I am a guy posted few months before questioning mods on Arcam CD72. Thank you ergo-san for your help at that moment.
After modding CD72 as my skill preparation,actually that was my career first modding, I did some mods on my Sony CDP-777ESA, pulse DAC w/o current DAC version made in 1991.
I started summarize my mods at:
http://www.cameraguild.jp/123/hifi/777esa/index.html
now in English.
I will soon upload part2 where I added elec caps and film caps to all the opamps' PS pins (total 20 elec cas and 20 film caps).
Any comment or thought on my mods will be highly appreciated, and my particular question here is about opamps.
I have replaced output stage opamps as below and get pretty good sound quality.
1) balanced buffer NE5532P -> AD825x2
2) mix down to single-ended NE5532P(1ch) -> OPA627
3) LPF? NE5532P -> AD847
4) LPF?Driver? AD712 -> AD847+AD797
5) DC servo OPA27 -> no change
Attached image is the situation.
One issue about above combination is click noise at every track search, and between tracks in some CDs.
I already found AD797 is the key to this, and if I replace it with some type of FET opamps like OPA134, click noise disappears.
But I do not like warm round sound of OPA134.
Anyone has a good alternative opamp here or more root countermeasure to reduce click noise?
I am modding without schematic (failed to get it even in Japan), and that's the part of reason of my difficulty. Anyone has it?
Regards,
After modding CD72 as my skill preparation,actually that was my career first modding, I did some mods on my Sony CDP-777ESA, pulse DAC w/o current DAC version made in 1991.
I started summarize my mods at:
http://www.cameraguild.jp/123/hifi/777esa/index.html
now in English.
I will soon upload part2 where I added elec caps and film caps to all the opamps' PS pins (total 20 elec cas and 20 film caps).
Any comment or thought on my mods will be highly appreciated, and my particular question here is about opamps.
I have replaced output stage opamps as below and get pretty good sound quality.
1) balanced buffer NE5532P -> AD825x2
2) mix down to single-ended NE5532P(1ch) -> OPA627
3) LPF? NE5532P -> AD847
4) LPF?Driver? AD712 -> AD847+AD797
5) DC servo OPA27 -> no change
Attached image is the situation.
One issue about above combination is click noise at every track search, and between tracks in some CDs.
I already found AD797 is the key to this, and if I replace it with some type of FET opamps like OPA134, click noise disappears.
But I do not like warm round sound of OPA134.
Anyone has a good alternative opamp here or more root countermeasure to reduce click noise?
I am modding without schematic (failed to get it even in Japan), and that's the part of reason of my difficulty. Anyone has it?
Regards,
Attachments
Very nice webpage you have made 
http://www.lcaudio.dk/com/index.php?page=3
Is what you are looking for
My impression of the module type 3
Its just like "a piece of wire with gain"
http://www.lcaudio.dk/com/index.php?page=3
Is what you are looking for
My impression of the module type 3
Its just like "a piece of wire with gain"
PMik-san,
Thank you for your noticing me a LCaudio page.
Actually, I did buy their AD8065 type2 for my Sony, and after placing an order, I found its max supply voltage is +/-12V, while my Sony provides +/-14V for opamps
Now AD8065s are set into my friend's Arcam CD72 and are proving their performance are better than OPA627 in Arcam's circuitry, just as your saying wire with gain.
Usually, I am buying electronic components at Akihabara in Tokyo. This place is a good place for buying hifi electrolytics, such like BG, OS-CON or Silmic, but rather weak in opamps. I am interested in AD823 or others but not yet have a chance to use them.
My installed AD797 and OPA627 are two big giants here in Japan for diy audio.
Thanks.
Thank you for your noticing me a LCaudio page.
Actually, I did buy their AD8065 type2 for my Sony, and after placing an order, I found its max supply voltage is +/-12V, while my Sony provides +/-14V for opamps
Now AD8065s are set into my friend's Arcam CD72 and are proving their performance are better than OPA627 in Arcam's circuitry, just as your saying wire with gain.
Usually, I am buying electronic components at Akihabara in Tokyo. This place is a good place for buying hifi electrolytics, such like BG, OS-CON or Silmic, but rather weak in opamps. I am interested in AD823 or others but not yet have a chance to use them.
