upgrade a Sony CDP XA7Es / two clock problem in Sony players

Having changed the power chord of my CDP XA7es player to two coax cables
with saftey ground connected to the shields sound quality improved a lot ..it almost reaches my heavily tweaked Kenwood DP 1100SG (built in LC clock, new OPAMPs etc.).
So I think it is very worthwhile to upgrade the clock(s)..has anyone found a solution for upgrading both clocks in this player (or simillar models)?
regards, Philipp
 
I attach the service manual for the cdp xa7es...if you look at the power supply for the analog section (page25)..remarkebly - never saw something like this in a commercial player..
I had a skipping problem after warm up, but it could be easily fixed : I simply plugged/replugged all connectors to the servo board twice ,which are reachable after removing the top plate of the player..
eye pattern level reached the 1.2Vpp after cleaning the lense, with self burnt CDs level is a bit low (~0.8V), but no skipping..
I always check the sound with a Stax 407 with modified SRM T1 amp (replaced the anode resistors by current sources)..
I can recommend the RDC-Puck - more air, smoother sound, better focus..
there are a lot of two clock Sony players out there, so a two clock upgrade should be of interest for many..(Swoboda charges 615€..)
with original power chord I could not stand the harsh,thin sound of this player..I removed all connectors carrying the 230V and directly soldered the wires (bypassed the two fuses with wires..I know, just for the time beeing)..highly recommended
I believe this player has very high hidden potential for sound improvement!
regards, Philipp
 
Having changed the power chord of my CDP XA7es player to two coax cables
with saftey ground connected to the shields sound quality improved a lot ..it almost reaches my heavily tweaked Kenwood DP 1100SG (built in LC clock, new OPAMPs etc.).
So I think it is very worthwhile to upgrade the clock(s)..has anyone found a solution for upgrading both clocks in this player (or simillar models)?
regards, Philipp

I am sorry but to do this is very dangerous, especially to delete the protection fuses as you write about in a later blog.
How can replacing the 230Volt mains supply cable improve the sound unless you have noisy mains supply in which fit a mains filter.
 
Hello, I snapped the fuses back..most main filters actually worsen the sound,
I think because of higher HF current in the safety ground...please see attached paper from Bill Whitlock..
Please let us focus on the two clock problem..
 

Attachments

  • Bill Whitlock on grounding.pdf
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I left the two clocks unchanged, but improved their power supplies..
Well, I did a lot more, for an appetizer see the anaolg stage with interesting details,e.g. the clever current booster transistors Q521/Q522 in the output of the I/V converter, or the lateral Fets in the output buffer...
Interested in how to use a fast Opamp in this buffer without oscillations?
I need some motivation to explain the proceedure, so I will go on here, when
say at least 10 people leave a post...
This player is the best, I ever heard...and I am not yet finished..
Have fun!
Philipp
 

Attachments

  • Sony Cdp XA7es analog stage.gif
    Sony Cdp XA7es analog stage.gif
    81.8 KB · Views: 273
  • decouple.pdf
    108.9 KB · Views: 62
  • current pulse patent.pdf
    200.8 KB · Views: 53
The CDP-XA7ES, and many other Sony players use a servo that operates on a 384fs clock and a digital filter and DAC that runs on a 512fs clock. 512/384 = 1.333, not a whole number, so normal clock division can't be used, yet these two clocks have to be synchronised. Sony's solution was a crystal filter, which allows it to sync the 384fs clock with the 512fs clock without having to resort to anything too complex.

The critical clock in this player is the 512fs (45.1584MHz) one, the one that clocks the DAC and digital filter, this is the one you should consider replacing. The other isn't even a true clock source, it's a divider.

So the short answer is; focus on the '45MHz' one, the '16MHz' one isn't very important (though isolating its supply is a good idea for noise reasons).
 

niamex

Member
2010-02-14 10:57 pm
Sofia
Having changed the power chord of my CDP XA7es player to two coax cables
with saftey ground connected to the shields sound quality improved a lot ..it almost reaches my heavily tweaked Kenwood DP 1100SG (built in LC clock, new OPAMPs etc.).
So I think it is very worthwhile to upgrade the clock(s)..has anyone found a solution for upgrading both clocks in this player (or simillar models)?
regards, Philipp

Will you please advise how to follow up your upgrade of the 1100 SG - I have the same and replaced almost all the caps on the board with ELNA RFS and the op amps with LMA but the sound is still not impressive.
Thanks,
Ignat
 
Hello Ignat,
this is a long story (you got the service manual ?) ..big step forward : take a Dip8 to two SMD adapter board and change the I/U converter Opamp directly after the DA converter to a high slew rate LME49713 current feedback type, the second on the board is for error correction can be a normal single LME49710 (SMD)..remove the cap across the feedback resistor (49713 will oszillate otherwise)..the LME49713 is the best for I/U conversion I tested so far (3000V/ys)..sound will get vivid,warm, full of body and detailed..
take a good clock and replace the crystal..
change the rectifier diodes for the power supply on the audio board to 1A Schotky diodes and remove the ceramic caps parallel to each diode..
For the other OPamps I took the LME49720 in metall case and heat sinked them..
but I/U converter is by far the most important..
hope this helps for the beginning, have fun, Philipp
 

limono

Member
2007-03-02 8:04 pm
Cool , I use X707ES as a transport , it's just too digital sounding as a player and sounds very 90' :) but it has great bass and relaxed sound as a transport. It is stock . I measured ESR of the PSU elna caps and they seem as good as new I was planning to change rectifier diodes to shottky and put 45 Mhz clock but don't know which one is good . So many choices one more expensive from another :) I need to change drawer belt so maybe I could get it upgraded a little in the same time