DAC Mod Suggestions?

[Flappytango]

Hello All,
Im new to digital tinkering and am trying to get my feet wet playing with this DAC while i get educated.

This is an Entech Number Cruncher 203.2. As you see it has cs8412 and had a cs4329. I swapped it out for fun with a CS4390 and adding a 20pin socket. IT has a OPA2134.

Any thoughts on best place to start for upgrading?? Like which capacitors to replace? I see talk of opamp upgrades and clocks etc.
Im open to all sugestions!
Thanks

 

[Guido Tent]

Hello All,
Im new to digital tinkering and am trying to get my feet wet playing with this DAC while i get educated.

This is an Entech Number Cruncher 203.2. As you see it has cs8412 and had a cs4329. I swapped it out for fun with a CS4390 and adding a 20pin socket. IT has a OPA2134.

Any thoughts on best place to start for upgrading?? Like which capacitors to replace? I see talk of opamp upgrades and clocks etc.
Im open to all sugestions!
Thanks

clock upgrade is a must if you respect all bits.....

Guido

 

[Flappytango]

ok clock ive seen discussion of clock improvement being very rewarding.. ill look into it.

i dont understand how better triggering really allows you to respect the bits?

are those polyester caps worth replacing ? Is it best to do all or will any benefits come from selective replacement??

 

[Guido Tent]

ok clock ive seen discussion of clock improvement being very rewarding.. ill look into it.

i dont understand how better triggering really allows you to respect the bits?

are those polyester caps worth replacing ? Is it best to do all or will any benefits come from selective replacement??

Hi

The bits represent the amplitude. Conversion at wrong moment converts correct amplitude at wrong moment which yields distorrtion, at the end...........

regards

 

[fastcat95]

Hey Flappytango:

Since you have the CS8412 reciever chip, you might want
to try the Wildmonkysect analog filter mod for this chip.
Check out the link for more info on the stock and modified
values of the filter:

http://www.audioasylum.com/audio/tweaks/messages/30297.html
There are always the ideas of improved chip bypassing, better
power supplies, better op-amps (depending on the operation
mode of the DAC- current or voltage output?), better connectors,
better logic gates, etc.

Fastcat

 

[Guido Tent]

Hey Flappytango:

Since you have the CS8412 reciever chip, you might want
to try the Wildmonkysect analog filter mod for this chip.
Check out the link for more info on the stock and modified
values of the filter:

http://www.audioasylum.com/audio/tweaks/messages/30297.html


Fastcat

Hi

this is a great (cheap) upgrade, but does not bring you on the "real low jitter train" ..........

Ciao

 

[Peter Daniel]

Re: Re: DAC Mod Suggestions?

clock upgrade is a must if you respect all bits.....

And how one performs clock upgrade with a board like this? I don't see a clock here.

 

[Guido Tent]

Re: Re: Re: DAC Mod Suggestions?

And how one performs clock upgrade with a board like this? I don't see a clock here.

true, the clock might be the upgrade............

regards

 

[Peter Daniel]

So, you mean adding an extra clock? But where?

 

[ThorstenL]

Konnichiwa,

Im new to digital tinkering and am trying to get my feet wet playing with this DAC while i get educated.

This is an Entech Number Cruncher 203.2.

Any thoughts on best place to start for upgrading??

Sell it as is and build a Sealed Lead Acid Battery powered, TDA1543 based DAC, start with Fedde's ....

http://home.student.utwente.nl/f.s.bouwman/audio/nonoz3.html

Then play with more exterme stuff....

Sayonara

 

[Guido Tent]

So, you mean adding an extra clock? But where?

the 8412 puts out 200ps of jitter, so that needs cleaning up.....

Ciao

 

[Peter Daniel]

There is another option too, if you don't think you'll get much for selling this DAC. You could use input receiver circuitry and connect to it directly TDA1543 chip. In this way you would have already half of the work done and possibly also input switching available.

I'm thinking about similar approach with my Audio Alchemy DAC.

 

[Peter Daniel]

the 8412 puts out 200ps of jitter, so that needs cleaning up.....

Ciao

You have reclocking in mind?

 

[rfbrw]

VCXO/PLL ?

 

[Guido Tent]

You have reclocking in mind?

ofcourse, you know me, nah ?

reclocking in my definition is retiming of existing signal. Generating a new clock is neccessary to retime the signals, and can be done using a secondary PLL circuit (with a LOW cutoff, unlike the 20kHz ion the 8412)

Most important is the clock that actually converts the words, but retiming of ALL signals entering a DAC chip is worth the trouble, like we did

http://members.chello.nl/~m.heijligers/DAChtml/dactop.htm

Ciao

 

[Elso Kwak]

CS8412 DAC

Hi,
The CS8412 likes to be driven differentially and NOT directly from the transmission line.
So my interface with the AD8561 or Freds with 74HCU04 and 74HC86 comes to mind.
Also a low noise ANALOG supply for the PLL of the CS8412 helps as well as the Wildmonkeysects loop filter.
Also my Asynchronous Reclocker might help though I believe it is best to prevent jitter from occuring as with I2S Direct, omitting the CS8412, rather than to cure it with a anti jitter device such as the ASR or an extra PLL after the CS8412. Best replace the masterclock in the transport by a good one. I guess the ......😎

 

[Peter Daniel]

You might check this post I made in Chip Amps section about comparing two DACs: http://www.diyaudio.com/forums/showthread.php?s=&threadid=26001&perpage=15&highlight=&pagenumber=5

I'm not so sure anymore if ASR is something I would consider a must.

 

[Elso Kwak]

Simple DAC better?

You might check this post I made in Chip Amps section about comparing two DACs: http://www.diyaudio.com/forums/showthread.php?s=&threadid=26001&perpage=15&highlight=&pagenumber=5

I'm not so sure anymore if ASR is something I would consider a must.

Hi Peter,
Any clue why the "simple" DAC is better?
I am glad doing one mod at a time......

😕

 

[Guido Tent]

Re: CS8412 DAC

Hi,
The CS8412 likes to be driven differentially and NOT directly from the transmission line.
So my interface with the AD8561 or Freds with 74HCU04 and 74HC86 comes to mind.
Also a low noise ANALOG supply for the PLL of the CS8412 helps as well as the Wildmonkeysects loop filter.
Also my Asynchronous Reclocker might help though I believe it is best to prevent jitter from occuring as with I2S Direct, omitting the CS8412, rather than to cure it with a anti jitter device such as the ASR or an extra PLL after the CS8412. Best replace the masterclock in the transport by a good one. I guess the ......😎

Elso,

Ofcourse a one box design yields the best solution, but if we restrict to external DAC and exoisting interface we have options:

- The industrial way (yuck)
- Idem improved with either good PLL or ASR
- Place masterclock at DAC and feed back that clock to drive
- Idem but still use PLL, place VCXO in drive and feedback control signal
- use SRC

All have their pro's and cons. I am still not happy with ASR as missed samples give distortion.
New SRC's are improving so there is still hope. The main problem remaining is the vast amount of jitter that these devices spit out, so extensive reclocking of all lines is a must.

Ciao

 

[Bas Horneman]

wildmonkeysects loop filter

'3300 picofarad cap from the loop filt pin directly to ground'

Is this cap from pint 21 to ground or from pin 20?

Also is 0.22mfd same as 0,22uF?

Regards,
Bas