Dear forum members ,
I'm looking for some background info about this CDM1 transport .
I own two Philips CD104 players in perfect condition .... not the last word in overall performance but would like brew a nice toploader CD drive in the future ( CDM1 seems a serious transport ) ..
Any advice is highly apreciated !!!
Happy Ears
I'm looking for some background info about this CDM1 transport .
I own two Philips CD104 players in perfect condition .... not the last word in overall performance but would like brew a nice toploader CD drive in the future ( CDM1 seems a serious transport ) ..
Any advice is highly apreciated !!!
Happy Ears
Attachments
I guess the best advice is already here:Happy Ears said:
http://www.diyaudio.com/forums/sear...d=394964&sortby=lastpost&sortorder=descending
and here:
http://www.diyaudio.com/forums/sear...d=394966&sortby=lastpost&sortorder=descending
Happy hunting
/Hugo
Congratulations Happy Ears!
What do you want to know?
Regarding the CD104 I have two tips:
-replace the output capacitor. A tantalium one I believe. This improves the sound quality a lot.
-In case of servo trouble check the connections between top- and bottomlayer of the PCB (resolder them).
The CD104 makes a nice start for a DIY project.
Have Fun!
Ward
What do you want to know?
Regarding the CD104 I have two tips:
-replace the output capacitor. A tantalium one I believe. This improves the sound quality a lot.
-In case of servo trouble check the connections between top- and bottomlayer of the PCB (resolder them).
The CD104 makes a nice start for a DIY project.
Have Fun!
Ward
CMD1
Thanks Guys !
Edum , I wanna use it as a stand alone drive with I2S outputs .
I could use the existing electronics for controle functions ... but I'm not sure where's best point to pick up I2S format ( didn't study the chip files yet ) and one could offer a perfect strategy here . I hope !
I guess power supply and system clock could be better too ...
I will read all earlier messages on the forum first . but any input of course could be valuable .
Yours,
Happy Ears
Thanks Guys !
Edum , I wanna use it as a stand alone drive with I2S outputs .
I could use the existing electronics for controle functions ... but I'm not sure where's best point to pick up I2S format ( didn't study the chip files yet ) and one could offer a perfect strategy here . I hope !
I guess power supply and system clock could be better too ...
I will read all earlier messages on the forum first . but any input of course could be valuable .
Yours,
Happy Ears
Using the existing controlfunctions will be the easiest way to get it working. Making you own controls is v. difficult (there is a post on that from a few weeks back). Your controls need to be adapted to the cdm type.
About i2s, the chipset is the probably the first one. So with the 14 bit DAC's. The decoder and error correction are separate chips, there is a dig filter and then 2 dacs. The decoder will decode 16 bits from the cd. So somewhere it goes from 16 bit into 2 times 14 bit (non i2s, mono dacs). I think before the dig filter, but i don't know if it is i2s there or something predating that spec.
Finding datasheets on the chips is difficult, i have only some ifo on the dac's. I do have a manual for the B&O cdx, i'll have a look in there, it has the timingdiagrams between all chips. Before anyone asks, it's too big to send around. My internet is still limited bandwith and i am not going to mail it around (yet).
GuidoB
About i2s, the chipset is the probably the first one. So with the 14 bit DAC's. The decoder and error correction are separate chips, there is a dig filter and then 2 dacs. The decoder will decode 16 bits from the cd. So somewhere it goes from 16 bit into 2 times 14 bit (non i2s, mono dacs). I think before the dig filter, but i don't know if it is i2s there or something predating that spec.
Finding datasheets on the chips is difficult, i have only some ifo on the dac's. I do have a manual for the B&O cdx, i'll have a look in there, it has the timingdiagrams between all chips. Before anyone asks, it's too big to send around. My internet is still limited bandwith and i am not going to mail it around (yet).
GuidoB
Hello Happy Ears,
Cdm0 (your photo) and cdm1 have complete analog electronics. So using the servo and control of the CD104 is a good idea.
First of all how much do you want to change? My tip of replacing the output capacitor makes a difference. But I guess you realy want some more
You can have an external DAC or maybe just replace the internal DACs.
