I know this has been done to death, and that's what I'm struggling with. there is so much information out there that I am finding it hard to decipher what's what. iv just spent the last 2 hours reading two threads and all it has done is give me a head ache. I would very much like to do a bit of modding with my cda94 but I cant see the woods for the trees at the moment. I can follow lines on a schematic and solder but as for designing a circuit or understanding how it all works is beyond me. I have been reading about different mods but a lot of the posts are just guys, with a lot better understanding than me, just chatting and bouncing ideas of each other.
can I be pointed in the direction of some well trodden paths to upgrade this chip, with specifics as to what to do. I have changed the opamps and done a nos mod so far. I have just been reading about a grundig dem mod but cant find a definitive set of instructions, maybe what I'm after is too basic for this forum.
any help would be greatly appreciated.
cheers adie
can I be pointed in the direction of some well trodden paths to upgrade this chip, with specifics as to what to do. I have changed the opamps and done a nos mod so far. I have just been reading about a grundig dem mod but cant find a definitive set of instructions, maybe what I'm after is too basic for this forum.
any help would be greatly appreciated.
cheers adie
Hi,
There are some thread about modding tda1541A cd player here :Marantz or Philips as the 360 cd player for instance.
There are a lot of options as going NOS, bypass filter chip to reduce jitter, changing caps, improve power supplies, add better 3 pins compatible regulators and to beginn change the aop buffer if not made discrete, i.e. a dip 8 operational amplifier after putting a dip8 sockett instead the original aop.
A better option if you have not an other tda1541A chip is to desolder it and evolve towards dac and dematerialized music with a new dac pcb (several kits on the markett) that will give you the best sound improvment but needs time investment to understand where you go and if it seems feasible for your hand skill.
On the light way of improving the cd94 that I don't know in particular but know well many Philips/Marantz tda1541A based cd player. I will replace the "filtering" capacitors between the powersupply until the main regulators but will leave in lieu the caps after the regulators for some reasonz that are often 78xx positive -xx is the voltage outputt- and negative 79xx.
Few caps most of the time : you just need to respect the uF capacitance number, the voltage ratting - never below that what is marked on the former cap- and the case size/leads spacing of course for the fresh cap to feet.
My preference will go with Panasonic FC or Elna Tonorex. Be carefull though, it's easy to make a short and flash the eprom chip of the cd... this one will not work anymore if so. Better to beginn with a less ambitious cdplayers : many second hands Philips/Marantz for few bucks in stores.
A curent tweak is also to remove the DC blocking caps before the RCA socket for film // with bipolar lytics... but keep the genuine one safe in case you prefere the after tweaking- they are often either Elna or green Nichicon and do sounds well despite the use and the capacitors agging.
There are some thread about modding tda1541A cd player here :Marantz or Philips as the 360 cd player for instance.
There are a lot of options as going NOS, bypass filter chip to reduce jitter, changing caps, improve power supplies, add better 3 pins compatible regulators and to beginn change the aop buffer if not made discrete, i.e. a dip 8 operational amplifier after putting a dip8 sockett instead the original aop.
A better option if you have not an other tda1541A chip is to desolder it and evolve towards dac and dematerialized music with a new dac pcb (several kits on the markett) that will give you the best sound improvment but needs time investment to understand where you go and if it seems feasible for your hand skill.
On the light way of improving the cd94 that I don't know in particular but know well many Philips/Marantz tda1541A based cd player. I will replace the "filtering" capacitors between the powersupply until the main regulators but will leave in lieu the caps after the regulators for some reasonz that are often 78xx positive -xx is the voltage outputt- and negative 79xx.
Few caps most of the time : you just need to respect the uF capacitance number, the voltage ratting - never below that what is marked on the former cap- and the case size/leads spacing of course for the fresh cap to feet.
My preference will go with Panasonic FC or Elna Tonorex. Be carefull though, it's easy to make a short and flash the eprom chip of the cd... this one will not work anymore if so. Better to beginn with a less ambitious cdplayers : many second hands Philips/Marantz for few bucks in stores.
