DSD only using DSC 1,2 or 3?

[bibo01]

To integrate NAA what are we talking about? Have a ethernet input on the DAC?

I think that a few such interfaces (probably XMOS based) will be introduced on the market soon. One of them will be by Regen, another one (of a different type) will be by JLSounds.

So they will have to be integrated in the DSC2 once they become available.

If, one the other hand, people are thinking of integrating a Cubox (or similar ARM based board, like a Hummingboard) as NAA, it will be up to the single user, given the DIY nature of the project.

 

BTW, JLSounds' USB interface is excellent especially with double separate power supplies. In its latest incarnation it has good NDK clocks, or it can still have its own reclock board. It is supposed to do native DSD256 under Linux and Miska is looking at it. We at Nexthardware.com are testing this new version again at the moment.

 

To have balanced output Miska has indicated to double the circuit boards.

 

Given the type of license, it seems to me that DSC2 will remain a DIY kind of project. It cannot be a finished product.

[Miska]

I'm having such great success isolating my digital noise from the DAC by using a Corning optical USB + regen that while you always could internally connect an ARM board to the USB input via a connector, I'm not personally interested in doing that.

 

I'm using iFi iUSB with DSC1 with very good results, since the Amanero board doesn't have isolation.

 

I could have put isolation on the DSC1 board, but for it to be useful it would have required adding external clocks. And for that to be useful, it would have required modification to the Amanero because external clocks are currently master clocks and DSD doesn't need or use master clock except with traditional DAC chips. Only at DSD512 there would be 1:1 clock ratio using 22.5792/24.476 MHz clocks, but the clock phase also needs to be correct...

 

Thus, for best possible performance with DSD, the USB interface would need to be redesigned. As long as it is primarily designed for PCM using I2S and traditional DAC chips, it is not optimal for a true DSD DAC.

[4est]

Thanks for the update on the JL boards. How do the new iterations compare to the Amanero? I have not been impressed with my Amanero. It could be another issue.

 

I agree on your take, this is DIY. I do not intend pressure on Miska, but to relieve some. He also does not seem like the type to spoon feed. There are associated modules that might work with this. We can save replications and use what is available. Of course, if he decides to do it all I am all for it. Jussi is likely the most universally qualified person on this sight. I paid attention to his posts long before I understood what HQPlayer was all about.

To integrate NAA what are we talking about? Have a ethernet input on the DAC?

I think that a few such interfaces (probably XMOS based) will be introduced on the market soon. One of them will be by Regen, another one (of a different type) will be by JLSounds.

So they will have to be integrated in the DSC2 once they become available.

If, one the other hand, people are thinking of integrating a Cubox (or similar ARM based board, like a Hummingboard) as NAA, it will be up to the single user, given the DIY nature of the project.

 

BTW, JLSounds' USB interface is excellent especially with double separate power supplies. In its latest incarnation it has good NDK clocks, or it can still have its own reclock board. It is supposed to do native DSD256 under Linux and Miska is looking at it. We at Nexthardware.com are testing this new version again at the moment.

 

To have balanced output Miska has indicated to double the circuit boards.

 

Given the type of license, it seems to me that DSC2 will remain a DIY kind of project. It cannot be a finished product.

[4est]

Do you know of a USB board that is optimized for DSD, and how does it differ?

I'm using iFi iUSB with DSC1 with very good results, since the Amanero board doesn't have isolation.

 

I could have put isolation on the DSC1 board, but for it to be useful it would have required adding external clocks. And for that to be useful, it would have required modification to the Amanero because external clocks are currently master clocks and DSD doesn't need or use master clock except with traditional DAC chips. Only at DSD512 there would be 1:1 clock ratio using 22.5792/24.476 MHz clocks, but the clock phase also needs to be correct...

 

Thus, for best possible performance with DSD, the USB interface would need to be redesigned. As long as it is primarily designed for PCM using I2S and traditional DAC chips, it is not optimal for a true DSD DAC.

[jabbr]

 

Given the type of license, it seems to me that DSC2 will remain a DIY kind of project. It cannot be a finished product.

 

Well its open hardware so you could distribute a product that complies with the open hardware license, and if you wanted to use a different license you could approach Miska.

[ted_b]

This would be relatively simple to add, but there's no I2S on the DSC1 since I2S is a PCM interface...

 

My Rendu's I2S does both native (raw) DSD or DoP (depending on Minimserver setting) into the PSA Diretstream, so that is why I asked. Clearly that same re-engineered HDMI interface (I2S) would need to be used, not the standard PCM one Miska references.

[jabbr]

My Rendu's I2S does both native (raw) DSD or DoP (depending on Minimserver setting) into the PSA Diretstream, so that is why I asked. Clearly that same re-engineered HDMI interface (I2S) would need to be used, not the standard PCM one Miska references.