I dived in some databooks and found a SAA7274 which translates Philips/Sony format to I2S. Looked at some DACs, checked a CD960(cdm1 and digital output) manual. Several options worthwhile to study
As I am not a digital expert I can not say how easy this options will turn out. I sugest you first try to get a service doc. I have the feeling that studying that service doc, chip files and work done by others on this forum you will find something feasable.
Have Fun!
Ward
Cdm0 (your photo) and cdm1 have complete analog electronics. So using the servo and control of the CD104 is a good idea.
First of all how much do you want to change? My tip of replacing the output capacitor makes a difference. But I guess you realy want some more
You can have an external DAC or maybe just replace the internal DACs.
I dived in some databooks and found a SAA7274 which translates Philips/Sony format to I2S. Looked at some DACs, checked a CD960(cdm1 and digital output) manual. Several options worthwhile to study
As I am not a digital expert I can not say how easy this options will turn out. I sugest you first try to get a service doc. I have the feeling that studying that service doc, chip files and work done by others on this forum you will find something feasable.
Have Fun!
Ward
Hi,
Had a quick look at my cdx manual (~philips cd104 inside ?). If you find SAA70xx inside, together with two TDA1540, you have the old 14bit chipset. The 7030 is the dig filter. Indeed 16 bit in and 14 bit out.
However, the 16 bit input is NOT I2S. There are four lines:
STR1 with a small pulse every 22.5 microsec (=1/f with samplefreq 44.1kHz) CLCF with 16 pulses after the STR1 pulse during 7.5 microsec. then 15 usec nothing. DLCF with 16 databits, clocked on CLCF pulses. Left channel only DRCF like DLCF, but now right channel.
Maybe some old BB DACS can handle this format (with STR1 inverted?). I only have some small diagrams used for checking the signals on a logic analyser. Not enough detail there to make
logic for conversion.
My advice would be to only fiddle around in the analog and PS department. The dig part is complicated and not compatibel it seems.
If you really want a CDM1 toploader i would suggest to buy a cd-x :-> And if you want one which has I2S, buy a cd-x 2 (cdm2,7210,7220,1541).
GuidoB
Had a quick look at my cdx manual (~philips cd104 inside ?). If you find SAA70xx inside, together with two TDA1540, you have the old 14bit chipset. The 7030 is the dig filter. Indeed 16 bit in and 14 bit out.
However, the 16 bit input is NOT I2S. There are four lines:
STR1 with a small pulse every 22.5 microsec (=1/f with samplefreq 44.1kHz) CLCF with 16 pulses after the STR1 pulse during 7.5 microsec. then 15 usec nothing. DLCF with 16 databits, clocked on CLCF pulses. Left channel only DRCF like DLCF, but now right channel.
Maybe some old BB DACS can handle this format (with STR1 inverted?). I only have some small diagrams used for checking the signals on a logic analyser. Not enough detail there to make
logic for conversion.
My advice would be to only fiddle around in the analog and PS department. The dig part is complicated and not compatibel it seems.
If you really want a CDM1 toploader i would suggest to buy a cd-x :-> And if you want one which has I2S, buy a cd-x 2 (cdm2,7210,7220,1541).
GuidoB
Data conversion possible ?
Hi Guys !
I checked the chips inside .. indeed SAA7020 / SAA7030 and double TDA1540 configuration .. must be one of the very first examples I guess .
Guido , does the CDX manual says how this data format is called ?? It would be very interesting to get some more info about this , there might be a possibillity to convert it into another ( more handy format , like I2S ) ?? purpose ... TDA 1543 / TDA 1541-R1 dac brews .
Ward , thanks too ! I believe If I cannot get the player run with the desired I2S streaming , I better choose another path .. like Guido mentioned .. or perhaps the CD2-pro package ... many ways that leads to Rome .
Let's wait ... who knows some digifreak is willing to share his expirience with the early data formats ... thought about asian wizzkids or Philips insiders key:
Happy Ears
guido said:
Hi Guys !
I checked the chips inside .. indeed SAA7020 / SAA7030 and double TDA1540 configuration .. must be one of the very first examples I guess .
Guido , does the CDX manual says how this data format is called ?? It would be very interesting to get some more info about this , there might be a possibillity to convert it into another ( more handy format , like I2S ) ?? purpose ... TDA 1543 / TDA 1541-R1 dac brews .
Ward , thanks too ! I believe If I cannot get the player run with the desired I2S streaming , I better choose another path .. like Guido mentioned .. or perhaps the CD2-pro package ... many ways that leads to Rome .
