here it is Mooly, some where in the middle lampizator_DIY snip it
this bypass has served me many fun months then I switched to tube output
this bypass has served me many fun months then I switched to tube output
Hi Mooly,
I just do as you said in the image, i connect the + pin of c412 and c512 to RCA, via 1uF 250 V caps. sound natural however i receive a little noise. Once i touch the face of my amplifier (aluminum face) and noise decrease to almost gone.
I took mass to 2 - RCA jacks from the line of DAC 5th pin. Is this need more mass?
as this diagram
I just do as you said in the image, i connect the + pin of c412 and c512 to RCA, via 1uF 250 V caps. sound natural however i receive a little noise. Once i touch the face of my amplifier (aluminum face) and noise decrease to almost gone.
I took mass to 2 - RCA jacks from the line of DAC 5th pin. Is this need more mass?
as this diagram
An externally hosted image should be here but it was not working when we last tested it.
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More confusion,
I think I said to remove the muting transistors... post#11 here,
http://www.diyaudio.com/forums/digital-source/193857-mod-cdp-sony-950-a.html#post2659251
The only images I have drawn on are the ones posted on this thread... I've never mentioned a 1uF 250volts cap.
To do what you have done though requires you to isolate the mute circuit by disconnecting R407 and R507 (220 ohms). Also it's advisable to isolate the opamp outout with a small (100ohm or so) resistor for stability.
I've deleted my post #47 as I thought ide2003 meant the pin 1 and 7 bypass mod came from me... but I see he doesn't mean that... apologies.
If you have removed R407/R507 and the volume is low then either something has happened somewhere along the way or those 1uf caps are not all they could be.
When you mention noise that is reduced by touching the faceplate of your amp... well that points to a ground problem somewhere. Very hard to say without seeing exactly what you have done.
When you mention noise that is reduced by touching the faceplate of your amp... well that points to a ground problem somewhere. Very hard to say without seeing exactly what you have done.
no need for apologies Molly, as we here try to share our little nirvana's and door stops 
@ dovuhoang, that's ground problem, I have made my cdp to have earthing to the metal box, standard has no earth pin, also try to have shielded bypass cable, with shield soldered to pcb's analog ground, you can also try different ground point location
@ dovuhoang, that's ground problem, I have made my cdp to have earthing to the metal box, standard has no earth pin, also try to have shielded bypass cable, with shield soldered to pcb's analog ground, you can also try different ground point location
Hi Mooly,
Today i fixed the thing. only remove 2 of the mute transitor. last time i remove all 4 and i lost 1 chanel. It's really amazing.
Now i got a really musical sound from the CDP. I ever used Cambridge Azur 640C and Nakamichi CDP 4, and now see they are not in the class with my modded 950. haha, am i too opstimistic?
Thanks you Molly and ide2002 and chaotri and everyone for every step guiding me to the reall sound.
I think that is all for this project.
Cheers
Today i fixed the thing. only remove 2 of the mute transitor. last time i remove all 4 and i lost 1 chanel. It's really amazing.
Now i got a really musical sound from the CDP. I ever used Cambridge Azur 640C and Nakamichi CDP 4, and now see they are not in the class with my modded 950. haha, am i too opstimistic?
Thanks you Molly and ide2002 and chaotri and everyone for every step guiding me to the reall sound.
I think that is all for this project.
Cheers
happy that's work =)
could you make others pictures of the board to see exacly the final moves. if you can take picture of the bypass too because I just can hardly understand what you have done on this.
Other thing on the post #37 third picture, you replace 3 caps by one do you let the 2 other free ? or do you make something behind the board
my 950 is lost on postage service...wait and see... if I receve it /w a tda1541A too I'll have one left for who need for free just in exchange of the Shipping costs
could you make others pictures of the board to see exacly the final moves. if you can take picture of the bypass too because I just can hardly understand what you have done on this.
Other thing on the post #37 third picture, you replace 3 caps by one do you let the 2 other free ? or do you make something behind the board
my 950 is lost on postage service...wait and see... if I receve it /w a tda1541A too I'll have one left for who need
for free just in exchange of the Shipping costshappy that's work =)
could you make others pictures of the board to see exacly the final moves. if you can take picture of the bypass too because I just can hardly understand what you have done on this.
