Tube output is working... and not.
I added the tube stage after the 1540 (see diagrams posted earlier). Good news is that there is music and so dar as I can judge it is ok. Bad news is the additional sounds...
With additional sounds I mean :
- lots of hummmmmm...... well, that should be not too difficult to solve, perhaps the transistor schema suggested before. Or... Humm due to incorrect heater supply?? I noticed that the 6,3V supply does not give more then 5V!!! I need a bigger TX, the 6V 800mA probably gives not enough room for the TL1085.
- digital noises; When I press play there is this "weewee plop plop buzzzzz" before the music starts. The weewee plop plop stops then but the higher buzzzz continues through the music. It is like R2D2 does an intro before the music starts and then wisstles along.
The digital noise must be due to 2 things; first the removed muting stage, well nothing to do here I guess as that is gone forever and second the lack of filtering (except for the RC 22ohm/150nF after dac).
I can live with R2D2 doing the intro's but I want to get rid of the higher buzzz. Would anybody have a suggestion for a better method of filtering between dac and tubes?
Thanks,
Jeroen
I added the tube stage after the 1540 (see diagrams posted earlier). Good news is that there is music and so dar as I can judge it is ok. Bad news is the additional sounds...
With additional sounds I mean :
- lots of hummmmmm...... well, that should be not too difficult to solve, perhaps the transistor schema suggested before. Or... Humm due to incorrect heater supply?? I noticed that the 6,3V supply does not give more then 5V!!! I need a bigger TX, the 6V 800mA probably gives not enough room for the TL1085.
- digital noises; When I press play there is this "weewee plop plop buzzzzz" before the music starts. The weewee plop plop stops then but the higher buzzzz continues through the music. It is like R2D2 does an intro before the music starts and then wisstles along.
The digital noise must be due to 2 things; first the removed muting stage, well nothing to do here I guess as that is gone forever and second the lack of filtering (except for the RC 22ohm/150nF after dac).
I can live with R2D2 doing the intro's but I want to get rid of the higher buzzz. Would anybody have a suggestion for a better method of filtering between dac and tubes?
Thanks,
Jeroen
Attachments
JeroenR said:
Hi.
Hum possibly due to heaters or maybe the HT supply.
Try a battery supply for the heaters or disconnect while playing to see if the noise disappears.
Add more capacitors to HT.
It may also be due to too much current being drawn causing a drop in voltage - use regulator for lower HT as per my previous post.
For filtering, see Thorstens circuit for other dacs and adapt the filter [ use choke etc] He has posted a revised circuit I believe.
Cheers for now and good luck, JeroenR, I will be away now for 5 weeks or so.
Andy
poynton said:
Hi Andy,
Thanks again.
Have a great time on the Azores. 🙂
I'll keep posting.
Jeroen
CD104 Service Manual
It would appear that several participants in this thread have a copy of the CD104 Service Manual.
I have just been able to replace the CD104 that I foolishly scrapped about ten years ago(before I had web access and was aware of the mechanism it uses) and as I am sure that the replacement will benefit from some care and attention (replacement electrolytics etc) I would be very grateful if someone could send me a copy of the Service Manual (and any other relevant information). Please email it to :
mail DOT tcaas AT btinternet DOT com
Thanks in anticipation,
Geoff
It would appear that several participants in this thread have a copy of the CD104 Service Manual.
I have just been able to replace the CD104 that I foolishly scrapped about ten years ago(before I had web access and was aware of the mechanism it uses) and as I am sure that the replacement will benefit from some care and attention (replacement electrolytics etc) I would be very grateful if someone could send me a copy of the Service Manual (and any other relevant information). Please email it to :
mail DOT tcaas AT btinternet DOT com
Thanks in anticipation,
Geoff
glad to but 12Mb zipped !
if you have the quota then you should have mail by now. If not I'd guess your ISP doesn't allow such large attachments
if you have the quota then you should have mail by now. If not I'd guess your ISP doesn't allow such large attachments
The best tweak for a CD104 or CD304 would be to upgrade to a CD304mkII DAC board ---> 16 bit + digital out.
Could someone please send me the service manual so that I can continue my tweaks for the 104?
henkjohan "at" hotmail "dot" com
btw, this is my player so far 🙂
http://midiserver.student.utwente.nl/sitestuff/apparatuur/philips_cd_104/cd_104.htm
henkjohan "at" hotmail "dot" com
btw, this is my player so far 🙂
http://midiserver.student.utwente.nl/sitestuff/apparatuur/philips_cd_104/cd_104.htm
jives11 said:
ah no. one servicing guide made it, but the schematics didn't due to being 12.5Mb zipped. any other way to get this to you ?
sorry , that bounced too as too big. I can set you up a googlemail account if you like ?jives11 said:
CD104 Mod
Hi all
I modified a cd104
Decoder pcb: removed saa7030 (NOS)
In place of the two TDA1540p: two TDA1541a S1 ((parallel)
Power PCB 7917 replaced by 7915.
added 9705 on the heathsink.
nothing is cahanged in clocking
nothing is changed in I/V stage
result compare to non modified CD104 and 2 only NOS modified
(SAA7030 removed) one's the one with the 2 TDA1541a sounds IMHO far out the best. (round nice sound).
My wife (first violinist at the Rotterdam Phil) and son (trying to become a prof concert pianist) voted both for the 1541a parallel mod.
see attached foto
Hi all
I modified a cd104
Decoder pcb: removed saa7030 (NOS)
In place of the two TDA1540p: two TDA1541a S1 ((parallel)
Power PCB 7917 replaced by 7915.
added 9705 on the heathsink.
nothing is cahanged in clocking
nothing is changed in I/V stage
result compare to non modified CD104 and 2 only NOS modified
(SAA7030 removed) one's the one with the 2 TDA1541a sounds IMHO far out the best. (round nice sound).
My wife (first violinist at the Rotterdam Phil) and son (trying to become a prof concert pianist) voted both for the 1541a parallel mod.
see attached foto
Attachments
Re: CD104 Mod
Very interesting. Did you have to put some jumper cables across the 7030 holes ? (maybe after the photo was taken or you put the jumpers underneath the board
Onnosr said:
Very interesting. Did you have to put some jumper cables across the 7030 holes ? (maybe after the photo was taken or you put the jumpers underneath the board
Re: Re: CD104 Mod
Hi Jives
Thank you for replying on my posts.
I used a 24 DIL socket on the place of the SAA7000
This offers easy plug in Of the SAA7000 or a (second) 24 DIL socket with the four jumpers on it to compare NOS with 4xOS.
The TDA5141a is 16 bit so pin 16 from the SAA7000 has to stay low.
Next goal is to change to balanced DAC and try as I/V
two Beyer TR's (see photo) They have a balanced 25 ohm input !
In some post Guido Tent advised that.
But my problem is to learn how and wich signals
from the SAA7000 to one of the TDA1541a's I have to invert.
Perhaps you or somebody else can give me the light.
GRTZ
Onno
jives11 said:
Hi Jives
Thank you for replying on my posts.
I used a 24 DIL socket on the place of the SAA7000
This offers easy plug in Of the SAA7000 or a (second) 24 DIL socket with the four jumpers on it to compare NOS with 4xOS.
The TDA5141a is 16 bit so pin 16 from the SAA7000 has to stay low.
Next goal is to change to balanced DAC and try as I/V
two Beyer TR's (see photo) They have a balanced 25 ohm input !
In some post Guido Tent advised that.
But my problem is to learn how and wich signals
from the SAA7000 to one of the TDA1541a's I have to invert.
Perhaps you or somebody else can give me the light.
GRTZ
Onno
