Hi,
Picked up a B&O cd-x for little. Broken but worth the gamble
(15E). It is one of the first cd players around, cdm-1 transport and SAA70xx chipset with 2 times TDA1540. I am not sure yet if i can use it or just keep for parts, i'll see.
It is broken, somewhere there is a problem with the powersupply for the main pcb/cpu. Looking into that now, but some schematics might help :->
Anyone with schematics for this machine or the Philips CD104 (~equal machine) ??? Or more general, information on this chipset and some schematics of the digital decoder/filter and/or analog part (some linetransformers are used)??
Thanx in advance,
Greetings,
GuidoB
Picked up a B&O cd-x for little. Broken but worth the gamble
(15E). It is one of the first cd players around, cdm-1 transport and SAA70xx chipset with 2 times TDA1540. I am not sure yet if i can use it or just keep for parts, i'll see.
It is broken, somewhere there is a problem with the powersupply for the main pcb/cpu. Looking into that now, but some schematics might help :->
Anyone with schematics for this machine or the Philips CD104 (~equal machine) ??? Or more general, information on this chipset and some schematics of the digital decoder/filter and/or analog part (some linetransformers are used)??
Thanx in advance,
Greetings,
GuidoB
Got some life into it. Somebody poked around before me.
He/she managed to connect a powersupply connector to the output connector (output wires are direct connected on the pcb, so that connector should be empty). Since the output is connected to transformers there were some nice effects.
Ever seen -3V on the output of a 7812.........
Anyway, fixed that and a vapoured pcb track and now it does something: display switches on to '0000' and there is some reaction to play and stop: the display goes off for a moment.
However, no reaction on eject, so i think that the four connectors from the switches and the motor are also not connected correctly.
Guess if you could connect PS to the output, you could easily do something wrong there. They are on a small pcb nect to the main one, near the on/off switch. All are 3 pens.
Anyone with such a machine who could have a look inside????
Thanx
GuidoB
He/she managed to connect a powersupply connector to the output connector (output wires are direct connected on the pcb, so that connector should be empty). Since the output is connected to transformers there were some nice effects.
Ever seen -3V on the output of a 7812.........
Anyway, fixed that and a vapoured pcb track and now it does something: display switches on to '0000' and there is some reaction to play and stop: the display goes off for a moment.
However, no reaction on eject, so i think that the four connectors from the switches and the motor are also not connected correctly.
Guess if you could connect PS to the output, you could easily do something wrong there. They are on a small pcb nect to the main one, near the on/off switch. All are 3 pens.
Anyone with such a machine who could have a look inside????
Thanx
GuidoB
YES!!!!
hi,
i was right, there were more connectors swapped. After i got the information from someone (love the net), i got the thing to play again. Works well, no hickups, plays all..!
What is it:
- CDM1 transport, impressive piece of fine mechanics
- 2 times TDA1540 14 bit DACs with SAA70xx chipset (the first)
- 6 kg weight!! Huge metal subframe inside
- great looks, mechanised opening/closing
GuidoB
hi,
i was right, there were more connectors swapped. After i got the information from someone (love the net), i got the thing to play again. Works well, no hickups, plays all..!
What is it:
- CDM1 transport, impressive piece of fine mechanics
- 2 times TDA1540 14 bit DACs with SAA70xx chipset (the first)
- 6 kg weight!! Huge metal subframe inside
- great looks, mechanised opening/closing
GuidoB
Attachments
I have one to. It doesn't play high (40x and more) speed burned cdr's. It does play the older ones, though. I'm not sure if it's got a dirty laser or that it might lack the power to read cd's written in the modern fashion. I also own a cd502 (for 11 years now, never failed) with cdm4. This reads anything. Does anybody know if that should be the same with cdm1? How's your cdx playing these burned cd's?
regards
frenzic
regards
frenzic
Burning audio at 40 x is not the smartest thing to do.