Let's wait ... who knows some digifreak is willing to share his expirience with the early data formats ... thought about asian wizzkids or Philips insiders key:
Happy Ears
Ok
I had another look (i have such a cdx, therefore i'm interested).e TDA1541 has a mode were you connect a separate dataline for left one for right channel. Look in the datasheet, this might just work. Forget about the 1543 or 1543A.
Connect
SAA7030 to TDA1541:
21 STR1 to 1 LE
18 CLCF to inverter (?) to 2 BCK
20 DLCF to 3 DATAL
17 DRCF to 4 DATAR
Connect pen 27 of the 1541 to -5V to get into the correct mode.
I am not a 100% sure, the data needs to be coded in offset binary and i don't know what the coding is to the 7030. I only have some info on the 1540 DAC, but the coding is not in the datasheet (????????).
Maybe the inverter is needed between CLCF and BCK, hard to tell from the picture i have, but it looks that way. Just try with and without.
One last thing, it looks easy now to make 2 mono 1541 dac with differential output. But the data is offset binary, so inverting the dataline wont work (not sure here, but it is not the coding used in I2S. BB has a nice application note on this, but i dont have it at hand).
Find some info on this type of coding if youre interested in using 2 1541's with diff output. What you can do is to feed one DAC with only left DATA and one with only right DATA. Then you can parallel the outputs, like they do in some designs on the net. But you can use one 1541 for right and one for left channel. Neat solution.
Give it a try and report back, i'm interested!
Regards,
GuidoB
I had another look (i have such a cdx, therefore i'm interested).e TDA1541 has a mode were you connect a separate dataline for left one for right channel. Look in the datasheet, this might just work. Forget about the 1543 or 1543A.
Connect
SAA7030 to TDA1541:
21 STR1 to 1 LE
18 CLCF to inverter (?) to 2 BCK
20 DLCF to 3 DATAL
17 DRCF to 4 DATAR
Connect pen 27 of the 1541 to -5V to get into the correct mode.
I am not a 100% sure, the data needs to be coded in offset binary and i don't know what the coding is to the 7030. I only have some info on the 1540 DAC, but the coding is not in the datasheet (????????).
Maybe the inverter is needed between CLCF and BCK, hard to tell from the picture i have, but it looks that way. Just try with and without.
One last thing, it looks easy now to make 2 mono 1541 dac with differential output. But the data is offset binary, so inverting the dataline wont work (not sure here, but it is not the coding used in I2S. BB has a nice application note on this, but i dont have it at hand).
Find some info on this type of coding if youre interested in using 2 1541's with diff output. What you can do is to feed one DAC with only left DATA and one with only right DATA. Then you can parallel the outputs, like they do in some designs on the net. But you can use one 1541 for right and one for left channel. Neat solution.
Give it a try and report back, i'm interested!
Regards,
GuidoB
CDM4/19
In the meantime also catched a CD380 player in excellent condition .
Lousy plastic case , but great potentials on the inside . CDM4/19 composite transport .. saa7210 decoder / xxx7220 interpolation filter / and funny enough a TDA 1543 dac .
Pretty easy player to build something serieus IMO . the 7210 provides I2S outputs at pin 37/38/39 .
Altough not as solid transport as the earlier generation , but still I believe many would be happy with it .
Any enlightment about the audible performance of the above transport in comparison with CDM 1 would be great .
So far I only compared between CDM12.1 ( Marantz CD53MKII )and CDM4 ( Marantz CD72MKII ) .... the latter IMO significantly better .
Happy Ears .
In the meantime also catched a CD380 player in excellent condition .
Lousy plastic case , but great potentials on the inside . CDM4/19 composite transport .. saa7210 decoder / xxx7220 interpolation filter / and funny enough a TDA 1543 dac .
Pretty easy player to build something serieus IMO . the 7210 provides I2S outputs at pin 37/38/39 .
Altough not as solid transport as the earlier generation , but still I believe many would be happy with it .
Any enlightment about the audible performance of the above transport in comparison with CDM 1 would be great .
So far I only compared between CDM12.1 ( Marantz CD53MKII )and CDM4 ( Marantz CD72MKII ) .... the latter IMO significantly better .
Happy Ears .
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