CXA8042 on the Sony DVP-S9000ES

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Hi all:

I tried to install the LCaudio Zapfilter mk2 on the DVP-S9000ES last night. I found that this DVDP using the CXA8042AQ. Ofcoz I cant find any datasheet for it. But I've got some info about this. I follow the info and replace the 1.5K resistor on the pin19 to 3K which for adjust the output current of the DAC...

Then I tried to connect the output direct to the Zapfilter in the current in mode. It cant work..... actrally I found that there have 4V output from the positive and netgative from the output of the CXA8042... and the zapfilter have 8.2V-8V output......

Then I tried to add on the 10ohms bewteen the output of the 8042 to the zapfilter.. also cant work.... when I connect the 8042 back to the I/V of the 9000ES... it becomes normal again...

Question is how can I using the direct output to the zapfilter working at the current input mode? Is there have some tweak or special connection of this to zapfilter?

Actrally I tried to connect the input to the zapfilter share with the I/V satge.. it is not enough gain and seems cutoff the bass..... Any solution on this.... Or I have to connect this in voltage mode after the I/V stage from the 9000ES to zapfilter?

I know it will work but it is not the best way to use the zapfilter.... please advise. Thanks!:confused:
I have also tried to connect ZAPFilter MKII to my Sony-9000ES but with no luck so far.

I have been thinking that maybe it could be possible to connect the ZAPFilter to the IC105 CXD9556AQ but I dont have any data sheets for that Chip.

The only thing I know about the chip is that its an D/A Converter and digitalfilter. It converts everything to DSD (PCM also).

What is a Current pulse D/A (CXA8042AS)???

I have sent scematic of the DAC / Output stage to LCAudio about 3 months ago but I havent recieved any answer from them.

Actrally I just know some info of the CXA8042.... if any fulse on it please forgive.....

I checked some of the Sony CDP and SACDP like 55ES, 777ES(SACD), 555ES(SACD), 9000ES(SACD).... also find that they seems using the same DAC.... As I know all of the Sony DAC network is covert the signal to the pulse which just like the method of the SACD... That's why some guys saying the SACD is not the new Tech.... On the CDP must have the one of the chip call " Pulse convertor" That means they have to change the signal to the current pulse format to their DACs...

But when I saw the installation instruction on the LCaudio about zapfilter on the 50ES.... I suddently think maybe their output just like the simple current DAC.... When I follow the circuit of their DAC... I found that they are all output in balance mode then each phase have the seperate I/V stage... after that go to the filter and join the signal again....

So... I think if we cannot connect it directly from the DACs.... maybe we can connect the signal after the I/V stage.... ofcoz must be working at the voltage mode for the zapfilter... and you will found that maybe the output will be little bit over... so we have to replace the the resistors at the CXA8042AQ pin19 to the 3K0. Lcaudio said it using as the output limit... replace the higher value resistance to make the output lower and have the better offset....

Yes! They're right! I found this resistor in the same value in the Sony CDP which using the their DACs....

But I still dont know why even I replace the resistor still have the 4V at the output stage when the DAC stand alone.... and I wounder is it need some of the network connection to zapfilter to reduce the voltage?!

Unlucky that we cannot find the datasheet for this 8042AQ.... So cant completely understand how it working.... even I still dont know how to idenitfy the phase of the DAC..... Just try it out only.....

So hope someone can have the kindly help on this.... or have to connect the zapfilter after the I/V stage only!!:(
Zapfilter on the 9000ES
I installed the zapfilter on the 9000ES with the voltage mode, the
improvement just make me suprise.... Full range have the very good extensionand very balance... bass extend to the very deep level and the bandwidth of the full range have the improvement too! Actrally I tried to replace the I/V opamps to the OPA2604(Top model of the Burrbrown Dual opamp) have more 15% improvement of the blackground noise... and provide more detail on it.. funny that the sound have little warmer..

Then I tried the AD825 modules from the LCaudio. Crazy extention and the sound more clear and transparent... more 15% improve from the OPA2604....

I still waiting for the replay from the LCaudio for the solution of the current mode.. and still dont know what's wrong with the DAC current output..... I think they maybe have the special network before input to the zapfilter...
This is taken from LC Audios home page

The filter used is a second order Linkwitz-Reilly made with high grade (Unmagnetic) Poly Propylene capacitors from Vishay International. The cutoff frequency is set to 102 kHz for maximum overtone transparency and 100% compatibility with the host CD.
Zapfilter on the 9000ES

It is not at all clear what is said. If the Zap lets through everthing to 100 kHz, then it may well fry tweeters on SACD which is very energetic above 22kHz, the CD cut off frequency.

On CD, a cut off well over 22kHz will allow refelctions back into the audible frequency range and cause intermodulation.

LC needs to explain what the text means, and where the filter starts to roll off.

For you information I have the ZAP but WILL not use it on SACD until I know its characteristics.
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