Technics cd player output - bypass these (resistors to ground) nor not

[MaccAu]

My Technics SL-P477a, already happy with it, but since upgrading the rca jacks, i was curious if i could bypass the resistors to ground. I left the compartor opamp in LM833, but changed the other to LME49860. I had old film capacitors sitting around from speakers i once had, so they had some hours on them and used them. I kept the same capacitance on the caps. I was shocked to hear that Elna is no longer manufacturing the SilmicII

Thank you
Sam

bypass or not possible the resistors to ground? if not i can leave it, sounds great as it is. The mechanism cdm4/19 is easy to come by, as i have spares.

 

[rayma]

That's a low pass filter set at around 500kHz. I would tend to keep it.

 

[MaccAu]

@rayma Thank you Ray. 47K to ground and in place of the capacitors, they have used resistors as well, is the low past filter. I will take your advice and keep it as is. Original caps were 22uf the 6.8uf film hasnt affected the player negatively.

 

[rayma]

You do need at least a resistor to ground due to the coupling capacitors.
They could make pops without the resistors.

 

[MaccAu]

@rayma that was my concern, so best to leave them. i added CMF resistors in the signal path, left the comparator opamp, changed the coupling capacitors and opamp, i'm happy with that, and will proceed to add the new rca sockets

 

[MaccAu]

I am wondering if i should replace the diodes D11-14 with Schottky ones, current are 1SR139-200TA , 1 A 200v Mix if silimicII and Fine Gold in the power supply. the 2200uf are 35v, not 16 like the original.

https://www.alldatasheet.com/datasheet-pdf/pdf/150939/EIC/1SR139-200.html

 

[rayma]

Parts are up to you, as long as they meet or exceed the originals.

 

[MaccAu]

@rayma thanks, I was thinking a little over the original specs just to be sure, as i could only find ROHM specs, but then maybe Technics used them, its a 1990 cd player. Any benefits with the Schottky diodes? - just those 4 where the AC comes in for the PSU

 

[rayma]

Schottky diodes are majority carrier devices, and so have virtually no reverse recovery.
They could be more quiet. Also their forward drop is lower.