digital interface possible" so if you have a problem with doing things the best way, this may not be the best place for you. If you don't, show us a better way, or stop criticizing great engineering.

Same goes for Bob.

Congratulation! On being promoted to moderator.

Amir, please place this in his title so can all be aware.

Can we say Hubris!!!

And no this is not meant to be a racial slur directed toward the ancient Greeks. Lol

 

[Blizzard]

Lol..this is pretty entertaining!

So based on what you say above, why would the DAC Chip care which method was used to transport the 1's & 0's to the RAM chip? If its ALL getting buffered and re-clocked before it reaches the DAC then it doesn't matter how it got there so the "superior" SD Card approach is pointless and couldn't be responsible for your SQ increases. This only leaves us with with combating noise/grunge in this whole debate then.

1acket noise is reduced using this method,

2:There's a smoother more constant draw of electricity from the LDO's which results in less noise.

2: Reclocking isn't required, because the data isn't even clocked until it reaches the FPGA. Reclocking is better than jittery data, but it's not as good as a single clean clocking.

3: far superior algorithms are used to decode compressed PCM formats.

4: no noise is transmitted from external sources, because there isn't any connected.

 

[Blizzard]

But still any sane person would understand it presumptuous. There is so much more that goes into design. It s easy to say things... but a hobbyist playing with chips does not make you Frito-Lay...

Maybe you should call Larry at MSBtech up and tell him he's an idiot for switching from that system with their ProI2S upgrade. They claim 10X less jitter.

http://www.msbtech.com/products/pro.php?Page=platinumHome

 

[cjf]

1acket noise is reduced using this method,

And what noise would that be at this level? The values of 1 & 0 are absolute. I'll wait for you to post up your measurements to support this claim

2: Reclocking isn't required, because the data isn't even clocked until it reaches the FPGA. Reclocking is better than jittery data, but it's not as good as a single clean clocking.

Again, if everything is buffered into RAM first then the method used to populate that RAM chip is unimportant assuming the RAM Chip is large enough to hold a few seconds of streamed media data

3: far superior algorithms are used to decode compressed PCM formats.

And how does the use of a SD Card provide a means to do that?

4: no noise is transmitted from external sources, because there isn't any connected.

I'll agree with you on this one as long as your happy with the amount of content at your disposal living on the SD Card

 

[Kal Rubinson]

It is a shame that the SDtrans384 is limited to 32gb SD cards. But still you can fit thousands of albums between 2 fingers.

Not quite. Most of my files run 3-6Gb each.

To add to this, it's not essential that everything is stored on the SD cards. You can always just find what you want to hear on computer before your listening session and transfer it onto the card. Takes far less time than flipping records over and swapping them out each album.

That is the wrong comparison.

BTW, I am not contending with your proposition about the sound quality hierarchy among DAC interfaces because I do not have a wide enough experience. I am limited to devices that will play what I want.

 

[Blizzard]

Not quite. Most of my files run 3-6Gb each.

That is the wrong comparison.

BTW, I am not contending with your proposition about the sound quality hierarchy among DAC interfaces because I do not have a wide enough experience. I am limited to devices that will play what I want.

Yes in the case of the SDtrans384, the 32gb SD card limitation is a bit of a pain. But in reality, even if you can only fit 6 albums of DSD 256 on each card, that still gives you at least 5 hours of audio to listen to before you need to spend the couple of minutes to copy over different tracks. How much time would it take to flip a record over 12 times, swap records, clean off the dust etc?

This is a $450 unit that is capable of of providing the best sounding digital you ever had in your system. I think the pros/cons balance tips in its favor.

Why don't you buy one and try it? It may be a real eye opener. And I'm sure it won't break the bank compared to other transports you've had in your system. But better hurry, I think the latest batch is almost sold out. May be months before the next run.

 

[wisnon]

Have YOU bought one?

How does one go about buying one anyway?