Pioneer DVD-A/SACD Player schematics wanted

[desjet]

Off course removing mute transistors will improve sound quality, but then you will have a "plopp" when unit is shut down (i knew this from a CD-63 tweak).
Installing a relais instead of would be the best way, but there's not much space to do this!

 

[Yves Smolders]

I'm thinking of doing this mod, but I would like to bypass the coupling caps entirely (want to go straight to 2 UcD400 amp modules that have their own coupling caps)

If I would "take" the signal *before* the coupling caps, but keep the caps on the board, will I have the same result than removing the caps and bypassing them with a wire?

I'd like to keep coupling caps on the normal outputs/scart/2 channel out, but add 2 special outputs without the caps coming into play.

Can this be done just by taking the signal before the caps?

I don't even understand why there are coupling caps on CD players anyway - aren't the modern D/A converters free of any DC component anyway?

Final question... in this layout, could a true balanced signal be taken, or is it simply not present?

Thanks

 

[krishu]

Hi,


you can't remove the coupling caps because there is about 5 V DC offset.

if you pick up the signal at the coupling caps you will "virtually" remove the muting transistors.

Kind Regards
Christian.

 

[Yves Smolders]

5V, wow

Is that due to bad design, or...?

 

[tobias_svensk]

Due to 12V+ (or whatever) to GND supply, instead of like +/-12V

 

[ctong]

I am also interested in the 999ES service manual. Could someone email me a copy? Thanks.

 

[dado1979]

Re: 2channel mod

Hi,
just working on a 868 tweak.
Replaced opamps with AD8620 (good solution because of single 12V voltage supply!) and replaced bypass (100µ) and coupling caps (47µ) with Black Gate FK. Wow, big improvement!

Hi, I'm new on the site. I have a Pioneer DV-868 and I'd like to make the same tweak that you made in 2005 (change the opamp with AD8620):
- is the OPA627 better than the AD8620?
- if I change only the opamp, should I change condenser (capacitator) too?
Thanks a lot Davide.

 

[mapelow]

627 is single 8620 is dual opamp so 627 won't fit. change caps if you like or just add film capacitor bypasses

 

[dado1979]

627 is single 8620 is dual opamp so 627 won't fit. change caps if you like or just add film capacitor bypasses

Sorry but my english is quite poor. What does it mean "add film capacitor bypasses"? I need to add capacitors or I can only change the capacitors of bypass? Thanks