TDA1541A - DIR9001 DAC reclock

[UV101]

Hi,

Has anyone reclocked a DAC internally fitted with a TDA1541a and a DIR9001 receiver chip?

I can get my dac to work with an external 11.2896Mhz clock when I use a CS8412 (set to use external clock) but not the DIR9001.

I do not want to use the recovered clock from the SPDIF.

From the datasheet for the 9001, I can see that you can use an external clock (as opposed the the internal PLL recovered clock from the spdif) but it states that the external clock freq should be 24.576Mhz. This frequency is not acceptable to the TDA.

I would like to use the 11.2896Mhz clock I currently use on the dac.




Thanks

Ian

[ThorstenL]

Hi,

Originally Posted by UV101

I can get my dac to work with an external 11.2896Mhz clock when I use a CS8412 (set to use external clock) but not the DIR9001.

The DIR9001 does not offer the slave mode the CS8412 does.

That said, unless you have a clock with very precisely the same clock frequency in your source (as in < 1ppm deviation from nominal) calling this mode "working" is a bit of a stretch.

I have worked with several china sourced DAC's that implement this slave mode and they invariably sound and measure much better once the real problems in their receiver circuitry are fixed and the clock is removed. This includes DAC's with the TDA1541.

Originally Posted by UV101

I do not want to use the recovered clock from the SPDIF.

Then you need to use a system where the DAC's clock is send to the transport. Even secondary PLL's using a VCXO ultimatly use the SPDIF clock.

The best you can do in this day and age using a single chip is to use a WM8805.

Originally Posted by UV101

From the datasheet for the 9001, I can see that you can use an external clock (as opposed the the internal PLL recovered clock from the spdif) but it states that the external clock freq should be 24.576Mhz.

Did you REALLY read the datasheet?

....
· XTI MODE: For clock generator; always outputs XTI source clock
....
Notes about operation mode selection:
· The XTI mode is a mode that supplies the XTI source clock to
peripheral devices (A/D converters, etc); therefore, recovered clock
and decoded data is not output.

In other words, this clock is only to drive AD converters etc., it does not help you. The 24.576MHz clock produces a fixed sample rate of 96KHz BTW.

Originally Posted by UV101

I would like to use the 11.2896Mhz clock I currently use on the dac.

Then you cannot use DIR9001. And as remarked, even with CS8412/8414 this does not really work, unless you have very tight control over the source clock as well.

Ciao T

[Marlowe]

Originally Posted by ThorstenL

Then you need to use a system where the DAC's clock is send to the transport. Even secondary PLL's using a VCXO ultimatly use the SPDIF clock.

Hi Thorsten,

I have a NOS TDA1541A DAC. In the NOS mode, no master clock is needed so that how could I send the master clock to the transport as OS DACs?

[UV101]

The clock signals are recovered/generated in the spdif receiver chip. You could try connecting via I2S (or similar, left justified etc) but its likely that the source will not run the same master clock speed as the TDA DAC. If the transport and DAC run the same clock speed, they could be shared but its not a straight forward task.

I plan to run in I2S from my transport to my DAC (very shot coaxes) as I want to move my S2 TDA from my player leaving more room for Servo PSU's etc. I also wanted to make provision for SPDIF in on the DAC. I will implement a Cirrus receiver in light of the comments from Thorsten (thanks for the info )as I know I can run a clock in the DAC (which will also feed the transport) with this chip. The clock I am using is currently in the dac is a trichord clock 4b but my CDP has an audioupgrades.co.uk C2 clock and a TDA1541a S2 and does not use the external DAC!!

My plan is to make the best dac possible with both SPDIF and I2S inputs and use spdif for my squeezebox and connect the I2S generated from the decoder (SAA7210) from my CDP.

Ian