Hi to all:
I am new to this forum. Been reading here and in the AA about non oversampling mods for the phillips TDA 1541 and have decided to go for it. Would appreciate the help of all who can contribute.
Plan to proceed with mods as a one piece CD player (not as a transport and DAC). This is more reasonable and supposedly gives "better results" avoiding extra cables and XS jitter. My Phillips CD80 is in excellent condition has seen little use myself being the only owner. This is important because supposedly the laser optical mechanism is no longer available NOS only second hand. But according to repair experts here what "usually fails in these units is the moving hinges not the laser itself". Therefore these venerable old units with the best of DAC chips deserve the updating effort. Supposedly once modded they will match or surpass most anything out there. As a matter of fact the recent Marants CD7 is basically a copy of these older models even using the old double crown TDA 1541 S2 chips. Many think it "outperforms" the top of the line Sony SCD1".
A brief history...The Phillips CD 80 followed the CD 960 in the late 1980s. It was considered one of the better units of its time. It had the heavy transport CDM1 (or CDM2?), cupper clad chassis, TDA 1541 S1 chips, digital out as both coax and toslink, two sets of analog out one being variable via remote control. Soon after Phillips started making CDPs more inexpensively with increased use of plastic and lighter construction but similar basic circuit albeit with cheaper components.
I actually have little knowledge of CPDs except for recent reading mostly here but have done some modding and amp construction primarily with tubes. Do have a digital camera and can post pictures as we go along.
From my readings mods should include:
1) PS upgrading of +/-5V digital supplies and 15V analog supplies
2) Additional regulated supplies ideally with their own transformers for the
a)output section (wether opamp , transistor , FET or tube) and
b) synchronous clock and FIFA or asynchronous clock-some question here wether async clocks cause "drop out artifacts"
Another consideration for the output stage is using a high turn ratio transformer with or w/o tube output. Some guys are apparently using ONLY the 1/15 or greater turn ratio transformer w/o tubes with the "best of results". Others claim it reduces dynamics etc.
3) Lose SPIDF, Lose digital filters and use I2S directly into DAC chip. May need to adjust for the dropping freq past 10K??
4) So called wildmonkeysect 8412 mod...is this really needed in one piece CDP since we are bypassing the similar chip in this CDP??
5) DAC better/larger bypass caps, parallel DAC chips.
6) Chassis and transport dampenig
7) RF contamination control.
Plus likely other mods as per members suggestions...these are the main ones that I considered important from my brief readings.
Each of the general mod topics above encompasses quite a bit of material but I would appreciate any and all discussions and suggestions of each of the mod topics above. Realize that although I read in general about these mods I really do not know how to actually carry them out in detail. For example how precisely do you get I2S and connect it to the DAC.
It seems to me that if we can document the modding process of this particular model then it will also apply to all the very similar and common TDA 1541 variants. Supposedly this is also the way to get the best sound....that is the modded single chassis CPD with the best nonoversampling chip the TDA1541. I also have the later more common Magnavox 650 with CDM4 chassis and 1541A chip which I will use to contrast inner designs.
Again advice comments in any form ie: directions to threads in this or other forum or web site are apreciated.
I am new to this forum. Been reading here and in the AA about non oversampling mods for the phillips TDA 1541 and have decided to go for it. Would appreciate the help of all who can contribute.
Plan to proceed with mods as a one piece CD player (not as a transport and DAC). This is more reasonable and supposedly gives "better results" avoiding extra cables and XS jitter. My Phillips CD80 is in excellent condition has seen little use myself being the only owner. This is important because supposedly the laser optical mechanism is no longer available NOS only second hand. But according to repair experts here what "usually fails in these units is the moving hinges not the laser itself". Therefore these venerable old units with the best of DAC chips deserve the updating effort. Supposedly once modded they will match or surpass most anything out there. As a matter of fact the recent Marants CD7 is basically a copy of these older models even using the old double crown TDA 1541 S2 chips. Many think it "outperforms" the top of the line Sony SCD1".
