Hi all,
I've just got a used unit of Philips CD850 MkII. The appearance is excellent. But I'm wondering if it's been modified.
I'm certainly not an expect on CD player circuitry. I just opened the cover and saw whether there are any missing key components as mentioned in this Forum and other websites on the Internet.
All I can find are the following big black chips:
Philips PC74HCT373P
Philips PCB 83C654 P 026
Xicor X2816BP
Motorola ZC99827P
I can't find these:
TDA1541
LM833
Of course, I didn't check all the boards as I'm afraid to have problems after unscrewing boards out and putting them back on... 😛
Please help to cure my worry by letting me know what the above found chips are used for in layman terms and where I can find those missing but significant chips.
Thank you very much in advance. 🙂
mike
I've just got a used unit of Philips CD850 MkII. The appearance is excellent. But I'm wondering if it's been modified.
I'm certainly not an expect on CD player circuitry. I just opened the cover and saw whether there are any missing key components as mentioned in this Forum and other websites on the Internet.
All I can find are the following big black chips:
Philips PC74HCT373P
Philips PCB 83C654 P 026
Xicor X2816BP
Motorola ZC99827P
I can't find these:
TDA1541
LM833
Of course, I didn't check all the boards as I'm afraid to have problems after unscrewing boards out and putting them back on... 😛
Please help to cure my worry by letting me know what the above found chips are used for in layman terms and where I can find those missing but significant chips.
Thank you very much in advance. 🙂
mike
Um... I can find those small LM833's now. But where does the TDA1541 hide? Or is there no such chip in the MkII version? If so, what replaces it?
It says bitstream on the cd drawer front if i'm not mistaken:
there is no 1541 but a smd bitstream dac underneith the pcb.
Not shure which one, maybe somebody has the manual.
As for the chips, they all seem to be for controlling the player, not for the audio part.
there is no 1541 but a smd bitstream dac underneith the pcb.
Not shure which one, maybe somebody has the manual.
As for the chips, they all seem to be for controlling the player, not for the audio part.
yes, guido, it's Bitstream. i've just got the service manual. confirmed there is no TDA1541 as in CD850. i've been too stupid to suppose they use the same DAC.
guido, you're right too that the DAC is underneath the PCB. it's decoder SAA7310. No wonder I can't find it only with the top cover opened... 😛
from the service manual, i have more ideas about those found chips now. thanks a lot for your response, guido. 🙂
but i have a question, guido, what does "smd" stand for?
thanks to commstech too! you double confirmed one of the differences between CD850 and CD850 MkII!
who can point out more differences other than the above and the following mentioned by a user of this Forum?
CD850's THD apparently rises to very high levels the lower the output signal is - a faulty filter apparently. CD850II should have a fix on this issue.
mike
guido, you're right too that the DAC is underneath the PCB. it's decoder SAA7310. No wonder I can't find it only with the top cover opened... 😛
from the service manual, i have more ideas about those found chips now. thanks a lot for your response, guido. 🙂
but i have a question, guido, what does "smd" stand for?
thanks to commstech too! you double confirmed one of the differences between CD850 and CD850 MkII!
who can point out more differences other than the above and the following mentioned by a user of this Forum?
CD850's THD apparently rises to very high levels the lower the output signal is - a faulty filter apparently. CD850II should have a fix on this issue.
mike
TDA1540 said:
You are right again, TDA! The original CD850 has two SAA7321 chips for the DAC. The CD850MKii has one SAA7322 as a filter and one SAA7350 as the DAC. The CD850Mkii is very similar to the Marantz CD62 (and Arcam used a similar approach in the Delta 70.3). The original CD850 has no counterpart in the Marantz range.
Thanks, Arcamaniac, for pointing out clearly the DAC of CD850II! I had another mistake to say it is SAA7310... 😛
Btw, where can I learn more about the different chips and get the general knowledge of digital format and know how it works in CD player on the Internet? Any weblinks are welcome! 🙂
Btw, where can I learn more about the different chips and get the general knowledge of digital format and know how it works in CD player on the Internet? Any weblinks are welcome! 🙂
cartman said:
http://www.diyaudio.com/forums/showthread.php?s=&threadid=25039&perpage=10&pagenumber=1
can get a very good sound out of the cd850
allan
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