Hello,
I'm tweaking my 227ESD. First of all I changed all caps, regulators for low dropout LM2990 & LM2937, I made some TDA1541A application mods, change LPF filter, OP-AMPs from NE5532 to BB627BP (DAC) and AD797 (in filter). I compare AD825, BB627, AD797 (next will be OPA134). I also changes diodes for digital section to BYV27-100.
Separate transformer for digital, analog, OPs, DAC and LC XO3 Clock hope will go soon.
Do You have any others suggestions for mods? Maybe anyone tried to tweak this CD? Right now I still try different caps. Till now I'm very suprised how the sound has changed. I hope 227ESD can even more... ;-)
I'm tweaking my 227ESD. First of all I changed all caps, regulators for low dropout LM2990 & LM2937, I made some TDA1541A application mods, change LPF filter, OP-AMPs from NE5532 to BB627BP (DAC) and AD797 (in filter). I compare AD825, BB627, AD797 (next will be OPA134). I also changes diodes for digital section to BYV27-100.
Separate transformer for digital, analog, OPs, DAC and LC XO3 Clock hope will go soon.
Do You have any others suggestions for mods? Maybe anyone tried to tweak this CD? Right now I still try different caps. Till now I'm very suprised how the sound has changed. I hope 227ESD can even more... ;-)
Hi zanash,
I have already damp it, almost everywhere ;-) As I said I change diodes for BYV27-100 and I think that was good turn. I didn't change for analog section but I'm thinking about BYV28-200 - these are very good. My friend (which has also the same CD player) have problems with using Shottky diodes (noise) so I don't have the same ;-) Of course it can be problem only for this diodes he has but You know.. better further from problems.
Does only I tweak this CD here?
)
I have already damp it, almost everywhere ;-) As I said I change diodes for BYV27-100 and I think that was good turn. I didn't change for analog section but I'm thinking about BYV28-200 - these are very good. My friend (which has also the same CD player) have problems with using Shottky diodes (noise) so I don't have the same ;-) Of course it can be problem only for this diodes he has but You know.. better further from problems.
Does only I tweak this CD here?
)I use 11 dq10's .......these ALWAYS improve the performance of even the most expensive players .......
has you friend removed the snubbers ? if not that will be a possible cause for noise.
Its common to see a considerable drop in the noise floor with schottkys as the do not create any switching noise.
Have you changed the rca sockets ? I always do this and rewire with at least silver in ptfe ...[no copper !]
Have you shielded all the chips and grounded the shields to the pcb ground plane ?
damp all the chips as well
damp the crystal to ...if you have not already done that !
damp the draw and tray ,....but don't foul the mechanism.
has you friend removed the snubbers ? if not that will be a possible cause for noise.
Its common to see a considerable drop in the noise floor with schottkys as the do not create any switching noise.
Have you changed the rca sockets ? I always do this and rewire with at least silver in ptfe ...[no copper !]
Have you shielded all the chips and grounded the shields to the pcb ground plane ?
damp all the chips as well
damp the crystal to ...if you have not already done that !
damp the draw and tray ,....but don't foul the mechanism.
Hi zanash,
thanks for Your reply,
>I use 11 dq10's .......these ALWAYS improve the performance of >even the most expensive players .......
>has you friend removed the snubbers ? if not that will be a >possible cause for noise.
My friend uses 11DQ09's but he didn't remove noise yet. Do You think 11DQ10's could solve this problem?
>Have you changed the rca sockets ? I always do this and rewire >with at least silver in ptfe ...[no copper !]
Not yet, but I want to do things like this at the end. I mean I want to do things which can more improve sound...
>Have you shielded all the chips and grounded the shields to the >pcb ground plane ?
No I haven't. Hmm it's quite ineteresting mod. Could You say sth more about it? With what material I should shield chips? Cu plate? So i.e. for TDA1541A ground to AGND or DGND which would be better? Is any thread 'bout it?
>damp all the chips as well
Hmm I think I don't understand ... If I put shield on the chip than I should put on the top damp, am I right?
>damp the crystal to ...if you have not already done that !
OK, I will, but first I put clock set.
>damp the draw and tray ,....but don't foul the mechanism.