A brief history...The Phillips CD 80 followed the CD 960 in the late 1980s. It was considered one of the better units of its time. It had the heavy transport CDM1 (or CDM2?), cupper clad chassis, TDA 1541 S1 chips, digital out as both coax and toslink, two sets of analog out one being variable via remote control. Soon after Phillips started making CDPs more inexpensively with increased use of plastic and lighter construction but similar basic circuit albeit with cheaper components.
I actually have little knowledge of CPDs except for recent reading mostly here but have done some modding and amp construction primarily with tubes. Do have a digital camera and can post pictures as we go along.
From my readings mods should include:
1) PS upgrading of +/-5V digital supplies and 15V analog supplies
2) Additional regulated supplies ideally with their own transformers for the
a)output section (wether opamp , transistor , FET or tube) and
b) synchronous clock and FIFA or asynchronous clock-some question here wether async clocks cause "drop out artifacts"
Another consideration for the output stage is using a high turn ratio transformer with or w/o tube output. Some guys are apparently using ONLY the 1/15 or greater turn ratio transformer w/o tubes with the "best of results". Others claim it reduces dynamics etc.
3) Lose SPIDF, Lose digital filters and use I2S directly into DAC chip. May need to adjust for the dropping freq past 10K??
4) So called wildmonkeysect 8412 mod...is this really needed in one piece CDP since we are bypassing the similar chip in this CDP??
5) DAC better/larger bypass caps, parallel DAC chips.
6) Chassis and transport dampenig
7) RF contamination control.
Plus likely other mods as per members suggestions...these are the main ones that I considered important from my brief readings.
Each of the general mod topics above encompasses quite a bit of material but I would appreciate any and all discussions and suggestions of each of the mod topics above. Realize that although I read in general about these mods I really do not know how to actually carry them out in detail. For example how precisely do you get I2S and connect it to the DAC.
It seems to me that if we can document the modding process of this particular model then it will also apply to all the very similar and common TDA 1541 variants. Supposedly this is also the way to get the best sound....that is the modded single chassis CPD with the best nonoversampling chip the TDA1541. I also have the later more common Magnavox 650 with CDM4 chassis and 1541A chip which I will use to contrast inner designs.
Again advice comments in any form ie: directions to threads in this or other forum or web site are apreciated.
Hi, goldears,
I now do a player of transport Marantz CD95. Really untouched have remained only CDM1. All is altered. Five transformers cost(s, ten stabilized power supplies are altered and made anew. It is made new DAC on TDA1541A/S2. If it is interesting, its circuit can be looked here:
http://public.fotki.com/alean/audio/dac_tda1541a_.html
I now do a player of transport Marantz CD95. Really untouched have remained only CDM1. All is altered. Five transformers cost(s, ten stabilized power supplies are altered and made anew. It is made new DAC on TDA1541A/S2. If it is interesting, its circuit can be looked here:
http://public.fotki.com/alean/audio/dac_tda1541a_.html
Check those two threads:
http://www.diyaudio.com/forums/showthread.php?s=&threadid=23044
http://www.diyaudio.com/forums/showthread.php?s=&threadid=22542
IMHO, they represent the cutting edge in modding older Philips (Marantz) players (all complements to Rudolf, of course)
http://www.diyaudio.com/forums/showthread.php?s=&threadid=23044
http://www.diyaudio.com/forums/showthread.php?s=&threadid=22542
IMHO, they represent the cutting edge in modding older Philips (Marantz) players (all complements to Rudolf, of course)
Richard C said:I've got a couple of modified CD80s and haven't heard anything I like better.
Modifications: EVERYTHING has an effect.
Put a scope on the +v pin of the SAA7220...
How true. OSCONS do a good job there. Don't forget to change that silly pcb track to the decoupling cap. The only real error in CD80.
Hi, zyqibajt,
I shall try to attach plan to this post. Can it will turn out.
In photos some amplifiers are shown. These amplifiers of manual manufacturing.
