I've read through the majority of this thread, and don't recall anyone having tried this idea. Would it be possible to bypass the output stage in these players as was done with the Sony PS1 or the Toshiba SD3950/60?
mrskinny said:
I, for one, am not sure what you mean.
Do you mean to take the output direct from the DAC out ??
Andy
Yes, that's what I meant. I'm not sure if the DACs would provide enough output voltage on their own without the opamps for this to work.
mrskinny said:
The TDA1540 DAC chips require an i/v stage of some sort.
A tube i/v stage was tried earlier in the thread by JEROENR but I do not know what stage it is at !!!
Andy
Quite a good idea 😉
This perfoboard is the PSU's filter right? Is it going to be inside the player or outside?
This perfoboard is the PSU's filter right? Is it going to be inside the player or outside?
simonov said:
thanks !
no ..tats the discrete 4 transistor output stage..the Psu diode & filter located just behind the cdm transport..+-18volts adj regulator on the big heatsink..
Hi Richardgreat
About that discrete I/V stage. I have a question. Does it still need the standard low pass filter at the output, generally used in the opamp stages?
Regards:
Venci
About that discrete I/V stage. I have a question. Does it still need the standard low pass filter at the output, generally used in the opamp stages?
Regards:
Venci
And just one more question. Yesterday a played a little with my CD582 and made the non oversampling mode. I found this to be quite a good improvement to the sound. Is it possible to do the same with my CD104? In general is it possible to run the TDA1540 at 0 x oversampling?
Regards:
Venci
Regards:
Venci
requesting serive manual
Hi all,
I finally dig up my CD104 player from my storage room. I bought it from e-bay several years ago, the seller claimed that it worked OK. When I got it, I noticed there was no sound from one of the channel but it played CD alright. Now, I power it on but the error led lights up. No sound! I read through all 41 pages of this thread and take notes. I also download the service manual from the web but later find out that the manual is incomplete. So if anyone has a complete service manual for CD104, would you mind sending it to me? My e-mail address is gundam083hk (AT) yahoo (dot) com
Thanks.
Johnny
Hi all,
I finally dig up my CD104 player from my storage room. I bought it from e-bay several years ago, the seller claimed that it worked OK. When I got it, I noticed there was no sound from one of the channel but it played CD alright. Now, I power it on but the error led lights up. No sound! I read through all 41 pages of this thread and take notes. I also download the service manual from the web but later find out that the manual is incomplete. So if anyone has a complete service manual for CD104, would you mind sending it to me? My e-mail address is gundam083hk (AT) yahoo (dot) com
Thanks.
Johnny
Hi.
If the player has been in storage for any time, The lens will almost certainly need cleaning.
Search this thread for 'griplets' and do the resoldering of them. Then recheck the player. Do a proper job!!!!!!!
No sound from 1 channel may be a bad solder joint or a faulty muting relay.
Andy
If the player has been in storage for any time, The lens will almost certainly need cleaning.
Search this thread for 'griplets' and do the resoldering of them. Then recheck the player. Do a proper job!!!!!!!
No sound from 1 channel may be a bad solder joint or a faulty muting relay.
Andy
Thanks. I have the same copy as your link provided. However, it is incomplete. The pages concerninig the decoder board are missing.
Johnny
Johnny
Yes you're right 
If you provide me with an e-mail capable of accepting up to 8MB massages I'll send you the full SM. The full file size is 12MB, so I'll send it via two e-mails.
Regards:
Venci
If you provide me with an e-mail capable of accepting up to 8MB massages I'll send you the full SM. The full file size is 12MB, so I'll send it via two e-mails.
Regards:
Venci
Thanks to jives11, simonov and poynton. You guys are really nice and helpful people. I have the full service manual now.
Hi guys,
yesterday I made the non oversampling modification on my CD104 by removing the SAA7030 chip and switching the SAA7000 directly to TDA1540. SAA7000 was set to 14bit mode of course 😉
The direct comparison between this CD104 and CD304 MKII (unmodified) revealed the obvious difference between these two players and both oversampling and non oversampling modes.
Removing the SAA7030 brought forward the dynamics hidden on the CD 😀
Anyone asking himself "to do NOS, or not to do NOS" should try this modification.
I made one more comparison. This time it was between TDA1540(with NOS) and TDA1541A(with NOS). Honestly listening to TDA1541A without oversampling makes my ears buzzing, ALTHOUGH the sound of 1541A is a bit more "juicy" and the first listening impressions are very positive. There's no such a ting when I listen to the TDA1540 DAC with removed oversampling.
Regards:
Venci
yesterday I made the non oversampling modification on my CD104 by removing the SAA7030 chip and switching the SAA7000 directly to TDA1540. SAA7000 was set to 14bit mode of course 😉
The direct comparison between this CD104 and CD304 MKII (unmodified) revealed the obvious difference between these two players and both oversampling and non oversampling modes.
Removing the SAA7030 brought forward the dynamics hidden on the CD 😀
Anyone asking himself "to do NOS, or not to do NOS" should try this modification.
I made one more comparison. This time it was between TDA1540(with NOS) and TDA1541A(with NOS). Honestly listening to TDA1541A without oversampling makes my ears buzzing, ALTHOUGH the sound of 1541A is a bit more "juicy" and the first listening impressions are very positive. There's no such a ting when I listen to the TDA1540 DAC with removed oversampling.
Regards:
Venci
NOS and Intermodulation distortion
I read with interest the various members accounts of applying the NOS modification. I am a great fan of the TDA1540, having a small collection of early Philips CD players from the CD100 to the CD304 with a CD104 probably being my favorite along with a Grundig CD1750 which is the best sounding Philips TDA1540 machine I have ever heard. I will probably try the NOS mod to see if I can hear any improvement.
However, I believed that the primary reason for the oversampling design in the first place was to place the artifacts produced by the digital process well outside of the audio frequency where they could be filtered out by a fairly gentle final low pass filter avoiding the intermodulation distortion that would otherwise be produced. The NOS mod surely negates this and would require a much steeper shelving filter (with the inherent problems that produces) to reduce the artifacts by the same amount. Are we in fact saying that the distortions introduced by the over-sampling method are greater than the distortion caused by not over-sampling?
I read with interest the various members accounts of applying the NOS modification. I am a great fan of the TDA1540, having a small collection of early Philips CD players from the CD100 to the CD304 with a CD104 probably being my favorite along with a Grundig CD1750 which is the best sounding Philips TDA1540 machine I have ever heard. I will probably try the NOS mod to see if I can hear any improvement.
However, I believed that the primary reason for the oversampling design in the first place was to place the artifacts produced by the digital process well outside of the audio frequency where they could be filtered out by a fairly gentle final low pass filter avoiding the intermodulation distortion that would otherwise be produced. The NOS mod surely negates this and would require a much steeper shelving filter (with the inherent problems that produces) to reduce the artifacts by the same amount. Are we in fact saying that the distortions introduced by the over-sampling method are greater than the distortion caused by not over-sampling?