Even with the best cd-writer it is much better to burn audio at 8x or preferably even less. Just burn one at 4x and compare it to the one written at 40x. The BER is also higher when writing cdr's at higher speeds. Something you don't want when you are after high quality of sound. Burning data is something else and can be done at higher speeds.
Especially reading of the original cd should be done with lower speeds to the harddisk instead of writing "on-the-fly". It'll avoid the plops and cracks you hear on cdr's written by people who don't know how to write audio-cdr's correctly. The plops and cracks are caused by the cdrom/dvdrom that spins at high rpm and fills the buffer, when the buffer is becoming empty the spindlemotor will suddenly spin up at high rpm and it will fill the buffer again causing the unwanted side-effects.
When reading the original cd it is also wise to do nothing with the pc except for waiting till the cd is read completely. Again, that only counts if you go for quality.
Common knowledge but still very true...
And btw, there are no transformers in the linestage. What i saw are relays. Seem to some kind of reed relays (glass tube) with the coil around it; looks like line-transformer.
Yes! Mute and deemphasis done with relays l! And that for '84.. Got NE5532 though, but i don't think i'll start upgrading.
It is fine as it is, a playing artifact.
Cannot use it for my dac either: no room inside and the master clock is ~4.4Mhz. Time for a cd-x 2 :->
GuidoB
Yes! Mute and deemphasis done with relays l! And that for '84.. Got NE5532 though, but i don't think i'll start upgrading.
It is fine as it is, a playing artifact.
Cannot use it for my dac either: no room inside and the master clock is ~4.4Mhz. Time for a cd-x 2 :->
GuidoB
@ Jean Paul
Indeed all of that's common knowledge. I actually have an audio only dedicated pc so that I do not lose any computing time on my regular workhorse and I get as little interference as possible. What I ment is that these days cdr's are written like cdrw's. A laser needs to be of higher intensity to read these tracks. I wondered if a cdm1 laser could do that. Because my cd-x doesn't.
Indeed all of that's common knowledge. I actually have an audio only dedicated pc so that I do not lose any computing time on my regular workhorse and I get as little interference as possible. What I ment is that these days cdr's are written like cdrw's. A laser needs to be of higher intensity to read these tracks. I wondered if a cdm1 laser could do that. Because my cd-x doesn't.
I am not sure what you mean, because you clearly wrote that it doesn't play 40x speed burned audiocd's.
Maybe you mean that cdr's reflect 50% compared to a normal cd and a cdrw reflects 25% compared to normal cd's ? A cdrw is NOT written like cdr as the technology differs. Certainly the high speed CDRW burners write with a technology that uses phase change techniques ( which in fact came from MO drives ). The format is also different, most of the time they're written in the UDF format.
CDM1 nor CDM4 don't have problems with cdr in general when they're in good shape. Some even read cdrw although they shouldn't play them because cdrw didn't even exist in their days.
When cdrw's are written like cdr's (which is possible of course ) my cdm's don't have a problem with them.
A CD50 is a japanese design. It has nothing to do with the philips made (hasselt? belgium) cd-x and the cd-x 2 which is philips design/components made by b&o !
Guido
http://www.beocentral.com/productinfo.php?familyid=BGCDX
Guido
http://www.beocentral.com/productinfo.php?familyid=BGCDX
Could it be the sample rate convertor in the CDR880 ? I had a CDR870 once and it was not good with cd to cdr copying because of the sample rate convertor wanting to convert things that needn't be converted. When used with analog inputs it was very good. But the CDR880 was supposed to have that flaw fixed I was told. My CDR765 and CDR570 ( crappy machines ) both make decent copies compared to pc copied ones. That is when they're used earthed as the SMPS in them strays RF like a FM transmitter.
In my experience with several cdwriters 12x is max when you want it to sound decent. The older Plextors are an exception, I could write faster without loss of quality.
Don't know about black Memorex. I use an NOS
batch of Kodak gold cdr's ( 6x max. ) for audio.@ frenzic
Phase change techniques are used for CDRW only. CDR writing is done in the old fashioned way. I still want to find out if Justlink, Justspeed and all those other buffer underrun features deteriorate sound quality when writing audio. As far as I can tell now I don't hear a difference but I have to admit I haven't put much time in a serious comparison.