Lamp are single-ended monoblocks on lamps GM70, 300 kg weigh.
Rectangular are semi-conductor amplifiers with controllable thermodynamic function.
I shall try to attach plan to this post. Can it will turn out.
In photos some amplifiers are shown. These amplifiers of manual manufacturing.
Lamp are single-ended monoblocks on lamps GM70, 300 kg weigh.
Rectangular are semi-conductor amplifiers with controllable thermodynamic function.
Attachments
I think it's not enough visible,yet.
At least to read values of the parts.
Alean ,your system is extremely interesting.
Do you have your own site with schematics and some philosophy?
Can anyone supply the picture of inside of CD 80,please?
I have never seen it opened.
I'm using Marantz CD 65MKII ,so all mods can apply,but i might go for CD 80.
Bartek
At least to read values of the parts.
Alean ,your system is extremely interesting.
Do you have your own site with schematics and some philosophy?
Can anyone supply the picture of inside of CD 80,please?
I have never seen it opened.
I'm using Marantz CD 65MKII ,so all mods can apply,but i might go for CD 80.
Bartek
Hi, answered a post,
Face values of elements not so are essential, they are considered.
Unfortunately I do not have own site. A little bit about philosophy it is possible to esteem on this site:
http://www.intexlabs.com/eng/index.htm
Face values of elements not so are essential, they are considered.
Unfortunately I do not have own site. A little bit about philosophy it is possible to esteem on this site:
http://www.intexlabs.com/eng/index.htm
Non OS with active mute mod
Located good source for NOS mod with active mute. This one is done on CD 960 which is basically same as CD80 or other similar TDA 1541 circuits. Mostly in Italian with some English translation
quite useful.
http://members.xoom.virgilio.it/hi_fi/
Enjoy and share
Roland
Located good source for NOS mod with active mute. This one is done on CD 960 which is basically same as CD80 or other similar TDA 1541 circuits. Mostly in Italian with some English translation
quite useful.
http://members.xoom.virgilio.it/hi_fi/
Enjoy and share
Roland
Post IV modular tube preamp and 600ohm attenuator
Decided instead of working initially on the CD80 to work first on a Magnavox 650 to get some practice with this circuit plus it has more space. It uses the plain vanilla TDA 1541 chip and CDM 4 chassis.
Have noticed several authors are using tube amplification after the IV and often also a transformer volume control (TVR). Since I already have many Altec 458A tube mic preamp modules I have considered using these instead. They have an input tranformer with 50-500 ohm input followed by two 6072 tubes then an output transformer typically with 600 ohms output. Was thinking of simply attenuating this line level signal via an Altec 600 ohm to 600 ohm attenuator which I already have. The output of this going then to a power amp
Any foreseable problems?? Seems transformers and tubes are usable in these digital circuits for a variety of reasons.
Also need advice regarding what clock update to use?? The question is wether to use a synchronous vs an asynchronous type. Presently more inclined to go with a synchronous type since not totally sure that an asynchronous clock won't allow loss of bits. What do you think?? Of course whatever clock choice is made should have its own decoupled PS. The same for the receiver and dac.
Any comments, criticisms, or advice again appreciated.
Roland
Decided instead of working initially on the CD80 to work first on a Magnavox 650 to get some practice with this circuit plus it has more space. It uses the plain vanilla TDA 1541 chip and CDM 4 chassis.
Have noticed several authors are using tube amplification after the IV and often also a transformer volume control (TVR). Since I already have many Altec 458A tube mic preamp modules I have considered using these instead. They have an input tranformer with 50-500 ohm input followed by two 6072 tubes then an output transformer typically with 600 ohms output. Was thinking of simply attenuating this line level signal via an Altec 600 ohm to 600 ohm attenuator which I already have. The output of this going then to a power amp
Any foreseable problems?? Seems transformers and tubes are usable in these digital circuits for a variety of reasons.
