Technics SL-PS770D mod possibilities question?

[FileFixer]

I`m thinking to doing some upgrades on my Technics SL-PS770D CD Player but I dont sure is it possible or not? I Also I`m not professional for electronics and some of these things I dont know too much. On schematics I see that some components and connection dont have too much logic and I suppose that some of that components can to be replaced with better components or maybe not.
This is my observation on this schematics what I can to see... Maybe I`m wrong?!

1. From IC803 pin14 signal goes to IC801 and provide clock signal from IC803 to IC801? Why not use same Quartz X801 to provide that frequency signal directly to IC801 but from IC803 (pin 15 or pin16), same place where clock signal goes to IC802?

2. As Difference amp is used 2 pieces of LM833 Op-Amps (IC804, IC805). Any better Op-Amp maybe can be replaced instead of these LM833? Maybe some of OPA, LM or AD Op-Amps?

3. Same thing as on point 2. IC806 Better Op-Amp?

4. Why this??? Low Pass filter on IC891 if we have low pass filter on IC806 and also on previous IC804 and IC805 (caps in parallel connection with resistor on its feedback). Thinking to remove that Low pass filter completely...?!

5. Removuing muting transistors Q803 and Q804?

What is your opinion, sugestions, possibilities on this? Is it some of that modifications possible or not? How much sound can to better?

This is pictures from schematics...

On these links you can to download complete schematics on JPG or PDF formats...

JPG
https://app.box.com/s/h8evl1vg00vh0n3feor8imctf58ma9r6
PDF
https://app.box.com/s/70fh8o4s44ex6co9gsuo7fujhmluf12i

 

[zebra03]

That's a heck of a Nice CD player to be messing with . I like mine just the way it is . But to each their own .

 

[FileFixer]

That's a heck of a Nice CD player to be messing with . I like mine just the way it is . But to each their own .

Of course that is nice CD player. I`m very satisfied with him. I`m only think that some components inside does not have too much logic or some of components can to be more better then is now. If i meybe do this replacement of some components I`m think to do these changes with professional tool and doing this with no less quality then any factory can to do. To the end this must to be done and look as factory do without many wires inside or on any way to look as some dirty work.

BTW... When I look today on this schematics I noticed another very interesting thing...
DACs have oscilator on 33.8688MHz (X801) and this frequency is shared to Digital filter (IC801) and this is ok but maybe this sharing path dont have logic, but ok this is correct when is DAC master in this case. System Control chip (IC401) have own frequency oscilator which is independent from previous DACs and System Control chip and this IC401 work on 4.23Mhz. This is exactly eight times less from 33.8688MHz on X801. So, I`m thinking why Technics can not use same master frequency from X801 and divide X801 frequency eight times less and share exact 4.2336Mhz to IC401? Actual connection with two different frequency oscilators is not to much smart decision from my point of view and also IC702 Servo processor have its own oscilator on 16.9344MHz which is exact double less frequency from 33.8688MHz on X801. Technics use three different quartz oscilators instead of only one oscilator which can to be divide on two and eight times and any other chips inside CD Player can to be in slave mode if that base frequency signal come from DAC IC802 pin14.