That was what I would like to advise you. Please do it with cotton sticks, distilled water and Dreft ( soap variant ) or another mild detergent and leave the alcohol where it is.
jean-paul said:
Could it be the sample rate convertor in the CDR880 ? I had a CDR870 once and it was not good with cd to cdr copying because of the sample rate convertor wanting to convert things that needn't be converted. When used with analog inputs it was very good. But the CDR880 was supposed to have that flaw fixed I was told. My CDR765 and CDR570 ( crappy machines ) both make decent copies compared to pc copied ones. That is when they're used earthed as the SMPS in them strays RF like a FM transmitter.
In my experience with several cdwriters 12x is max when you want it to sound decent. The older Plextors are an exception, I could write faster without loss of quality.
Don't know about black Memorex. I use an NOS
@ frenzic
Phase change techniques are used for CDRW only. CDR writing is done in the old fashioned way. I still want to find out if Justlink, Justspeed and all those other buffer underrun features deteriorate sound quality when writing audio. As far as I can tell now I don't hear a difference but I have to admit I haven't put much time in a serious comparison.
That was what I would like to advise you. Please do it with cotton sticks, distilled water and Dreft ( soap variant ) or another mild detergent and leave the alcohol where it is.
Hi Jean-Paul
Can you name those old plextors?
Simply the older ones like PlexWriter 40/12/40A ( not that old ), PlexWriter 24/10/40A, the SCSI PlexWriter RW 4/2/20 and of course the PlexWriter 8/4/32A. I am not familiar with the newest models hence my remarks about the older series. I soom will try out a PlexWriter 52/24/52A at work when it arrives.
The Plexwriter 8/4/32A was a very fine drive and it was sold under the Creative brand too with half the amount of cache memory for a much lower price. Creative sold a lot and Plextor was not too fond of that because Creative sold more than they did. They seized production for Creative and Creative quickly switched to a Samsung drive which was not quite as good as the Plex but it was given the same product name !!!
In fact almost all old Plextors are good ( except the 32x Ultraplex cdrom drive which failed too much and made a lot of noise ). I once visited the company in Belgium with a drive that had problems after heavy use and although it was not common that customers visit the company for warranty issues I was helped in a decent way. The people checked the drive and told me to send the drive by post ( procedure ) which I did and after a few days I received a new drive. Very good warranty and repairservice which justifies the higher price they ask for their products.
I Never saw a better cdrom drive than Ultraplex 40max ( PX-40Tsi )
That one reads everything with abnormal high accuracy. Too bad I quit SCSI so I couldn't use it anymore. But when you want the best for copying audio nothing can beat a PX-40TSi.
Nowadays Plextor buys drives from other brands. Their DVD rewriter is a rebranded NEC for instance.
www.plextor.be
The Plexwriter 8/4/32A was a very fine drive and it was sold under the Creative brand too with half the amount of cache memory for a much lower price. Creative sold a lot and Plextor was not too fond of that because Creative sold more than they did. They seized production for Creative and Creative quickly switched to a Samsung drive which was not quite as good as the Plex but it was given the same product name !!!
In fact almost all old Plextors are good ( except the 32x Ultraplex cdrom drive which failed too much and made a lot of noise ). I once visited the company in Belgium with a drive that had problems after heavy use and although it was not common that customers visit the company for warranty issues I was helped in a decent way. The people checked the drive and told me to send the drive by post ( procedure ) which I did and after a few days I received a new drive. Very good warranty and repairservice which justifies the higher price they ask for their products.
I Never saw a better cdrom drive than Ultraplex 40max ( PX-40Tsi )
That one reads everything with abnormal high accuracy. Too bad I quit SCSI so I couldn't use it anymore. But when you want the best for copying audio nothing can beat a PX-40TSi.Nowadays Plextor buys drives from other brands. Their DVD rewriter is a rebranded NEC for instance.
www.plextor.be
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