I don't know what draw is but I damped whole tray where it was possible. Right now I'm thinking of using small springs and rubber tubes in it to separate mechanism from the chassis. This is how i.e. Philips did in CDs.
I put bypass, but I'm thinking for adding resistor on diodes. What do You think 'bout it? Have You tried this? Is it worth?
One more thing, I want to try also to use tantalum caps on regulators and maybe in other places.
Thx again!
thanks for Your reply,
>I use 11 dq10's .......these ALWAYS improve the performance of >even the most expensive players .......
>has you friend removed the snubbers ? if not that will be a >possible cause for noise.
My friend uses 11DQ09's but he didn't remove noise yet. Do You think 11DQ10's could solve this problem?
>Have you changed the rca sockets ? I always do this and rewire >with at least silver in ptfe ...[no copper !]
Not yet, but I want to do things like this at the end. I mean I want to do things which can more improve sound...
>Have you shielded all the chips and grounded the shields to the >pcb ground plane ?
No I haven't. Hmm it's quite ineteresting mod. Could You say sth more about it? With what material I should shield chips? Cu plate? So i.e. for TDA1541A ground to AGND or DGND which would be better? Is any thread 'bout it?
>damp all the chips as well
Hmm I think I don't understand ... If I put shield on the chip than I should put on the top damp, am I right?
>damp the crystal to ...if you have not already done that !
OK, I will, but first I put clock set.
>damp the draw and tray ,....but don't foul the mechanism.
I don't know what draw is but I damped whole tray where it was possible. Right now I'm thinking of using small springs and rubber tubes in it to separate mechanism from the chassis. This is how i.e. Philips did in CDs.
I put bypass, but I'm thinking for adding resistor on diodes. What do You think 'bout it? Have You tried this? Is it worth?
One more thing, I want to try also to use tantalum caps on regulators and maybe in other places.
Thx again!
Not yet, but I want to do things like this at the end. I mean I want to do things which can more improve sound...
I think you'd be suprised how nasty some pcb mount rca are !
No I haven't. Hmm it's quite ineteresting mod. Could You say sth more about it? With what material I should shield chips? Cu plate? So i.e. for TDA1541A ground to AGND or DGND which would be better? Is any thread 'bout it?
i use sticky back copper foil and ground to analouge ground
11dq10's .... are the minimum I use ....not tried 11dq09
I use tants on the opamps to decouple the power rails but nowhere else ...especially not the signal path
I think you'd be suprised how nasty some pcb mount rca are !
No I haven't. Hmm it's quite ineteresting mod. Could You say sth more about it? With what material I should shield chips? Cu plate? So i.e. for TDA1541A ground to AGND or DGND which would be better? Is any thread 'bout it?
i use sticky back copper foil and ground to analouge ground
11dq10's .... are the minimum I use ....not tried 11dq09
I use tants on the opamps to decouple the power rails but nowhere else ...especially not the signal path
I personaly would not add damping or anything else over the TDA1541 dacs.
I have a CDP-227esd and one of the dacs failed and monitoring of temperatures shows they run damn hot in normal use in this player, far more so than I remember in Philips players of yore that used them.
If I remember correctly others have reported failures of the same chips and seeing as supplies are slowly dwindling it would make sense to not push them over the thermal limits. I was lucky enough to buy a pair of single crown chips to fit in my player before they started to fetch silly prices on-line, £100+!
On the subject of opamps I've tried OPA2134 and did not like them at all, preferred the cooking JRC 5532's and only liked what a pair of OPA2604 do. As they say, YMMV.
I have a CDP-227esd and one of the dacs failed and monitoring of temperatures shows they run damn hot in normal use in this player, far more so than I remember in Philips players of yore that used them.
If I remember correctly others have reported failures of the same chips and seeing as supplies are slowly dwindling it would make sense to not push them over the thermal limits. I was lucky enough to buy a pair of single crown chips to fit in my player before they started to fetch silly prices on-line, £100+!
On the subject of opamps I've tried OPA2134 and did not like them at all, preferred the cooking JRC 5532's and only liked what a pair of OPA2604 do. As they say, YMMV.
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