Other thing on the post #37 third picture, you replace 3 caps by one do you let the 2 other free ? or do you make something behind the board
my 950 is lost on postage service...wait and see... if I receve it /w a tda1541A too I'll have one left for who need
Hi, ah yes, 3 100uF caps i soldered it in other site of the board for space.
Hope u will soon have the CDP for your mod.
Cheers.
Hello here, I decide to start moding my cdp-750 (cause of I'll probably never see my 950.. f¤¤¤¤¤¤ postage service)
Dovuhoang
, I ve just read something about decoupling caps that you already change it's on this page but I read that in others forums.
[FONT=Courier New, Courier, monospace]
TDA1541A
[/FONT]
They speak about quality of caps to chose and preconise caps model (by order) MKS/MKP/MKT generaly by wima but not always
other important thing:
I take the sentence:
"......[FONT=Courier New, Courier, monospace]Most players use here 100 nF, the better players use 220nF. I swear that 220 sounds better than 100. I suggest to use 470nF by 63 V from WIMA.....[/FONT]"
I see that several times people change their 220 to 470 caps.
(my 750 already have 12x220nf and 2x100nf) and I think I'll go for 470....
and I don't know what is that but surely a next step for you
http://album.blog.yam.com/show.php?a=mmst&f=834272&i=67935829&p=10
Dovuhoang
[FONT=Courier New, Courier, monospace]
TDA1541A
[/FONT]
They speak about quality of caps to chose and preconise caps model (by order) MKS/MKP/MKT generaly by wima but not always
other important thing:
I take the sentence:
"......[FONT=Courier New, Courier, monospace]Most players use here 100 nF, the better players use 220nF. I swear that 220 sounds better than 100. I suggest to use 470nF by 63 V from WIMA.....[/FONT]"
I see that several times people change their 220 to 470 caps.
(my 750 already have 12x220nf and 2x100nf) and I think I'll go for 470....
and I don't know what is that but surely a next step for you
http://album.blog.yam.com/show.php?a=mmst&f=834272&i=67935829&p=10
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First time post, though I'm on Head-Fi and Audiokarma. Good to be here!
Old thread I know, but I picked up a CDP-950 that also has the TDA1541 non-A that the OP had in his. Sounds fine, but the player was cheap, so I can risk some mods to get better sound!
Just placed an order for a pair of OPA2604 and LM4562 opamps to roll in place of the 5532s. Have some OP275s from another project I can try as well.
I also ordered WIMA MKP (220nF) for decoupling and 470nF for the MSBs, as well as some new caps to replace the existing Duorex and Muse caps (going with a pair of new Muses for the 1000uF Duorex, Nichicon KA series for the 470uF old Muses, and Silmic II for the 4.7uF Duorex). It's not some master plan to use 3 different series of audio caps, but Mouser didn't have Silmic II's for all values, so I thought Muse was 2nd best, and since no 470uF in either of those lines, I went for the new KA series as the final pair.
Should be a fun set of mods, and will probably have to be the final step since the NOS mod seems more intricate. Though there's always the muting transistor mod.
Is removing the muting transistors a big improvement? I wasn't clear from the earlier posts whether it's a straight removal of all 4, since the OP said he removed only two (not sure which two though).
Old thread I know, but I picked up a CDP-950 that also has the TDA1541 non-A that the OP had in his. Sounds fine, but the player was cheap, so I can risk some mods to get better sound!
Just placed an order for a pair of OPA2604 and LM4562 opamps to roll in place of the 5532s. Have some OP275s from another project I can try as well.
I also ordered WIMA MKP (220nF) for decoupling and 470nF for the MSBs, as well as some new caps to replace the existing Duorex and Muse caps (going with a pair of new Muses for the 1000uF Duorex, Nichicon KA series for the 470uF old Muses, and Silmic II for the 4.7uF Duorex). It's not some master plan to use 3 different series of audio caps, but Mouser didn't have Silmic II's for all values, so I thought Muse was 2nd best, and since no 470uF in either of those lines, I went for the new KA series as the final pair.
Should be a fun set of mods, and will probably have to be the final step since the NOS mod seems more intricate. Though there's always the muting transistor mod.
Is removing the muting transistors a big improvement? I wasn't clear from the earlier posts whether it's a straight removal of all 4, since the OP said he removed only two (not sure which two though).
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