 

Is the interface proprietary or published? In the same way that the Amanero board is used for USB input, there would likely need to be an available board or published circuit that implements the HDMI I2S interface.

[jabbr]

For example, would this work? ºÍ§Ó­µ响

[ted_b]

Is the interface proprietary or published? In the same way that the Amanero board is used for USB input, there would likely need to be an available board or published circuit that implements the HDMI I2S interface.

 

I would get the board from Sonore (Jesus you there? ) They use them to test all iterations of HDMI/I2S inputs to DACs (PSA, Wyred, Rokna, etc). I'd think you'd need to come from a Rendu though (for this board to be available and workable). I would wait for a DSC2 in all probability; do it once, do it right.

[wisnon]

Is the interface proprietary or published? In the same way that the Amanero board is used for USB input, there would likely need to be an available board or published circuit that implements the HDMI I2S interface.

 

PS Audio HDMI standard interface allowing LVDS i2s... Check the Sonore SSR thread here (comments section) for details.

 

Blurb here:

 

The I2S output uses an LVDS transmitter that has an order of magnitude lower jitter than what is found in other LVDS I2S outputs. This is critical for I2S since the master clock is sent over the interface.

 

 

Can you elaborate on what these signals are?

 

 

The LVDS i2s output on the Rendu series is made up of a bit clock, word clock, serial data, and master clock. Not all devices use the master clock. For example, the Raleigh Audio RAKK DAC and the PSA PWD MKI and MKII utilize the Rendu's master clock while the PSA DS DAC and the W4S DAC -2 do not use the Rendu's master clock. LVDS stands for Low Voltage Differential Signal and it's a balanced transmission method for sending TTL level i2s over a cable to a DAC . TTL stand for Transistor-Transistor Logic. Here is the Phillips Semiconductor - i2s Bus Specification https://www.sparkfun.com/datasheets/...rds/I2SBUS.pdf. I'm not sure if it's the latest and the specification does not cover LVDS i2s transmission.

 

https://www.sparkfun.com/datasheets/BreakoutBoards/I2SBUS.pdf

 

PS Audio I2S pinout.pdf

[Miska]

My Rendu's I2S does both native (raw) DSD or DoP (depending on Minimserver setting) into the PSA Diretstream, so that is why I asked. Clearly that same re-engineered HDMI interface (I2S) would need to be used, not the standard PCM one Miska references.

 

I'm happy to hear about pin-out that would have DSDL, DSDR and BCLK signals... Those are all I need. WCLK (aka LRCLK) and MCLK are not relevant for DSD.

 

But overall correct setup would be to have DAC sending MCLK (for PCM) and BCLK (for DSD) to the interface and not like the PS Audio setup. And then there needs to be a control line form interface to the DAC to select which clock to use. (this is how Amanero external clocking works, except it lacks ability to take DSD BCLK in)

[Miska]

Do you know of a USB board that is optimized for DSD, and how does it differ?

 

Unfortunately not. The difference would be to omit the master clock signal and it would accept external BCLK input instead and be able to request necessary different BCLK clocks. For example Amanero and JLSounds could be modified to work like this.

 

With I2S clocking scheme, the MCLK doesn't need to be in phase with the data lines and clocks. Modern DAC chips use MCLK to drive their operations. While older ladder DACs like PCM1704 don't need MCLK at all (because they don't have internal DSP), they latch data based on WCLK. And raw DSD DACs use BCLK instead to latch.

 

So different types of DACs have different jitter-critical clocks:

- D-S DAC chips like Sabre are criticial to MCLK, so MCLK generation should be at the DAC side of isolation

- R2R DAC chips like PCM1704 are critical to WCLK, so WCLK generation should be at the DAC side of isolation

- DSD DACs are critical to BCLK, so BCLK generation should be at the DAC side of isolation

This incidentally also means that the relevant clock generator should be as close as possible to the conversion stage.

[Miska]

Thanks for the update on the JL boards. How do the new iterations compare to the Amanero? I have not been impressed with my Amanero. It could be another issue.

 

My experience has been that you can improve performance of Amanero by using iFi iUSB. But it still depends on how the board is configured in the particular DAC.

[Miska]

What about SDIF3... ?

 

It is closer, but it is still really strange interface format because it runs data over phase modulation (to combine data and bit clock) and then runs 44.1 kHz word clock for synchronization (to be compatible with traditional studio word clock signals).

[bibo01]

I suppose that also this usb interface has the same characteristic/problems of an Amanero:

AKDesign

Right?!

[lightminer]

I think this would be great.

 

For my list of features I'd like to see:

 

1) a DSD-optimized board/process

2) Maybe it could even *only* play DSD-256, not sure if that helps.

