Asynchronous I2S FIFO project, an ultimate weapon to fight the jitter

[RollE2k]

Yes, the Buff clock is 100MHz CCHD-950.
But then reading the newer DualXO double rate manual it seems as FIFO+XO-board with 45.1584/49.1520 MHz crystals in sync mode seems to be the way to go (since then i would cover all the way from 44.1/48 to 352/384). I'll have to read more about this.
So the reason Buff uses 100MHz clock, must be to cover all samplerates in Async mode, for flexibility that is.

[roender]

Originally Posted by RollE2k

So the reason Buff uses 100MHz clock, must be to cover all samplerates in Async mode, for flexibility that is.

Exactly! In syc mode there is no need for such high frequency clock.

[RollE2k]

So then for me who will use alot of sample-rates and both SPDIF/I2S the best way to use this would be to have my Amanero and a SPDIF->I2S board, connect through a 2:1 switch like Twisted pear OTTO-2, and then into the FIFO, through the XO-board to my DAC.

[hochopeper]

Actually the datasheet recommends >192*FS for OSF Normal mode. (NB greater than and NOT equal to/greater than).

So 45/49 is only good up to 192kHz.

This is at least part of the reason why Ian has gone to great effort for the Si570 as a way of providing the faster clock frequencies!

Chris

[roender]

Originally Posted by hochopeper

Actually the datasheet recommends >192*FS for OSF Normal mode. (NB greater than and NOT equal to/greater than).

So 45/49 is only good up to 192kHz.

This is at least part of the reason why Ian has gone to great effort for the Si570 as a way of providing the faster clock frequencies!

The OSF is off in Sync mode

[hochopeper]

Originally Posted by RollE2k

So then for me who will use alot fo sample-rates and both SPDIF/I2S the best way to use this would be to have my Amanero and a SPDIF->I2S board, connect through a 2:1 switch like Twisted pear OTTO-2, and then into the FIFO, through the XO-board to my DAC.

Actually Ian's Spdif->i2s board has an i2s 'back door' that means you can provide your i2s from amanero through this i2s input on the spdif board and cycle through inputs on that board without any drama of having extra multiplexor boards. Unless you have more than one i2s input? Check the zip file for Ian's spdif manual for instructions.



Chris

[hochopeper]

Originally Posted by roender

The OSF is off in Sync mode

This is a common misconception. The OSF and synchronous clocking are two separate issues.


Chris

[roender]

Originally Posted by hochopeper

This is a common misconception. The OSF and synchronous clocking are two separate issues.

Then how do you explain that I'm able to play PCM 384Khz FS with my BIII connected synchronous with SDtrans384?
I have an dual clock board made by myself based on CCHD957 45.1584 MHz and 49.152 MHz placed on BIII DAC. The clock selection is made remotely by SDtrans

[RollE2k]

Originally Posted by hochopeper

Actually Ian's Spdif->i2s board has an i2s 'back door' that means you can provide your i2s from amanero through this i2s input on the spdif board and cycle through inputs on that board without any drama of having extra multiplexor boards. Unless you have more than one i2s input? Check the zip file for Ian's spdif manual for instructions.

Chris

This would be the best way to run it, but the problem for me is that i probably won't have enough room in my case (DAC will be together with my tube-linestage, w. AMB R-2R volume, input selector, PSU's and everything), so ian's SPDIF board will not fit the case, if it was smaller (like if the outputs were removed, and connectors were offboard) then it would work. I'll probably have to go for TP-4:1 MUX together with OTTO-2. If there isn't any other good alternatives out there.

Robert

[hochopeper]

Originally Posted by roender

Then how do you explain that I'm able to play PCM 384Khz FS with my BIII connected synchronous with SDtrans384?
I have an dual clock board made by myself based on CCHD957 45.1584 MHz and 49.152 MHz placed on BIII DAC. The clock selection is made remotely by SDtrans

ES9012/8 OSF is ON unless explicitly set to OFF by the DAC controller, refer to page 17 of the datasheet.

The datasheet clock recommendations are just that, recommendations for optimal performance, just because they work doesn't mean that the DAC chip is going to perform at its best. Ian has commented (see quote below) in his Si570 reviews earlier that there is differences between 44.1kHz at 45.1584MHz vs 90.xxxxMHz. He would not at the time comment which was his preference, just that they were subjectively different.

Originally Posted by iancanada

4. Another discovery is, ESS9081 sounds different for a same 44.1 KHz stream with different MCLK frequencies, for example 45.1584MHz and 90.3168MHz. Hard to tell which one is better, but the sound style is a bit different indeed. I know it’s the internal up-sampling digital filter, different performance for different MCLK.

Cheers,
Chris