A curent tweak is also to remove the DC blocking caps before the RCA socket for film // with bipolar lytics... but keep the genuine one safe in case you prefere the after tweaking- they are often either Elna or green Nichicon and do sounds well despite the use and the capacitors agging.
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hi, thanks for your response. sorry for the delay I'd some how missed it. caps ordered to do the main power supply board, so I'll see how that goes. going to pull some of the caps on the main board and measure them before jumping in to replace them all. ordered this if this is what you mean by "bypass filter chip" Nos reclock PCB for TDA1541A SAA7220 based dacs and players | eBay.
that will do for now I think.
that will do for now I think.
No problem, you're welcome.
Yes, I suggested to bypass that chip and trying NOS in the list, you understood correctly.
There is no full DAC kit that worths it on Ebay though. But if you need the cd player function. a lot can be done on a cd player. Just be carefull with short if it's your first cd player tweak... all seems good when after too much tweaks and a moment where you are not focused something happen because lack of experience : short most of the time, polarized cap in the bad position, a wire at the wrong vias, etc. It will be sad to break that cool high end CD player - I know I broken one day a very rare one despite some training
!
Best is to get the shematic of your dac and ask advices here if not sure or at leat to know where to beginn. A rule is never change more than a component and its sibling if dual channel then test and listening. Too much things moved without checking is a sword cut in water !
Yes, I suggested to bypass that chip and trying NOS in the list, you understood correctly.
There is no full DAC kit that worths it on Ebay though. But if you need the cd player function. a lot can be done on a cd player. Just be carefull with short if it's your first cd player tweak... all seems good when after too much tweaks and a moment where you are not focused something happen because lack of experience : short most of the time, polarized cap in the bad position, a wire at the wrong vias, etc. It will be sad to break that cool high end CD player - I know I broken one day a very rare one despite some training
! Best is to get the shematic of your dac and ask advices here if not sure or at leat to know where to beginn. A rule is never change more than a component and its sibling if dual channel then test and listening. Too much things moved without checking is a sword cut in water !
I've brought the ebay item listed in the above post. although it's not been delivered yet.
before I ordered I followed instructions here. Philips CD-630 CD player with TDA1541A DAC
before I ordered I followed instructions here. Philips CD-630 CD player with TDA1541A DAC
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Adie,
Do a full recap of the dac but don't change the dac itself (Certainly no nos mode!!!). With NOS mode the dac will have more distortion, and a sharper roll-off in the high frequencies. You can do the recap in stages. Elna silmic II to replace all the old Elna's, and as suggested in this thread the Nichicon bipolar. Give the TDA1541a a socket (precision) so you can change the IC to another one. They do sound different you know, as they were produced for 14 years on different machines (yours probably on the first steppers that Elcoma (Philips Nijmegen) used))....
The recap will take care of all the electrolytics that are not dried out, but not within spec anymore, and they only last for about 10-15 years (varies on use).
Use United Chemicon (low esr) or Panasonic (M) for the power supply part. Stay away from boutique parts like Mundorf or Audio Note.
Use Kemet SMR 5% (220-330) around the dac. Change the big caps (6800uf) to a higher capacitance (10-12000uf) will be enough.
The recap will give you a new dac, that is better than the one that left the factory in Japan, Sagamihara-shi. The development in capacitors has advanced quite a bit in thirty years....
Do a full recap of the dac but don't change the dac itself (Certainly no nos mode!!!). With NOS mode the dac will have more distortion, and a sharper roll-off in the high frequencies. You can do the recap in stages. Elna silmic II to replace all the old Elna's, and as suggested in this thread the Nichicon bipolar. Give the TDA1541a a socket (precision) so you can change the IC to another one. They do sound different you know, as they were produced for 14 years on different machines (yours probably on the first steppers that Elcoma (Philips Nijmegen) used))....
The recap will take care of all the electrolytics that are not dried out, but not within spec anymore, and they only last for about 10-15 years (varies on use).
Use United Chemicon (low esr) or Panasonic (M) for the power supply part. Stay away from boutique parts like Mundorf or Audio Note.
