DAC Mod Suggestions?

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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
 

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Flappytango said:
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
 
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??
 
Flappytango said:
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
 
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
 
fastcat95 said:
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
 
Konnichiwa,

Flappytango said:
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
 
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 said:


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
 
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 ......:cool:
 
Re: CS8412 DAC

Elso Kwak said:
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 ......:cool:


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
 
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