Also need advice regarding what clock update to use?? The question is wether to use a synchronous vs an asynchronous type. Presently more inclined to go with a synchronous type since not totally sure that an asynchronous clock won't allow loss of bits. What do you think?? Of course whatever clock choice is made should have its own decoupled PS. The same for the receiver and dac.
Any comments, criticisms, or advice again appreciated.
Roland
Any conclusions regarding Non OS vs 4x or less OS
In a fully modded TDA 1541 machine what sounds better the non OS or the 4x or less OS machine? Assume that most mods including reclocking etc were done. I ask because on Non OS machines I notice a lot of problems with HF noise also modulating as far down as 4K in freq!!. Apparently most of this remains poorly audible but has anybody compared these two versions and made some final conclusions? Would it be better to just update/mod the player but leave as 4X OS??
Roland
In a fully modded TDA 1541 machine what sounds better the non OS or the 4x or less OS machine? Assume that most mods including reclocking etc were done. I ask because on Non OS machines I notice a lot of problems with HF noise also modulating as far down as 4K in freq!!. Apparently most of this remains poorly audible but has anybody compared these two versions and made some final conclusions? Would it be better to just update/mod the player but leave as 4X OS??
Roland
That's the question I ask myself too with every Philips/Marantz I have. Till now I left them 4 x OS whereas my separate DAC is non OS. You can mod/update and later try non OS if you like. If you want an impression of how non OS sounds you can build a separate TDA1543 based DAC in a few days and compare the sound with the 4 x OS cdplayer.
TDA1541 mods
Apparently no definitive answer regarding NON OS vs OS?? Will proceed with switch controlled OS vs Non OS for definitive A and B testing. Wiil also remove filter board and also replace op amps with sockets to start A and B testing the variety of opamps available vs tube preamps modules. Thanks to all for input so far!!
Apparently no definitive answer regarding NON OS vs OS?? Will proceed with switch controlled OS vs Non OS for definitive A and B testing. Wiil also remove filter board and also replace op amps with sockets to start A and B testing the variety of opamps available vs tube preamps modules. Thanks to all for input so far!!
Opamp outputs
Been reviewing the opamp replacement possibilities for the output section and IV conversion. Although the sound quality likely will not come up to tube or suoerpair outputs the simplicity in their replacement may make them the choice for some.
I will include basic info here:
CDP outputs can be single or dual opamps. Browndog adapters can be used to make two single DIP or SOIC opamps into a dual DIP opamp. Browndog adapters run $2-3 a piece and making your own modulles can save you significantly. ie: LC Audio sells identical modules for $49!!
Best opamps to use are single browndog adapted to dual use for example AD 825, AD 826, AD 8065, OPA 627, OPA 637. Second best sometimes close to above are their dual cousins ie:
AD 8610, 8620. BB 2604, 2134.
Also instead of DIY it may be easier to buy your own additional regulated non digital +/- 5V, 15V power supplies. I seen these run $15 in Ebay!!. For beginners one of these PS to the new additional clock, old DAC chip, and output section along with updating the opamps and converting to non oversampling may be enough to keep you very happy.
Been reviewing the opamp replacement possibilities for the output section and IV conversion. Although the sound quality likely will not come up to tube or suoerpair outputs the simplicity in their replacement may make them the choice for some.
I will include basic info here:
CDP outputs can be single or dual opamps. Browndog adapters can be used to make two single DIP or SOIC opamps into a dual DIP opamp. Browndog adapters run $2-3 a piece and making your own modulles can save you significantly. ie: LC Audio sells identical modules for $49!!
Best opamps to use are single browndog adapted to dual use for example AD 825, AD 826, AD 8065, OPA 627, OPA 637. Second best sometimes close to above are their dual cousins ie:
AD 8610, 8620. BB 2604, 2134.
Also instead of DIY it may be easier to buy your own additional regulated non digital +/- 5V, 15V power supplies. I seen these run $15 in Ebay!!. For beginners one of these PS to the new additional clock, old DAC chip, and output section along with updating the opamps and converting to non oversampling may be enough to keep you very happy.
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