Use Kemet SMR 5% (220-330) around the dac. Change the big caps (6800uf) to a higher capacitance (10-12000uf) will be enough.
The recap will give you a new dac, that is better than the one that left the factory in Japan, Sagamihara-shi. The development in capacitors has advanced quite a bit in thirty years....
Why?
Certainly. New caps are smaller, cheaper and have lower ESR. Does this translate into better sound?
Not sure if this means you don't hear a difference, or you think you won't hear a difference...
If you don't you should be more specific. Which particular models and against what?
Why should I be more specific? I know I can not tell the difference between two brands of capacitors in a specific spot in a double blind test.
Putting a Panasonic FM or M in the power supply part of the CD94 will not make it sound better. You could also pick a Nichicon or Nippon Chemi-Con part for that matter.
I will look for low esr and endurance.
My CD 94 has a mix of Nippon Chemi-Con, Panasonic and Nichicon KG capacitors in the power supply part... Around the tda wima, and around the op amps Elna Silmic II.
Putting a Panasonic FM or M in the power supply part of the CD94 will not make it sound better. You could also pick a Nichicon or Nippon Chemi-Con part for that matter.
I will look for low esr and endurance.
My CD 94 has a mix of Nippon Chemi-Con, Panasonic and Nichicon KG capacitors in the power supply part... Around the tda wima, and around the op amps Elna Silmic II.
@ Adie moore : same but better don't change them, worst est than the spec and that's what you want if the lytic is just at the output pins. Most of the time it was Nichicon VX or VS, the last one often giving a 3D soundstage I noticed in some tda1541a Philips DAC.
I would use only the elna S II at the inputt pin of the regs.
For the main caps : tries with Pan FC and FR (not FM) , indeed some Nichicon KWR (a little lazy caps but all is about speaker and amp after, on the Pan FR side but the FR has more quality imho)
around the tda1541a instead of X5R : go for 0808 acrylic cap if they feet on the pads. Panasonic PPS 5% or Cornell Dublier FPA 20% : I like the last but you have to buy a little more and sort out for the precision as the values are low from o.1 uF to a little more often in Marantz/Philips DAC with that chip ! measure the value of the DEM timing cap : there you can use the Kemet, Wima (FP2 serie) or Vishay Roe blue one (I have a special like for the two last). vale if often between 400 & 800 pF on most models : measure and keep the same value... anyway it doesn't lock exactly most of the time.
For the outputt cap before the RCAs I will wait untill you listened each change : never change all at once : one tweak = always a test by listening.
the green "new" Nichicon bipolar will maybe not the one you need in relation with what you have around the player. As for NOS, it's subjective all is about the quality of the chips before, but the one we talk about is jitered to death... you can wait to do the tweak after having recaped and tuned, not before.
could you drop a photograph of top and underneath side of the pcb please to get an idea of the layout and parts ?
I would use only the elna S II at the inputt pin of the regs.
For the main caps : tries with Pan FC and FR (not FM) , indeed some Nichicon KWR (a little lazy caps but all is about speaker and amp after, on the Pan FR side but the FR has more quality imho)
around the tda1541a instead of X5R : go for 0808 acrylic cap if they feet on the pads. Panasonic PPS 5% or Cornell Dublier FPA 20% : I like the last but you have to buy a little more and sort out for the precision as the values are low from o.1 uF to a little more often in Marantz/Philips DAC with that chip ! measure the value of the DEM timing cap : there you can use the Kemet, Wima (FP2 serie) or Vishay Roe blue one (I have a special like for the two last). vale if often between 400 & 800 pF on most models : measure and keep the same value... anyway it doesn't lock exactly most of the time.
For the outputt cap before the RCAs I will wait untill you listened each change : never change all at once : one tweak = always a test by listening.
the green "new" Nichicon bipolar will maybe not the one you need in relation with what you have around the player. As for NOS, it's subjective all is about the quality of the chips before, but the one we talk about is jitered to death... you can wait to do the tweak after having recaped and tuned, not before.
could you drop a photograph of top and underneath side of the pcb please to get an idea of the layout and parts ?
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