My installed AD797 and OPA627 are two big giants here in Japan for diy audio.
Thanks.
Hi Senshu, I may have the manual as this model looks very similar to the Sony CDPXA7ESA which is again very similar to the Sony CDP-X777ES. Of the latter I also posses the manual.
The best mod you can do is the clock mod I have written many times about. Mail me for the 45.1584 MHz schematic.
You have to cope with the two-clock issue. Please see:
http://db.audioasylum.com/cgi/m.mpl...&highlight=Elso+two+clock+problem&r=&session=
The best mod you can do is the clock mod I have written many times about. Mail me for the 45.1584 MHz schematic.
You have to cope with the two-clock issue. Please see:
http://db.audioasylum.com/cgi/m.mpl...&highlight=Elso+two+clock+problem&r=&session=
oh!!! my god
Senshu .
....Thanks for this notice 
I had negilegted that part
for me Op-Amps = Lego
and should be powered by +- 15~18VDC for dynamic range,
But things has changed i see
The last mod. where i used LC Op-Amps the supply voltage was
below the max. rating ... Pheeew!
Senshu .
....Thanks for this notice I had negilegted that part
for me Op-Amps = Lego
and should be powered by +- 15~18VDC for dynamic range,
But things has changed i see
The last mod. where i used LC Op-Amps the supply voltage was
below the max. rating ... Pheeew!
Attachments
Elso-san,
According to this web page:
http://cdp101.hp.infoseek.co.jp/esseries-main.html (!!!mostly in Japanese),
CDP-X777ES was launched one year before my 777ESA, and the architecture seems to be almost identical except their DACs, X777ES=CXD2552 and 777ESA=CXD2562Q.
Your sending me a manual for CDP-X777ES will be highly appreciated.
Also, thank you for your leading me to Swoboda in Germany.
For me, sticking to utilize Sony's DAC, Swoboda's solution seems to be best. I did immediately send an inquiry e-mail to this firm
I was planning to purchase XO3 clock for simply replacing 45MHz xtal, but there may be some way to use XO3 on Germany board as well, if I find any issue on their solution.
According to this web page:
http://cdp101.hp.infoseek.co.jp/esseries-main.html (!!!mostly in Japanese),
CDP-X777ES was launched one year before my 777ESA, and the architecture seems to be almost identical except their DACs, X777ES=CXD2552 and 777ESA=CXD2562Q.
Your sending me a manual for CDP-X777ES will be highly appreciated.
Also, thank you for your leading me to Swoboda in Germany.
For me, sticking to utilize Sony's DAC, Swoboda's solution seems to be best. I did immediately send an inquiry e-mail to this firm
I was planning to purchase XO3 clock for simply replacing 45MHz xtal, but there may be some way to use XO3 on Germany board as well, if I find any issue on their solution.
777ESA = 779ES
Hi!
I have th CDP-X779ES wich is the non-japanese(?) version of the 777ESA.
I have tried a lot of op-amp swapping, and sofar most happy with AD826 in most places, but the "buffer"op-amp is very sensitive, and found a OP2132 worked ok there. Left the OPA27 alone.
Next challenge is the clock...or clocks.
As there are 2; a 45MHz "master" clock, and a 16MHz special X-tal wich is slaved from the master (from the dac-output marked 128fs).
It seems that Swoboda is the only supplier of a complete syncronized (dual)clock-module for these players.
I find it strange that nobody else have cracked this "sync" issue....
Any suggestions?
Arne K
Hi!
I have th CDP-X779ES wich is the non-japanese(?) version of the 777ESA.
I have tried a lot of op-amp swapping, and sofar most happy with AD826 in most places, but the "buffer"op-amp is very sensitive, and found a OP2132 worked ok there. Left the OPA27 alone.
Next challenge is the clock...or clocks.
As there are 2; a 45MHz "master" clock, and a 16MHz special X-tal wich is slaved from the master (from the dac-output marked 128fs).
It seems that Swoboda is the only supplier of a complete syncronized (dual)clock-module for these players.
I find it strange that nobody else have cracked this "sync" issue....
Any suggestions?
Arne K
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