3) If it is going to be balanced, then imo it should be full dual-mono all the way through, not just adding an output transformer or whatever stopgap. Heck, at these prices why not make the balanced version full mono separate chassis, like with amps. That would be fun.

4) The NAA with some isolation/buffering/reclocking to make it independent of downstream source quality.

5) To keep costs of production down why not partner with a linear power supply mfg and let them do that part. Like this:

http://www.mains-cables-r-us.co.uk/21-power-supplies

or Teddy Prado or something. Or at least have a cheap default, but put the connector in so those who want an external linear power supply can do it simply by plugging it in.

 

I'd buy that in 2 seconds just to play with in addition to what I have now.

 

If we get a spec lots of people like, any chance Small Green Computer could sell a limited run?

[lightminer]

Here is a ready-made isolator/reclocker device, but not sure how compatible.

 

https://sites.google.com/site/ackodac/home

Look for

AKL-S03 Digital Isolator & Re-clocker

[vortecjr]

I'm happy to hear about pin-out that would have DSDL, DSDR and BCLK signals... Those are all I need. WCLK (aka LRCLK) and MCLK are not relevant for DSD.

 

But overall correct setup would be to have DAC sending MCLK (for PCM) and BCLK (for DSD) to the interface and not like the PS Audio setup. And then there needs to be a control line form interface to the DAC to select which clock to use. (this is how Amanero external clocking works, except it lacks ability to take DSD BCLK in)

 

I have two solutions that can output DSDL, DSDR and BCLK.

 

Solution #1 is a high quality USB to i2s interface that supports up to DSD512 playback. Sonore DIY USB Interface - USB to i2s interface

 

Solution #2 is the standard Rendu with i2s option and the Signature Series Rendu. Both support up to DSD512 playback. Since this is an external source I made up a receiver module to convert the LVDS signals back to TTL level.

 

Neither solution supports bit clock input as is. With USB you can use HQ Player and with the Rendu series you can only play native DSD streams via DLNA.

 

Jesus R

[4est]

I may have botched the firmware as well...

My experience has been that you can improve performance of Amanero by using iFi iUSB. But it still depends on how the board is configured in the particular DAC.

[jabbr]

I have two solutions that can output DSDL, DSDR and BCLK.

 

Solution #1 is a high quality USB to i2s interface that supports up to DSD512 playback. Sonore DIY USB Interface - USB to i2s interface

 

Solution #2 is the standard Rendu with i2s option and the Signature Series Rendu. Both support up to DSD512 playback. Since this is an external source I made up a receiver module to convert the LVDS signals back to TTL level.

 

Neither solution supports bit clock input as is. With USB you can use HQ Player and with the Rendu series you can only play native DSD streams via DLNA.

 

Jesus R

 

So might you supply the module that converts LVDS to TTL with the board? (Native DSD with HQPlayer is a requirement)

[Miska]

5) To keep costs of production down why not partner with a linear power supply mfg and let them do that part. Like this:

Linear Power Supplies from Mains Cables R Us - MCRU

or Teddy Prado or something. Or at least have a cheap default, but put the connector in so those who want an external linear power supply can do it simply by plugging it in.

 

DSC1 already comes with a separate linear PSU board you can put in a separate box, like I do. It has five different power rail outputs; +-12V, 2x 5V and 3.3V. But naturally one can use some other PSU that outputs same voltages...

[Miska]

I suppose that also this usb interface has the same characteristic/problems of an Amanero:

AKDesign

Right?!

 

I'm not sure what you are referring to here? When Amanero works, I have not noticed any major problems with it.

[vortecjr]

So might you supply the module that converts LVDS to TTL with the board? (Native DSD with HQPlayer is a requirement)

 

The USB board already outputs TTL level i2s. The converter module is only needed with the Rendu series as the source.

 

Jesus R

[jabbr]

The USB board already outputs TTL level i2s. The converter module is only needed with the Rendu series as the source.

 

Jesus R

 

I mean to enable an HDMI/I2S/LVDS input to the DSC1, alongside the USB input ... in your Solution#1, the USB -> I2S board could presumably replace the Amanero USB -> I2S board which currently provides the DSDR/L and BCLK inputs to the DSC1. Sitting alongside this could be the "receiver" module you refer to above which could provide the same DSDR/L and BCLK signals.

[vortecjr]

I mean to enable an HDMI/I2S/LVDS input to the DSC1, alongside the USB input ... in your Solution#1, the USB -> I2S board could presumably replace the Amanero USB -> I2S board which currently provides the DSDR/L and BCLK inputs to the DSC1. Sitting alongside this could be the "receiver" module you refer to above which could provide the same DSDR/L and BCLK signals.

 

The hardware is set up for one input. You don't want to switch between these signals because the result is degradation in the signal quality.

 

BTW even with pre-assembled broads this is still a pretty big project and adding more features will only complicate things further.

 

Jesus R